entry level lights to see by

[Dan O]

Around the cusp of the dark solstice...

It *was* going to be a shootout: Planet Bike Blaze 2-watt vs.
Portland Design Works Cosmic Dreadnaught 110 - head-to-head, side-by-
side on opposite sides of the handlebar stem.

First impression (of the combo w/ Dreadnaught): These two lights -
with many remarkable similarities and differences - got together and
*complemented* each other.

We know how I have used and generally like PB Blaze headlights for
what they are - except for that *enormously* disillusioning
(disilluminating?) rain experience:

http://groups.google.com/group/rec.bicycles.tech/msg/9a052e6335b836c8

So when I saw the PDW headlight, purportedly "Built to withstand
rain... " and seemingly priced to compete with the 2-watt PB Blaze, my
interest was piqued. Unfortunately, PDW did *not* see fit to sponsor
me a light; but when I saw it on Amazon for thirty-some bucks and free
super saver shipping, I sprung for it (so now they'll get the totally
unvarnished review).

As noted, the similarities are remarkable: Compact LED self-contained
2xAA "folded penlights", either can snap on to the other's bracket.
(The PDW guys are former PB guys.) MSRP about exactly the same.
High, low, and blinking modes.

For such similar products, the differences are remarkable. PB button
switches low, high, blinkety-flash, PDW high, low, blink-blink. PB
blinkety-flash mode is crazy attention-getting (SuperFlash (TM), PDW
goes blink, blink, blink. (Well, those are piddly differences, but
wait... )

PB has a nice (I think) round, far reaching spot with useful
attenuated spill (?) spread outside the spot. PDW has a more squarish/
rectangular beam and gobs of side spill through two side windows much
bigger than the PB side windows (which I've kind of obscured anyway
with my Saran wrap waterproofing mod). PDW spills relatively bright
light onto the handlebar, the fork crown, water bottles, my legs...
kind of distracting (bright enough that looking down can cause my eyes
to need to re-ajust when looking back up). Probably better for "being
seen" from off center, I guess.

The PDW produces pretty good light to see by - even on low. So did
the PB. The PDW actually looks brighter, but I know this can be very
much a peak battery thing, and all my NiMH's are pretty old and of
suspect capacity, so not sure yet. But... the two of them together
both on high are pretty awesome (complementary).

Must break in here with a huge difference: The PB is a snap to change
batteries (well, used to be a snap before the snap catch wore smooth
and doesn't "snap" anymore - but it doesn't fall open either, so... )
Anyway, the PB is easy to change batteries, twist the head and it pops
off to dump spent and drop fresh batteries, twist and go. The PDW has
a friggin' *screw* holding the fiddly cover, over a more typical lay-
in battery tray. This would be understandable if it weren't for the
fact that the PB battery compartment never had a problem with
wetness. (Must be a patent thing.)

In light of (ha-ha) the huge difference in battery change convenience,
and the bracket slide-on compatibility, it occurred to me that the PB
light could be a primary daily (nightly) headlight, with the even more
compact (barely bigger than a spare pair of batteries) PDW stowed in
the messenger bag as backup - maybe with some sort of batteries with
less tendency self-discharge when installed.

Well, getting long for initial impressions. But anyway in a world
where the next class of bike headlights seems to jump in price about
3x, these two ~cheap little lights together - at less than a hundred
bucks total - produce a lot of light - or ~adequate light for longer
runtime and a variety of modes separately or combined.

[Dan O]

Second ride impressions: The PDW is kicking the PB's ass in terms of
"brightness". When starting one and then the other the PDW light
swamps the PB. I think it may have much better batteries in it; we'll
see when I start swapping. ISTR the PB giving brighter light when
loaded with good, fresh batteries, but isolated subjective
impressions... The PDW seems to be holding "brightness" longer than
the PB did, though.

However, I call it "brightness" in quotes because it's just
subjectively... well, "bright" (could be color, or intensity, or... )
The PB by itself seems just as good to see by (maybe better, since I'm
not noticing the light itself so much as the illuminated road ahead).
And in fact, when I rolled up to the kitchen door, the two lights
(both on solid high) were reflected in the kitchen window and the
reflected PB light looked maybe a bit brighter.

The handlebar mounts are not good for lateral aim adjustments (about
all you can do is tweak at them), and last night while riding on the
paved shoulder, I noticed that I was getting plenty of illumination
across the fog line onto the road (where there is not going to be
anything to watch out for), and not as much as I'd like off the road
edge to the right (will work on lateral aiming). Internet reviewers
seem to like the screw clamp PDW thing better, but I like the PB cam
clamp, which is easier to adjust on the fly (good for aiming down as
the batteries weaken). The cam clamp *does* occasionally come open
inadvertantly, but doesn't fall off when it does. I might have to
look at mounting on the front rack.

I sometimes pass another guy who apparently commutes in the opposite
direction on part of my route, and he's always had a very bright
headlight. I passed him again last night, and it looks like Santa
brought him a pair of new retina burners. He had one mounted on his
head. I thought the aliens were coming.

[datakoll]

compare to similar priced Cateyes ?

helmet lights are essentail to see where ura goin noit where the bike is headed.

try one on the lower fork ? maybe yellow ?

[SMS]

On 12/29/2012 12:40 AM, Dan O wrote:

> The PDW produces pretty good light to see by - even on low. So did
> the PB. The PDW actually looks brighter, but I know this can be very
> much a peak battery thing, and all my NiMH's are pretty old and of
> suspect capacity, so not sure yet. But... the two of them together
> both on high are pretty awesome (complementary).

While more slightly more expensive than the PDW Spaceship, the $28.20
UltraFire SH-3AA Cree XM-L T6 800LM 5-Mode is what I've switched to. It
uses three AA batteries (side by side, not linearly). They claim 800
lumens, but I doubt that this is the case, 200 lumens on high is
probably more accurate. But you don't need it on high very often, the
low and mid settings are usually enough. It will run on three AA
batteries or one Li-Ion 26650. A 26650 is about 5000mAH at 3.7V while
three Sanyo Eneloop NiMH batteries will give you only 2000mAH at 3.6V.
You could also use an 18650 battery with an adapter sleeve and get about
3000mAH at 3.7V.

The big advantage, IMVAIO is that I can use a better mount. I want a
"grab and go" light where the mount has no moving parts to remove the
light, AND where the clamp can be rotated side to side as well as up and
down (because some of the bicycles that the light is used on have curved
handlebars).

Mount: <http://nordicgroup.us/s78/images/IMG_0303.JPG> (not the
Ultrafire light in the holder).

Light:
<http://dx.com/p/ultrafire-sh-3aa-cree-xm-l-t6-800lm-5-mode-memory-white-led-flashlight-w-strap-3-x-aa-1-x-26650-124061>

[Frank Krygowski]

On Dec 29, 3:41 am, Dan O <danover...@gmail.com> wrote:
>
>
> Second ride impressions:  The PDW is kicking the PB's ass in terms of
> "brightness".  When starting one and then the other the PDW light
> swamps the PB.  I think it may have much better batteries in it; we'll
> see when I start swapping.  ISTR the PB giving brighter light when
> loaded with good, fresh batteries, but isolated subjective
> impressions... The PDW seems to be holding "brightness" longer than
> the PB did, though.
>
> However, I call it "brightness" in quotes because it's just
> subjectively... well, "bright" (could be color, or intensity, or... )
> The PB by itself seems just as good to see by (maybe better, since I'm
> not noticing the light itself so much as the illuminated road ahead).
> And in fact, when I rolled up to the kitchen door, the two lights
> (both on solid high) were reflected in the kitchen window and the
> reflected PB light looked maybe a bit brighter.

I wonder if you're reacting to what you described as a greater amount
of spill in the beam of the PDW. I see elsewhere that both lights
have spot beams, which is kind of a shame. (IME shaping a beam to fit
the road is much more effective than pumping more lumens into a
spot.) But perhaps the spill of the PDW gives some of the same
effect?

> The handlebar mounts are not good for lateral aim adjustments (about

> all you can do is tweak at them)...
> ... I might have to

> look at mounting on the front rack.

I think mounting at a height just above the front wheel works best,
giving an optimum combination of throw and pothole shadows (which you
need). If you have a front rack, you could buy or fabricate something
to hold the light there, and take care of your aiming issues as well.

A couple more comments: You mentioned the snaps on the PB battery
case getting worn. I'd strongly consider reinforcing that with a
rubber band cut from an old inner tube, if possible. I used to lead a
lot of night rides, and I've seen several (other brands) of lights pop
open and lose bits when riders hit bumps.

If you get a chance, compare your setup with a with a modern LED
generator light that fits German beam specs. The difference can be
amazing.

- Frank Krygowski

[Dan O]

On Dec 29, 9:52 am, Frank Krygowski <frkry...@gmail.com> wrote:
> On Dec 29, 3:41 am, Dan O <danover...@gmail.com> wrote:
>
>
>
>
>
> > Second ride impressions: The PDW is kicking the PB's ass in terms of
> > "brightness". When starting one and then the other the PDW light
> > swamps the PB. I think it may have much better batteries in it; we'll
> > see when I start swapping. ISTR the PB giving brighter light when
> > loaded with good, fresh batteries, but isolated subjective
> > impressions... The PDW seems to be holding "brightness" longer than
> > the PB did, though.
>
> > However, I call it "brightness" in quotes because it's just
> > subjectively... well, "bright" (could be color, or intensity, or... )
> > The PB by itself seems just as good to see by (maybe better, since I'm
> > not noticing the light itself so much as the illuminated road ahead).
> > And in fact, when I rolled up to the kitchen door, the two lights
> > (both on solid high) were reflected in the kitchen window and the
> > reflected PB light looked maybe a bit brighter.
>
> I wonder if you're reacting to what you described as a greater amount
> of spill in the beam of the PDW.

Nope, I don't think so. I think I'm assessing the pure brightness of
the spot. The exorbitant "spill" of the PDW I was talking about is
all over the bike right under me, and only noticed when I look down at
it; the spot is way up the road.

The "swamping" is like this: When I turn off both lights, then turn
on the PDW, then turn on the PB, I don't even notice the spot of the
PB hit the road. When I turn off both lights, then turn on the PB,
then turn on the PDW, the PB spot disappears and is replaced by the
PDW spot.

> I see elsewhere that both lights
> have spot beams, which is kind of a shame. (IME shaping a beam to fit
> the road is much more effective than pumping more lumens into a
> spot.)

These are little battery penlights. They need to pump as much light
into the spot as they can. (Impressive as it is, it's still arguably
inadequate.)

> But perhaps the spill of the PDW gives some of the same
> effect?
>

I am already familiar with the PB, so comparison is greatly biased at
this point, but I really like the PB. The spot is pretty bright but
not glaringly so, is pretty good sized (not pinpoint) well up the road
ahead, and is surrounded by attenuated light that speads all around
the spot, with modest "local" spill that gives a faint shadowing of
the front rack on the road right in front of me.

The PDW (which I'm not accustomed to yet) gives a very bright spot
(maybe relatively glaringly so) - less round but no more useful IMO,
and this brightness actually detracts from the effectiveness of
whatever surrounding spill. The *local* spill (right around the
headlight itself and on and near the bike) of the PDW is downright
disconcerting to me (when I look down and see it, and I suppose it's
always there in my peripheral vision).

Out in the country where it's actually dark, I am generally less
concerened with what's on the road ahead and to the left than with
what might be laying on the shoulder or getting ready to pop out of
the ditch.

> > The handlebar mounts are not good for lateral aim adjustments (about
> > all you can do is tweak at them)...
> > ... I might have to
> > look at mounting on the front rack.
>
> I think mounting at a height just above the front wheel works best,
> giving an optimum combination of throw and pothole shadows (which you
> need). If you have a front rack, you could buy or fabricate something
> to hold the light there, and take care of your aiming issues as well.
>

The front rack is a Surly Nice Rack, with a top platform and even a
braze-on at center forward. The chief drawback consideration is that
I'm accustomed to switching the light between modes while riding (can
sometimes even get an oncoming car to lower their high beams by
flashing them). If I ever get a serious lighting system with wires, I
think I'd like to mount the headlight on the front rack, and wire a
switch up to the handlebar.

> A couple more comments: You mentioned the snaps on the PB battery
> case getting worn. I'd strongly consider reinforcing that with a
> rubber band cut from an old inner tube, if possible. I used to lead a
> lot of night rides, and I've seen several (other brands) of lights pop
> open and lose bits when riders hit bumps.
>

I've had a headlight fly apart a couple of times, but both times it
popped off the mount first (may have been my own failure to fully
secure the catch each time) and then blew apart on the road (one was
then run over by a bus and destroyed as I waited to retrieve it).
I've assessed the worn PB head attachment, and don't especially like
it; but it's not prone to undoing itself (yet) (requires a twist), and
I do like the ease of access to change batteries.

> If you get a chance, compare your setup with a with a modern LED
> generator light that fits German beam specs. The difference can be
> amazing.
>

I've no doubt it would be, and would like to get such a chance.
(Didn't want to turn this into a debate about penlight vs. *real* bike
lights, and appreciated the tone of your response very much.) I have
found the improvement from the lights of yore (2xC cell 'T' head leg
strap incandescent flashlight, and bottle dynamo driven incandescent)
with these amazing LED's. I know there are much better solutions, but
the PB 2-watt has worked great for me, and the PDW seems on the march
to ever brighter LED output - at thirty-some bucks delivered with
batteries included.

[Dan O]

On Dec 29, 7:40 am, SMS <scharf.ste...@geemail.com> wrote:
> On 12/29/2012 12:40 AM, Dan O wrote:
>
> > The PDW produces pretty good light to see by - even on low. So did
> > the PB. The PDW actually looks brighter, but I know this can be very
> > much a peak battery thing, and all my NiMH's are pretty old and of
> > suspect capacity, so not sure yet. But... the two of them together
> > both on high are pretty awesome (complementary).
>
> While more slightly more expensive than the PDW Spaceship, the $28.20
> UltraFire SH-3AA Cree XM-L T6 800LM 5-Mode is what I've switched to. It
> uses three AA batteries (side by side, not linearly). They claim 800
> lumens, but I doubt that this is the case, 200 lumens on high is
> probably more accurate. But you don't need it on high very often, the
> low and mid settings are usually enough. It will run on three AA
> batteries or one Li-Ion 26650. A 26650 is about 5000mAH at 3.7V while
> three Sanyo Eneloop NiMH batteries will give you only 2000mAH at 3.6V.
> You could also use an 18650 battery with an adapter sleeve and get about
> 3000mAH at 3.7V.
>

Sounds intriguing (though I had the impression that the PDW Spaceship
was not in the league of light output to see by that I have with the
PB Blaze 2-watt).

How does it fair in the monsoon season?

<snip>

[Dan O]

On Dec 29, 12:21 pm, Dan O <danover...@gmail.com> wrote:
> On Dec 29, 9:52 am, Frank Krygowski <frkry...@gmail.com> wrote:
>
>
>
> > On Dec 29, 3:41 am, Dan O <danover...@gmail.com> wrote:
>

<snip>

>
> > > The handlebar mounts are not good for lateral aim adjustments (about
> > > all you can do is tweak at them)...
> > > ... I might have to
> > > look at mounting on the front rack.
>
> > I think mounting at a height just above the front wheel works best,
> > giving an optimum combination of throw and pothole shadows (which you
> > need). If you have a front rack, you could buy or fabricate something
> > to hold the light there, and take care of your aiming issues as well.
>
> The front rack is a Surly Nice Rack, with a top platform and even a
> braze-on at center forward. The chief drawback consideration is that
> I'm accustomed to switching the light between modes while riding (can
> sometimes even get an oncoming car to lower their high beams by
> flashing them). If I ever get a serious lighting system with wires, I
> think I'd like to mount the headlight on the front rack, and wire a
> switch up to the handlebar.
>

More important than signaling oncoming cars to dim, I like to be able
to switch to attention-grabbing "SuperFlash" mode as I enter e.g.
trafficky situations where I may want to, um, grab attention, then
switch back to solid when I escape the gauntlet for darker
neighborhood streets.

<snip>

[Andre Jute]

On Saturday, December 29, 2012 8:40:32 AM UTC, Dan O wrote:
> Well, getting long for initial impressions. But anyway in a world
>
> where the next class of bike headlights seems to jump in price about
>
> 3x, these two ~cheap little lights together - at less than a hundred
>
> bucks total - produce a lot of light - or ~adequate light for longer
>
> runtime and a variety of modes separately or combined.

I enjoyed your test, Dan, but this last bit is misinformed. If you had a hub dynamo, for a hundred bucks you could get a BUMM Fly or Cyo at the front (or perhaps even a Phillips Saferide, which is a superior lamp) and a BUMM Toplight Line Plus at the rear, and then you would have what many consider the best lamps in the world, with no further cost for batteries. Here's my installation of specialist versions of the lamps I mention, complete with light-throw piccies: http://coolmainpress.com/BICYCLINGbuildingpedelec5.html Your installation would of course use a hub dynamo and the 6V version of these lamps.

Andre Jute

[Sir Ridesalot]

The advantage of Dan' lights is that they are easily transferred to different bikes.

Cheers

[Dan O]

> I enjoyed your test, Dan, but this last bit is misinformed. If you had a hub dynamo, for a hundred bucks you could get a BUMM Fly or Cyo at the front (or perhaps even a Phillips Saferide, which is a superior lamp) and a BUMM Toplight Line Plus at the rear, and then you would have what many consider the best lamps in the world, with no further cost for batteries. Here's my installation of specialist versions of the lamps I mention, complete with light-throw piccies: http://coolmainpress.com/BICYCLINGbuildingpedelec5.htmlYour installation would of course use a hub dynamo and the 6V version of these lamps.
>

As noted later, not going to debate merits of dynamo systems, but just
note that that *is* a *system* (and the key phrase is "If you had a
hub dynamo"). Also, a Ridesalot notes, these lights can readily go on
any bike (or *pair* of bikes), which was a big justification for
buying the PDW when I already had the PB.

If I last long enough, I suppose I'll inevitably get to try dynamo
lighting (hopefully something like SON / Inoled... er, what's this?
"New for 2013, Luxos IQ2 Headlights"... "... incorporates a handlebar
mounted switch... " - SWEET!)

[Lou Holtman]

Op 30-12-2012 7:22, Phil W Lee schreef:
> Sir Ridesalot <i_am_cyc...@yahoo.ca> considered Sat, 29 Dec 2012

> So is the Busch and Muller Ixon IQ, which runs on 4 x AA NiMH cells,
> and gives 5 hours on high (only necessary of unlit roads),

That is another marketing 'lie'. I have one and it runs max 2 hours on
high of which the last half an hour dangerously low for unlit roads.
Again I was disappointed in the battery life of a battery powered light.
Plenty of light but only for a short period of time that is the deal.
Charge before every ride, that sucks for me.

> 20 hours on
> low power (fine in town)

Also not true.

or any combination of those.
> Extra mounts are available so fitting to different bikes (or an
> alternative position like the fork crown) is a doddle, and with a ride
> & charge adapter cable you can even run it (and charge it) from a
> dynamo if you fit one later.
> It's the same emitter and optics as the Cyo.
> The mounts all have lateral adjustment as well as vertical.

That part is true.

Lou

[SMS]

Can't tell yet, but judging from the construction it should fare well.
The tail cap has two O ring gaskets so no water is likely to come in
that way. The front has one O ring gasket. The switch is sealed. The web
site simply says "splash proof" but that's probably because they don't
want to say "waterproof" and have people try to use it as a diving light.

The beam is excellent, with sufficient spill to illuminate off to the
sides. Lack of side illumination is a problem with a lot of the low end
bicycle lights which tend to concentrate their limited available output
directly onto the road in front of the bicycle. That's the big problem
with most dynamo powered lights.

I like the self-contained nature of these types of lights that lack
wires and external battery packs. The problem I have with most
commercial bicycle lights is the lack of lateral adjustment in the
mounts. While there are a lot of flashlight after-market mounts with
lateral adjustment, Many of them are not that great.

The ability to use AA cells (disposable or NiMH) as well as a higher
density Li-Ion battery is also a very good feature though if you're
using the Li-Ion and need to use disposables in a pinch you can't do
that unless you've brought along the AA carrier thingee.

[sms]

On 12/29/2012 5:59 PM, Sir Ridesalot wrote:

<snip>

> The advantage of Dan' lights is that they are easily transferred to different bikes.
>
> Cheers

Even though I have five hub dynamo wheels, not many people are going to
spend that the money even on one hub dynamo wheel.

It's too bad that bicycle pricing and marketing has dictated that what
would cost the manufacturer less than $5 to include when the bicycle is
built ends up costing 20-40x as much as an after-market product.

Of course the other issue with a dynamo light is that you can't remove
it and use it as a light to do repairs so you still need to carry along
a battery powered light anyway.

[sms]

On 12/29/2012 1:01 PM, Dan O wrote:

My mistake, I think you were talking about the PDW Cosmic Dreadnought,
not the PDW Spaceship.

[sms]

Peter White lists the run time on low as 13 hours, and high at 6 hours.
Users that have done actual tests have gotten around 5 hours of run
time, and not with the highest capacity NiMH batteries available. So if
you got only two hours then something was wrong with your batteries.

It's not a suitable light for commuting for other reasons unrelated to
the run time.

[James]

I'd rather the electronics were potted or have a conformal coating, and
the switch a sealed unit in itself. Wet batteries is of little concern.
Sealing is then of little concern, and in fact it would be nice to be
able to disassemble and clean any crud with water and a soft brush.
Seals don't last, and don't often work well enough. I'd rather
something that didn't rely on them.

> The beam is excellent, with sufficient spill to illuminate off to the
> sides. Lack of side illumination is a problem with a lot of the low end
> bicycle lights which tend to concentrate their limited available output
> directly onto the road in front of the bicycle. That's the big problem
> with most dynamo powered lights.

I do not agree. Nominal 3 Watts of electrical power from a dynamo is
plenty to produce more than adequate light output using LED lights,
including a good amount of side spill. Around 500 lm is quite doable.

--
JS

[SMS]

On 12/30/2012 1:28 PM, James wrote:

> I'd rather the electronics were potted or have a conformal coating, and
> the switch a sealed unit in itself. Wet batteries is of little concern.
> Sealing is then of little concern, and in fact it would be nice to be
> able to disassemble and clean any crud with water and a soft brush.
> Seals don't last, and don't often work well enough. I'd rather
> something that didn't rely on them.

Well those O rings are replaceable but they will last a very long time,
and seal better, if you apply a dab of O ring lube (buy from a pool
store). Don't use petroleum jelly.

> I do not agree. Nominal 3 Watts of electrical power from a dynamo is
> plenty to produce more than adequate light output using LED lights,
> including a good amount of side spill. Around 500 lm is quite doable.

If you're riding on well-lit streets a dynamo light is sufficient, and
in fact I do use one. I have five wheels with dynamo hubs. But the
dynamo output is inadequate in very dark conditions.

The other issue with most dynamo lights is that they lack a strobe mode
which is extremely desirable for daytime use.

[James]

On 31/12/12 09:13, SMS wrote:
> On 12/30/2012 1:28 PM, James wrote:
>
>> I'd rather the electronics were potted or have a conformal coating, and
>> the switch a sealed unit in itself. Wet batteries is of little concern.
>> Sealing is then of little concern, and in fact it would be nice to be
>> able to disassemble and clean any crud with water and a soft brush.
>> Seals don't last, and don't often work well enough. I'd rather
>> something that didn't rely on them.
>
> Well those O rings are replaceable but they will last a very long time,
> and seal better, if you apply a dab of O ring lube (buy from a pool
> store). Don't use petroleum jelly.
>
>> I do not agree. Nominal 3 Watts of electrical power from a dynamo is
>> plenty to produce more than adequate light output using LED lights,
>> including a good amount of side spill. Around 500 lm is quite doable.
>
> If you're riding on well-lit streets a dynamo light is sufficient, and
> in fact I do use one. I have five wheels with dynamo hubs. But the
> dynamo output is inadequate in very dark conditions.

I have no problem riding on unlit roads with my dynamo lights.

There is enough electrical power available to produce adequate light.

Your light is obviously not appropriate.

It is a poorly aimed accusation to say the dynamo is somehow inadequate.

I don't use a dynamo hub. Not all dynamos are equal, just as not all
lights are equal.

> The other issue with most dynamo lights is that they lack a strobe mode
> which is extremely desirable for daytime use.

There is usually no need for strobe lights in daylight hours. I always
use a battery powered red LED blinky at the rear anyway, but only turn
it on when visibility is poor - like in early morning fog or rain.

--
JS.

[sms]

On 12/30/2012 2:33 PM, James wrote:
> On 31/12/12 09:13, SMS wrote:
>> On 12/30/2012 1:28 PM, James wrote:
>>
>>> I'd rather the electronics were potted or have a conformal coating, and
>>> the switch a sealed unit in itself. Wet batteries is of little concern.
>>> Sealing is then of little concern, and in fact it would be nice to be
>>> able to disassemble and clean any crud with water and a soft brush.
>>> Seals don't last, and don't often work well enough. I'd rather
>>> something that didn't rely on them.
>>
>> Well those O rings are replaceable but they will last a very long time,
>> and seal better, if you apply a dab of O ring lube (buy from a pool
>> store). Don't use petroleum jelly.
>>
>>> I do not agree. Nominal 3 Watts of electrical power from a dynamo is
>>> plenty to produce more than adequate light output using LED lights,
>>> including a good amount of side spill. Around 500 lm is quite doable.
>>
>> If you're riding on well-lit streets a dynamo light is sufficient, and
>> in fact I do use one. I have five wheels with dynamo hubs. But the
>> dynamo output is inadequate in very dark conditions.
>
> I have no problem riding on unlit roads with my dynamo lights.
>
> There is enough electrical power available to produce adequate light.
>
> Your light is obviously not appropriate.
>
> It is a poorly aimed accusation to say the dynamo is somehow inadequate.

A 6V/3W dynamo is fine if you're not depending on your lights as the
only source of light. On dark roads, where you need to see not only in
front of you, but off to the sides, and when you're riding at moderately
fast speeds (10+ MPH) a dynamo can't provide sufficient power no matter
how good the lights are. Well there is one exception, and that's if the
dynamo is charging a battery powered light all the time, not just at
night. That's probably the best solution, banking power during the day
by having the dynamo engaged so at night you have sufficient power for
your lights.

> I don't use a dynamo hub. Not all dynamos are equal, just as not all
> lights are equal.

That's true. The 12V/6W dynamos can supply sufficient power and those
are not hub dynamos.

> There is usually no need for strobe lights in daylight hours.

In the U.S. there is a need.

[Lou Holtman]

There is nothing wrong with my batteries. Did a test tonight. Fully
charged, original charger, original batteries with only a few charge
cycles. At room temperature of 21 C on high after three hours the
amount of light sank to a pitiful level, hardly enough for a to be seen
light on well lit streets. I don't believe what Peter White list or
what other people say if I have my own observations. 5-7 hours on high?
No way.


--

Lou

[datakoll]

KNOW OF Powerstream ?

http://www.powerstream.com/dcdc.htm

[datakoll]

the Euro batts sat too loong on the shelf.

[AMuzi]

On 12/30/2012 5:45 PM, datakoll wrote:
> KNOW OF Powerstream ?
>
> http://www.powerstream.com/dcdc.htm
>

Made in Wisconsin:

http://www.youtube.com/watch?v=qnHrDoIRoQQ

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

[Frank White]

For $15 you can get a Rayovac Indestructible that will beat both PB and PDW in both output and runtime. The rear switch is cheap and gimpy, but otherwise these lights are pretty damn tough.

http://www.homedepot.com/h_d1/N-5yc1v/R-202968168/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=rayovac&storeId=10051#.UODeqO-_Nbk

http://www.candlepowerforums.com/vb/showthread.php?330915-Torture-test-Varta-Rayovac-2AA-Indestructible-*FREEZE-TEST-ADDED*

http://www.youtube.com/watch?v=dIEo8USPokg

For $37 dollars you can get a Fenix E25. This is a tactical level light at a crap light price and will actually outthrow and outrun tactical lights that cost twice as much.

http://www.fenixlight.com/viewproduct.asp?id=172

http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?productId=203631780&storeId=10051&langId=-1&catalogId=10053&ci_sku=203631780&ci_kw={keyword}&kwd={keyword}&cm_mmc=shopping-_-googleads-_-pla-_-203631780&ci_gpa=pla#.UODenO-_Nbk

[James]

I do not agree.

>> I don't use a dynamo hub. Not all dynamos are equal, just as not all
>> lights are equal.
>
> That's true. The 12V/6W dynamos can supply sufficient power and those
> are not hub dynamos.

My dynamo is rated 6V/3W.

See next post.

--
JS.

[James]

You talk about switching to lights with claimed output of 800 lumens,
claim they only produce 200 lumen on high, and say this is very often
more than you need.

How then is the 3W output from a dynamo that is capable of producing at
least 500 lumens (being conservative as CREE has announced a 200
lumen/Watt LED, the MK-R XLamp) somehow worse?

http://www.cree.com/news-and-events/cree-news/press-releases/2012/december/~/link.aspx?_id=6F4EBE1D3AFF4CF69B610985C8AF0C18&_z=z

The light you're talking about looks to be a torch, with no beam shaping
for bicycle use. I think you need to rethink your solution. Your logic
is misguided.

http://product.madeinchina.com/UltraFire-SH-3AA-Cree-XM-L-T6-800LM-5-Mode-Memory_13601074.shtml

--
JS.

[Frank Krygowski]

On Dec 30, 1:04 pm, sms <scharf.ste...@geemail.com> wrote:
>
> Of course the other issue with a dynamo light is that you can't remove
> it and use it as a light to do repairs so you still need to carry along
> a battery powered light anyway.

I've got a coin-cell LED keychain light in my handlebar bag, and
another that's always in my pocket, should I need them. However, so
far I've never had to fix anything at night when I couldn't find a
street lamp nearby.

- Frank Krygowski

[Sir Ridesalot]

No too many street lights along this area's rail trails or county roads.

Cheers

[Frank Krygowski]

On Dec 30, 5:13 pm, SMS <scharf.ste...@geemail.com> wrote:
>
>
> If you're riding on well-lit streets a dynamo light is sufficient, and
> in fact I do use one. I have five wheels with dynamo hubs.

Progress! Thus ends years of Scharf claiming they were totally
inadequate!

> But the dynamo output is inadequate in very dark conditions.

... like Paris-Brest-Paris, where they are very popular? Looks like
some study time is still in order!

> The other issue with most dynamo lights is that they lack a strobe mode
> which is extremely desirable for daytime use.

:-) How soon till SMS praises Mandatory Daylight Strobe laws? For
safety, of course!

- Frank Krygowski

[Frank Krygowski]

On Dec 30, 6:06 pm, sms <scharf.ste...@geemail.com> wrote:
>
> A 6V/3W dynamo is fine if you're not depending on your lights as the
> only source of light. On dark roads, where you need to see not only in
> front of you, but off to the sides, and when you're riding at moderately
> fast speeds (10+ MPH) a dynamo can't provide sufficient power no matter
> how good the lights are.

I take back my prior post. Any progress in SMS's thinking has been
negligible.

- Frank Krygowski

[Frank Krygowski]

Then carry a coin cell LED light. Maybe $3, negligible weight.

- Frank Krygowski

[SMS]

On 12/30/2012 4:46 PM, Frank White wrote:
> For $15 you can get a Rayovac Indestructible that will beat both PB and PDW in both output and runtime. The rear switch is cheap and gimpy, but otherwise these lights are pretty damn tough.
>
> http://www.homedepot.com/h_d1/N-5yc1v/R-202968168/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=rayovac&storeId=10051#.UODeqO-_Nbk
>
> http://www.candlepowerforums.com/vb/showthread.php?330915-Torture-test-Varta-Rayovac-2AA-Indestructible-*FREEZE-TEST-ADDED*
>
> http://www.youtube.com/watch?v=dIEo8USPokg

There's no strobe on this plus it suffers from the same problem that
most AA flashlights; they try to keep it slim and as a result the head,
and hence the reflector, is quite small which is inefficient.

There are a few AA lights with a large head and reflector, but not a
great many.

> For $37 dollars you can get a Fenix E25. This is a tactical level light at a crap light price and will actually outthrow and outrun tactical lights that cost twice as much.
>
> http://www.fenixlight.com/viewproduct.asp?id=172

No strobe on that either. Forget it.

[datakoll]

Home Depot ? there's crossover sometimes illuminating the or an extra charge for a hobby group's special needs, one need shellling out more dough than an akuminum siding guy. Infacto last one I saw was a light whose front half appeared as a cyclelight. At hD the light had a back half light with red strobe....and half price from the cycle offering.

HD's tool bags are cycle rack appro.

The glue section.

[Steveroberts]

Dan O;2319945 Wrote:
> Around the cusp of the dark solstice...
>
> It *was* going to be a shootout: Planet Bike Blaze 2-watt vs.
> Portland Design Works Cosmic Dreadnaught 110 - head-to-head, side-by-
> side on opposite sides of the handlebar stem.
>
> First impression (of the combo w/ Dreadnaught): These two lights -
> with many remarkable similarities and differences - got together and
> *complemented* each other.
>
> We know how I have used and generally like PB Blaze headlights for
> what they are - except for that *enormously* disillusioning
> (disilluminating?) rain experience:
>
> http://groups.google.com/group/rec.bicycles.tech/msg/9a052e6335b836c8
>
> So when I saw the PDW headlight, purportedly "Built to withstand
> rain... " and seemingly priced to compete with the 2-watt PB Blaze, my
> interest was piqued. Unfortunately, PDW did *not* see fit to sponsor
> me a light; but when I saw it on Amazon for thirty-some bucks and free
> super saver shipping, I sprung for it (so now they'll get the totally
> unvarnished review).
>
> As noted, the similarities are remarkable: Compact LED self-contained
> 2xAA "folded penlights", either can snap on to the other's bracket.
> (The PDW guys are former PB guys.) MSRP about exactly the same.
> High, low, and blinking modes.
>
> For such similar products, the differences are remarkable. PB button
> switches low, high, blinkety-flash, PDW high, low, blink-blink. PB
> blinkety-flash mode is crazy attention-getting (SuperFlash (TM), PDW
> goes blink, blink, blink. (Well, those are piddly differences, but
> wait... )
>
> PB has a nice (I think) round, far reaching spot with useful
> attenuated spill (?) spread outside the spot. PDW has a more squarish/
> rectangular beam and gobs of side spill through two side windows much
> bigger than the PB side windows (which I've kind of obscured anyway
> with my Saran wrap waterproofing mod). PDW spills relatively bright
> light onto the handlebar, the fork crown, water bottles, my legs...
> kind of distracting (bright enough that looking down can cause my eyes
> to need to re-ajust when looking back up). Probably better for "being
> seen" from off center, I guess.

>
> The PDW produces pretty good light to see by - even on low. So did
> the PB. The PDW actually looks brighter, but I know this can be very
> much a peak battery thing, and all my NiMH's are pretty old and of
> suspect capacity, so not sure yet. But... the two of them together
> both on high are pretty awesome (complementary).
>

> Must break in here with a huge difference: The PB is a snap to change
> batteries (well, used to be a snap before the snap catch wore smooth
> and doesn't "snap" anymore - but it doesn't fall open either, so... )
> Anyway, the PB is easy to change batteries, twist the head and it pops
> off to dump spent and drop fresh batteries, twist and go. The PDW has
> a friggin' *screw* holding the fiddly cover, over a more typical lay-
> in battery tray. This would be understandable if it weren't for the
> fact that the PB battery compartment never had a problem with
> wetness. (Must be a patent thing.)
>
> In light of (ha-ha) the huge difference in battery change convenience,
> and the bracket slide-on compatibility, it occurred to me that the PB
> light could be a primary daily (nightly) headlight, with the even more
> compact (barely bigger than a spare pair of batteries) PDW stowed in
> the messenger bag as backup - maybe with some sort of batteries with
> less tendency self-discharge when installed.

>
> Well, getting long for initial impressions. But anyway in a world
> where the next class of bike headlights seems to jump in price about
> 3x, these two ~cheap little lights together - at less than a hundred
> bucks total - produce a lot of light - or ~adequate light for longer
> runtime and a variety of modes separately or combined.

Do you have any pics of these good looking led lights?




--
Steveroberts

[Dan O]

On Dec 30, 9:16 pm, Steveroberts

Do you mean the output? I may try. Though my photo experience tells
me it's hard to make it real. Hveck, even my eyes aren't anyone
else's.

(Pics of the hardware are on each of the manufacturer's web sites -
Portland Design Works Cosmic Dreadnaught 110 and Planet Bike Blaze 2-
watt)

I will add here since I've lost track of where I was, that I switched
batteries (after ~re-charging) one to the other, and very first
impression then (just in the garage) is that the PB brightness
benefitted and the PDW brightness suffered (no more swamping). So, as
I suspected, battery differences may have been a significant factor in
earlier brightness comparison.

Am thinking of trying to mount the PDW down on the front rack to try
and lose some of that annoying local spill onto the bike and myself.

(Must admit, I'm all hung up on wanting the SON/Luxus U system w/
handlebar switch now.)

[SMS]

On 12/29/2012 12:40 AM, Dan O wrote:

<snip>

> Well, getting long for initial impressions. But anyway in a world
> where the next class of bike headlights seems to jump in price about
> 3x, these two ~cheap little lights together - at less than a hundred
> bucks total - produce a lot of light - or ~adequate light for longer
> runtime and a variety of modes separately or combined.

I do like that you included "to see by" in your subject line.

I was at Interbike in September and since I'm interested in lighting I
talked to a lot of the lighting companies. It seems like "to see by" LED
lights are a market segment where a lot of companies think they are
going to to make a killing. They don't understand that the market for
$150+ bicycle lights is pretty small. Even the market for $40 bicycle
lights isn't big enough to support all the manufacturers.

A couple of companies appear to be interested in the entry level market.
Magicshine, often deprecated because they sell a lot of volume through
DealExtreme, was at the show and they are making a play to sell through
the LBS. I don't know how this will work out for them. The LBS might not
be interested in selling $85 Magicshine lights, even for $125, versus
$259 Dinotte lights which probably have better margins. It's also
possible that entry level stops at $40 and that the customer willing to
spend more than that is just as willing to spend $259 as they are to
spend $85, or they may be willing to spend even more and buy a new wheel
with a dynamo along with a high-end dynamo light. Then you have the
customers that thing $20 for front and rear lights from Walmart is
already too expensive.

1. Run time is not a huge concern. People are so used to charging stuff
every night that they don't care about charging one more thing. So huge
batter packs with very long run times aren't important. A run time long
enough for a couple of commutes per charge is sufficient for front lights.

2. Consumer resistance to proprietary Li-Ion batteries. Despite the
major technical advantages to Li-Ion versus NiMH, consumers don't like
the expense, the proprietary chargers, and the longevity of Li-Ion
battery packs. They've gotten used to Li-Ion batteries wearing out and
needing replacement on their phones, iPods, cameras, and laptops. They
also want to be able to carry or buy spare batteries in a pinch. So
despite the lower energy density, AA batteries are preferred by most
consumers. You used to see something similar in the digital camera
market though now there are very very few digital cameras powered by AA
batteries.

3. A front strobe is an absolute necessity. Almost no one will buy a
front light without a daytime strobe. It's the equivalent of DRLs for cars.

4. External battery packs are not desirable. A lot of riders don't like
the extra pieces, the size, or the hassle. Since often the lights can't
be left on the bicycle while parked, they want something more portable.
So whether it's a flashlight or purpose built-bicycle light, the
batteries should be with the light, not connected by a cable to a
battery pack. What _would_ be desirable is the cell phone model of
charging the batteries without removing them from the device.
Unfortunately this means putting connector holes into the body of the
light which would affect the weatherproofing. You can already buy decent
Li-Ion flashlights that have an internal charger and a charging port
<http://www.amazon.com/dp/B004VPDTOO>.

5. Dynamo lights will be used only when the dynamo hub wheel was sold
with the bicycle. So a few Joe Breeze and REI models will be the
majority of dynamo lights. No one wants a tire driven dynamo. A few hard
core commuters might add a dynamo wheel to their existing bicycles but
not enough to support more than a specialty retailer like Peter White
who is not giving up a large part of his margins to QBP or J&B. Yeah,
there will be a few very special shops like Yellow Jersey and Harris
that carry these products, but it's a very niche market.

6. The lighting companies see LED flashlights as their competition.
There were numerous products at the show for mounting AA or C battery
flashlights to handlebars, including the ubiquitous TwoFish Cyclopblock�
<http://www.lighthound.com/Twofish-Cyclopblock-Flashlight-Bicycle-Mount_p_2251.html>.

[Sir Ridesalot]

I don't need to carry an extra light since my battery lights light up a two lane road to beyond the shoulders and they are bright enough for me to ride at 50+ kms/hr. I can easily remove the light from the mount and use it with a head band mount in order to see to do any needed repair as I did late one very dark moonless night about 10 kms from town when I changed a punctured tube. Plus with my very good battery lights I do not have to worry about carrying and/or forgetting a smaller light.

Cheers

[sms]

On 12/31/2012 7:31 AM, Sir Ridesalot wrote:

<snip>

> I don't need to carry an extra light since my battery lights light up a two lane road to beyond the shoulders and they are bright enough for me to ride at 50+ kms/hr. I can easily remove the light from the mount and use it with a head band mount in order to see to do any needed repair as I did late one very dark moonless night about 10 kms from town when I changed a punctured tube. Plus with my very good battery lights I do not have to worry about carrying and/or forgetting a smaller light.

A coin cell flashlight isn't going to provide enough light even for
repairs. The best option for a small size repair flashlight is one
that's powered by a single CR123A battery, i.e.
<http://dx.com/p/romisen-cree-rc-n3-3-mode-led-flashlight-1xcr123a-2xaa-9070>.

You do point out a major issue and that's outrunning your lights. Dynamo
lights were never intended for high speed commuting like you often see
in the U.S.. It's very different than the slow speed commuting you see
in places like the Netherlands or in China. The other issue that you
mention that's very important is being able to light up not just the
patch of road directly in front of you, but off to the shoulders as well.

There's a peak power to dynamos regardless of the speed, and until the
advent of LED lights you'd burn out the bulb unless you had some sort of
voltage regulator, which of course kept the light output at a fixed
limit. With LED lamps things have improved somewhat since as long as the
LED lamp has sufficient thermal dissipation you can run it at higher
voltages without incident.

[Dan O]

A little tiny dedicated worklight is apt to go dead right when you
need it most (a bike headlight will be maintained charged), the coin
cell LED lights I've ever seen all require to hold the switch down to
activate, and I've never used one beyond trying it to see if it works
and then I don't know where any of them went after that [I have no use
for them]. Heck, my Kryptonite U-lock key has a little flashlight
built in).

[Lou Holtman]

Op 31-12-2012 18:17, sms schreef:

> On 12/31/2012 7:31 AM, Sir Ridesalot wrote:
>
> <snip>
>
>> I don't need to carry an extra light since my battery lights light up
>> a two lane road to beyond the shoulders and they are bright enough for
>> me to ride at 50+ kms/hr. I can easily remove the light from the mount
>> and use it with a head band mount in order to see to do any needed
>> repair as I did late one very dark moonless night about 10 kms from
>> town when I changed a punctured tube. Plus with my very good battery
>> lights I do not have to worry about carrying and/or forgetting a
>> smaller light.
>
> A coin cell flashlight isn't going to provide enough light even for
> repairs. The best option for a small size repair flashlight is one
> that's powered by a single CR123A battery, i.e.
> <http://dx.com/p/romisen-cree-rc-n3-3-mode-led-flashlight-1xcr123a-2xaa-9070>.
>
>
> You do point out a major issue and that's outrunning your lights. Dynamo
> lights were never intended for high speed commuting like you often see
> in the U.S.. It's very different than the slow speed commuting you see
> in places like the Netherlands or in China. The other issue that you
> mention that's very important is being able to light up not just the
> patch of road directly in front of you, but off to the shoulders as well.

The brightest light I have is a dynamo powered light. If you want lights
for high speed commuting you can go the dynamo route. It doesn't get
better than this:

<https://picasaweb.google.com/101076538433373858645/DynohubLightSystem?authkey=Gv1sRgCP6Iu6qy_tbU9gE#5657107301581393666>

This light is better than all the battery powered lights I use(d).

For slow speed commuting on well lit streets you can get away with
cheaper front lights.


Lou

[AMuzi]

Tactical light? So where's the Pikatinny mount?

[Dan O]

That's how it is for me. I get about two round trips out of a pair of
charged AA NiMH's, and the charger is sitting by the garage door in
regular use for a variety of household items (anyone else have a bunch
of Nintendo WII remote controls?) with charged cells in a tray on one
side and to-be-charged in a tray on the other.

> 3. A front strobe is an absolute necessity. Almost no one will buy a
> front light without a daytime strobe. It's the equivalent of DRLs for cars.
>

I really like being able to dynamically activate an attention-getting
change in presentation when entering situations that call for it, and
yeah - the very low power consumption of LED's in flashing mode makes
them worth running always on in city traffic.

> 4. External battery packs are not desirable. A lot of riders don't like
> the extra pieces, the size, or the hassle. Since often the lights can't
> be left on the bicycle while parked, they want something more portable.
> So whether it's a flashlight or purpose built-bicycle light, the
> batteries should be with the light, not connected by a cable to a
> battery pack. What _would_ be desirable is the cell phone model of
> charging the batteries without removing them from the device.
> Unfortunately this means putting connector holes into the body of the
> light which would affect the weatherproofing. You can already buy decent
> Li-Ion flashlights that have an internal charger and a charging port
> <http://www.amazon.com/dp/B004VPDTOO>.
>

That would be a nice feature - like plugging in the electric car for
the next day's commute.

> 5. Dynamo lights will be used only when the dynamo hub wheel was sold
> with the bicycle. So a few Joe Breeze and REI models will be the
> majority of dynamo lights. No one wants a tire driven dynamo. A few hard
> core commuters might add a dynamo wheel to their existing bicycles but
> not enough to support more than a specialty retailer like Peter White
> who is not giving up a large part of his margins to QBP or J&B. Yeah,
> there will be a few very special shops like Yellow Jersey and Harris
> that carry these products, but it's a very niche market.
>

I'm definitely right in PW's narrow target demographic - except for
the cash flow / budget.

> 6. The lighting companies see LED flashlights as their competition.
> There were numerous products at the show for mounting AA or C battery
> flashlights to handlebars, including the ubiquitous TwoFish Cyclopblock�

> <http://www.lighthound.com/Twofish-Cyclopblock-Flashlight-Bicycle-Moun...>.

Whatever gets decent lighting on more bikes (isn't that Frank's pet
beef: Drunken wrong way no lights etc.?) also enables more bikes on
the road any time of night or day (one less excuse to take the car).

[sms]

On 12/31/2012 9:42 AM, Lou Holtman wrote:

> The brightest light I have is a dynamo powered light.

That's too bad. I can advise you on where to buy better lights.

[sms]

On 12/31/2012 9:41 AM, Dan O wrote:

> A little tiny dedicated worklight is apt to go dead right when you
> need it most (a bike headlight will be maintained charged), the coin
> cell LED lights I've ever seen all require to hold the switch down to
> activate, and I've never used one beyond trying it to see if it works
> and then I don't know where any of them went after that [I have no use
> for them]. Heck, my Kryptonite U-lock key has a little flashlight
> built in).

That's why a CR123A powered flashlight would be a good companion light
to a dynamo light. The CR123A battery has a very long shelf life yet the
energy density is very high. It can even be used as a primary bicycle
light if there are problems with the dynamo light. Dynamo lights with
all the wires running around the bike are prone to occasional problems,
though at least with LED dynamo lights the biggest problem, burned out
bulbs, has disappeared for the most part.

[Frank Krygowski]

That's fine, Sir. I don't worry about carrying a keychain light
either; it's just there in my handlebar bag. Since I use generator
lights, I also don't worry about charging or replacing batteries, nor
about battery run times. My bike lights are like my car's lights;
they're just there, and they just work.

I mentioned keychain lights only as the ultra-simple solution to the
overstated "how do I fix a flat with a generator light" problem.
(Although, come to think of it, half my generator lights have
standlights anyway.) Advantages, disadvantages, etc. Ride what you
like.

- Frank Krygowski

[Frank Krygowski]

On Dec 31, 12:17 pm, sms <scharf.ste...@geemail.com>, our font of

misinformation, wrote:
>
>
> A coin cell flashlight isn't going to provide enough light even for
> repairs.

Really? Sound like you haven't tried one.

> You do point out a major issue and that's outrunning your lights. Dynamo
> lights were never intended for high speed commuting like you often see
> in the U.S.. It's very different than the slow speed commuting you see
> in places like the Netherlands or in China.

And yet competitors commonly use them to ride the 1200 km round trip
competition from Paris to Brest and back, every four years. What do
they know that SMS does not?

> The other issue that you
> mention that's very important is being able to light up not just the
> patch of road directly in front of you, but off to the shoulders as well.

Says the man who advocates a spot beam instead of optics designed for
the road, as with all other road vehicles. Again, he has apparently
never tried a bike headlight designed to German standards.

> There's a peak power to dynamos regardless of the speed, and until the
> advent of LED lights you'd burn out the bulb unless you had some sort of
> voltage regulator, which of course kept the light output at a fixed
> limit.

All this is discussing a problem which was solved by about 1980.

> With LED lamps things have improved somewhat since as long as the
> LED lamp has sufficient thermal dissipation you can run it at higher
> voltages without incident.

If SMS would ever try a bike headlight properly designed to German
road standards, he would be far more informed.

However, as with the hub generators that he's finally tried, he'll
probably still try to save face by finding some imaginary shortcoming.

I'm not saying people shouldn't use battery lights, if that's what
they want. But people really should be up to date and honest in their
technical statements.

- Frank Krygowski

[Frank Krygowski]

On Dec 31, 12:41 pm, Dan O <danover...@gmail.com> wrote:
>
> A little tiny dedicated worklight is apt to go dead right when you
> need it most (a bike headlight will be maintained charged), the coin
> cell LED lights I've ever seen all require to hold the switch down to
> activate, and I've never used one beyond trying it to see if it works
> and then I don't know where any of them went after that [I have no use
> for them].  Heck, my Kryptonite U-lock key has a little flashlight
> built in).

I bought my first one of these in about 2001, from an outdoor store as
I was on day one of a week-long bike tour to visit my daughter at her
college. They had one model that was on only when you squeezed it,
another with a stay-on switch. I paid an extra $1 for the latter.

I used it for reading in the tent at night, finding my campsite after
trips to campground showers & rest rooms, etc. The battery lasted not
only through that trip, but probably a year beyond, although most of
that time it just sat in my pocket.

As with a mini-Leatherman, I find it worth carrying all the time.
I've recently used it to read notes on a breaker box, look at a map at
night, etc.

The only problem has been occasionally forgetting to take one out of
my pocket before the pants get laundered. Sometimes they survive,
sometimes they don't.

- Frank Krygowski

[Frank Krygowski]

On Dec 31, 1:17 pm, sms <scharf.ste...@geemail.com> wrote:
>
> That's why a CR123A powered flashlight would be a good companion light
> to a dynamo light. The CR123A battery has a very long shelf life yet the
> energy density is very high. It can even be used as a primary bicycle
> light if there are problems with the dynamo light. Dynamo lights with
> all the wires running around the bike are prone to occasional problems,
> though at least with LED dynamo lights the biggest problem, burned out
> bulbs, has disappeared for the most part.

For many years, I led several night rides per year for our bike club.
About four of us used generator lights. None ever had a problem.
OTOH, it was actually rare to complete a ride without some battery
light failing - everything from "Darn, this battery lasted way longer
last time I recharged it" to "I was sure these disposable batteries
were new" to "Wait! My headlight came apart when I hit that pothole!"
to "Aaugh! My flashlight slipped into my spokes! I think I broke my
rib!"

Snagging a wire is possible, I suppose, just as it is with cyclometer
wires. Maybe someday it will happen to me. Maybe. Someday.

The only frustrating problem I recall with my generator systems was on
my commuting bike back in its halogen headlight days. The light would
flicker off for a fraction of a second or so from time to time, when I
was on a rough road. I kept looking for, and not finding, a bad
connection in the system.

Finally I found it. The headlamp's brass contact for the bulb's
center terminal had worn the bulb's solder contact flat, and was
barely contacting it. Obviously, the bulb was far from new. I flexed
the headlamp's contact outward a bit, and added another drop of solder
to the headlamp for good measure. No further problems.

- Frank Krygowski

[russell...@yahoo.com]

On Sunday, December 30, 2012 5:06:58 PM UTC-6, sms wrote:
> On 12/30/2012 2:33 PM, James wrote:
>
> > On 31/12/12 09:13, SMS wrote:
>
> >> On 12/30/2012 1:28 PM, James wrote:
>
> >>
>
> >>> I'd rather the electronics were potted or have a conformal coating, and
>
> >>> the switch a sealed unit in itself. Wet batteries is of little concern.
>
> >>> Sealing is then of little concern, and in fact it would be nice to be
>
> >>> able to disassemble and clean any crud with water and a soft brush.
>
> >>> Seals don't last, and don't often work well enough. I'd rather
>
> >>> something that didn't rely on them.
>
> >>
>
> >> Well those O rings are replaceable but they will last a very long time,
>
> >> and seal better, if you apply a dab of O ring lube (buy from a pool
>
> >> store). Don't use petroleum jelly.
>
> >>
>
> >>> I do not agree. Nominal 3 Watts of electrical power from a dynamo is
>
> >>> plenty to produce more than adequate light output using LED lights,
>
> >>> including a good amount of side spill. Around 500 lm is quite doable.
>
> >>
>

> >> If you're riding on well-lit streets a dynamo light is sufficient, and
>

> >> in fact I do use one. I have five wheels with dynamo hubs. But the

>
> >> dynamo output is inadequate in very dark conditions.
>
> >
>

> > I have no problem riding on unlit roads with my dynamo lights.
>
> >
>
> > There is enough electrical power available to produce adequate light.
>
> >
>
> > Your light is obviously not appropriate.
>
> >
>
> > It is a poorly aimed accusation to say the dynamo is somehow inadequate.
>
>
>

> A 6V/3W dynamo is fine if you're not depending on your lights as the
>
> only source of light. On dark roads, where you need to see not only in
>
> front of you, but off to the sides, and when you're riding at moderately
>
> fast speeds (10+ MPH) a dynamo can't provide sufficient power no matter
>

> how good the lights are.


Odd. I find my Busch Mueller IQ Cyo lights perfectly good in the dark. Driven by a Shimano DH-3N70 generator hub. On completely dark roads they work best. With street lights and other light around they are not quite as good. The lights provide plenty of side spill to see the edges of the road plus far in front of you. Kind of an odd thing, but the darker it is, the less light you need to see. A small light works perfectly in the pitch dark. When you have lots of ambient light, you need a much stronger headlight.

I used this Shimano DH-3N70 generator hub on PBP in 2007. It had Schmidt halogen lights then. Rode 760 miles in August 2007. Many miles in the rain and night. Now have the B&M IQ Cyo LED lights. Two lights driven by the generator.




> > There is usually no need for strobe lights in daylight hours.
>
>
> In the U.S. there is a need.

Thankfully I do not ride in the daylight with a strobe light. No need. It would have to be an extremely powerful strobe to be seen in the daylight. Sunlight kind of blinds the strobe effect. Blinking rear red lights are also not very visible in the daylight. At night yes. I do advocate wearing bright cycling clothes when riding. Yellow, orange are great colors for cyclig clothes.

[Jay Beattie]

What has kept me from taking the plunge is the cost and inconvenience
(wiring and rebuilding my front disc). I'm not riding the PBP or
spending more than one to two hours riding after dark, and I need a
bright light in the rain and with all the inner-city light noise. To
approximate my current 750 lumen battery set up with a high quality
dyno (Schmidt/Supernova), I'm looking at $600 -- plus wheel components
(rims and spokes), wires, connectors and my time. I like the idea of
not having to remember to re-charge or having to throw away batteries,
but that's a lot of dough for a lighting system.

-- Jay Beattie.

[Frank Krygowski]

On Dec 31, 5:35 pm, Jay Beattie <jbeat...@lindsayhart.com> wrote:
>
> What has kept me from taking the plunge is the cost and inconvenience
> (wiring and rebuilding my front disc). I'm not riding the PBP or
> spending more than one to two hours riding after dark, and I need a
> bright light in the rain and with all the inner-city light noise. To
> approximate my current 750 lumen battery set up with a high quality
> dyno (Schmidt/Supernova), I'm looking at $600 -- plus wheel components
> (rims and spokes), wires, connectors and my time.  I like the idea of
> not having to remember to re-charge or having to throw away batteries,
> but that's a lot of dough for a lighting system.

Well, contrary to what the Minister of Lighting Misinformation may
claim, hub generators are not the only generator game in town. I've
got either bottle generators or roller (bottom bracket) generators on
five bikes (i.e. my wife's and mine). They work fine for us, and for
many other people.

Now your winter riding sounds much more extreme than most people's,
and that's where a hub unit would be better. But to get a taste of
things, you could mount a more conventional generator during the
summer and see how you like it. It would have a little less
efficiency and (depending on model) might occasionally slip in the
rain, but it would be a decent introduction to the technology.

Regarding hub generators: I actually bought my Shimano hub unit at
CityBikes on Ankeny. They tend to be into practical things like
generators, and might give you some good advice. They might even have
a used bottle or roller model for sale. But if so, do a little
research to make sure you got a decent one.

O.T.: When I bought the hub generator - a weird cylindrical device
with wires sticking out of it - I said to the girl behind the counter
at CityBikes, "I wonder if the TSA will let me take this home in my
suitcase." She asked where I was flying to, and I said "I live in
Ohio."

She immediately got a wistful look on her face and said "Ohio! Oh, my
brother is going to college in Ohio and he says it's just _beautiful_,
all lush and green! I've wanted to go to Ohio ever since!" All I
could say was "Yep, I love it. It's great for bicycling."

- Frank Krygowski

[Frank Krygowski]

On Dec 31, 10:01 am, SMS <scharf.ste...@geemail.com> wrote:
>
> 3. A front strobe is an absolute necessity. Almost no one will buy a
> front light without a daytime strobe. It's the equivalent of DRLs for cars.

How many readers think a front strobe is an absolute necessity for
daylight riding? Anyone besides SMS?

- Frank Krygowski

[SMS]

On 12/31/2012 2:35 PM, Jay Beattie wrote:

> What has kept me from taking the plunge is the cost and inconvenience
> (wiring and rebuilding my front disc). I'm not riding the PBP or
> spending more than one to two hours riding after dark, and I need a
> bright light in the rain and with all the inner-city light noise. To
> approximate my current 750 lumen battery set up with a high quality
> dyno (Schmidt/Supernova), I'm looking at $600 -- plus wheel components
> (rims and spokes), wires, connectors and my time. I like the idea of
> not having to remember to re-charge or having to throw away batteries,
> but that's a lot of dough for a lighting system.

When people learn how much a top-end dynamo system costs they recoil in
horror.

That said, on the bicycles I have with hub dynamos I'm using less than
the top end stuff. Between the dynamo wheel and the 4W Cree LED lamp I
spent about $100 per bicycle for dynamo lighting. It's adequate for
around town. You'll never get the current levels with a dynamo that you
get with Li-Ion or NiMH batteries though.

What I'd like to see is a good rechargeable headlight that charges from
a hub dynamo on a continuous basis, even in the day time, so external
recharging is rarely needed. Shouldn't be too hard to do, but I think
there's just no market for an even more expensive system.

[Joe Riel]

Possibly he meant a necessity from a marketing point of view, that is,
if the manufacturer doesn't offer it, the sell will be lost. I've seen
the occasional rider with a strobe on the front; under some conditions
it increases the visibility but I'm not convinced dramatically. Hardly
a necessity from this cyclist's point of view.

--
Joe Riel

[David Scheidt]

Frank Krygowski <frkr...@gmail.com> wrote:

:On Dec 31, 5:35 pm, Jay Beattie <jbeat...@lindsayhart.com> wrote:
:>
:> What has kept me from taking the plunge is the cost and inconvenience
:> (wiring and rebuilding my front disc). I'm not riding the PBP or
:> spending more than one to two hours riding after dark, and I need a
:> bright light in the rain and with all the inner-city light noise. To
:> approximate my current 750 lumen battery set up with a high quality
:> dyno (Schmidt/Supernova), I'm looking at $600 -- plus wheel components
:> (rims and spokes), wires, connectors and my time.  I like the idea of
:> not having to remember to re-charge or having to throw away batteries,
:> but that's a lot of dough for a lighting system.

:Well, contrary to what the Minister of Lighting Misinformation may
:claim, hub generators are not the only generator game in town. I've
:got either bottle generators or roller (bottom bracket) generators on
:five bikes (i.e. my wife's and mine). They work fine for us, and for
:many other people.

:Now your winter riding sounds much more extreme than most people's,
:and that's where a hub unit would be better. But to get a taste of
:things, you could mount a more conventional generator during the
:summer and see how you like it. It would have a little less
:efficiency and (depending on model) might occasionally slip in the
:rain, but it would be a decent introduction to the technology.

I've tried to use a bottom bracket mounted bottle, and it just sucked.
it slipped in any rain, it made an awful racket when it was engaged.

A cheap hub is better, less noise, less wire mess, less drag, no slip.
Works in rain, snow or volcanic erruption.

I'd see if you can find someone to borrow a bike (or a wheel and
light) from, and ride it.

:She immediately got a wistful look on her face and said "Ohio! Oh, my

:brother is going to college in Ohio and he says it's just _beautiful_,
:all lush and green! I've wanted to go to Ohio ever since!" All I
:could say was "Yep, I love it. It's great for bicycling."

good drugs, good drugs.

--
sig 1

[Jay Beattie]

BTW, I don't consider my winter riding that extreme: lots of rain,
some ice, minor snow -- nothing like the Midwest or East Coast. I
might switch to studs if there is snow for more than a day or two or
ice, but I could just drive and then ride rollers for a few days. The
tough guys and gals are riding for months in snow and sub-zero
temperatures.

-- Jay Beattie.

[Dan O]

On Dec 31, 12:15 pm, Frank Krygowski <frkry...@gmail.com> wrote:
> On Dec 31, 12:41 pm, Dan O <danover...@gmail.com> wrote:
>
>
>
> > A little tiny dedicated worklight is apt to go dead right when you
> > need it most (a bike headlight will be maintained charged), the coin
> > cell LED lights I've ever seen all require to hold the switch down to
> > activate, and I've never used one beyond trying it to see if it works
> > and then I don't know where any of them went after that [I have no use
> > for them]. Heck, my Kryptonite U-lock key has a little flashlight
> > built in).
>
> I bought my first one of these in about 2001, from an outdoor store as
> I was on day one of a week-long bike tour to visit my daughter at her
> college. They had one model that was on only when you squeezed it,
> another with a stay-on switch. I paid an extra $1 for the latter.
>

That's the way to go. The only ones I've ever seen required to hold
down the switch. I've been given many; never carried or used one.

> I used it for reading in the tent at night, finding my campsite after
> trips to campground showers & rest rooms, etc. The battery lasted not
> only through that trip, but probably a year beyond, although most of
> that time it just sat in my pocket.
>
> As with a mini-Leatherman, I find it worth carrying all the time.
> I've recently used it to read notes on a breaker box, look at a map at
> night, etc.
>

I totally get it. (I have a complete collection of Hardy Boys mystery
stories :-)

> The only problem has been occasionally forgetting to take one out of
> my pocket before the pants get laundered. Sometimes they survive,
> sometimes they don't.
>

The survivors are apparently better made than my $60 PB headlight.

[SMS]

On 12/31/2012 4:19 PM, Joe Riel wrote:

> Possibly he meant a necessity from a marketing point of view, that is,
> if the manufacturer doesn't offer it, the sell will be lost. I've seen
> the occasional rider with a strobe on the front; under some conditions
> it increases the visibility but I'm not convinced dramatically. Hardly
> a necessity from this cyclist's point of view.

Quite rare around here to see a cyclist with lights where the front
light is not a strobe. That doesn't mean that there still aren't a lot
of night cyclists with no lights at all.

The increase in the cyclists daytime visibility is incredible. It's
especially effective at preventing vehicles from turning left in front
of either an oncoming cyclists and preventing vehicles from failing to
yield to cyclists where the cyclist has no stop sign but the vehicle does.

It's not a marketing thing at all, strobes work.

[Andre Jute]

On Tuesday, January 1, 2013 12:04:04 AM UTC, SMS wrote:
>
> What I'd like to see is a good rechargeable headlight that charges from
>
> a hub dynamo on a continuous basis, even in the day time, so external
>
> recharging is rarely needed. Shouldn't be too hard to do, but I think
>
> there's just no market for an even more expensive system.

I posted an outline design for doing exactly this to the Thorn Forum. As you will see if you visit, an outline design was all that was necessary because prebuilt modules to perform the necessary functions are available under ten bucks total from China. Several parties ordered modules identified by me and we'll see when they arrive and are constructed how well my design for a homebrew kit stacks up against the Tout Terrain and BUMMs E-Werk and the Basta Nano lamp with built-in charger when many of the tourers on that board already have. The idea is that the tourers will be able to recharge all their electronic devices (excluding an iPad, as that may require current which just isn't available, and control circuits I don't fancy amateurs soldering and then blaming me for when they inevitably eat an expensive iPad). http://www.thorncycles.co.uk/forums/index.php?topic=5271.0

Andre Jute

[James]

My Sanyo Dynapower roller dynamo, is meant to be mounted near the bottom
bracket, but that makes it hard to turn on/off, and it gets coated with
crud, and the mount damages the paint - or isn't suitable on a CF frame
at all. I solved all the issues by mounting it in front of the rear
brake. Your frame might be too tight to accommodate like this though...

http://www.flickr.com/photos/55102679@N05/5878886758/

You might pick one up on ebay?

A light is surely not that expensive. $600 and a lot of bother is an
overstatement.

--
JS.

[James]

<crickets/>

--
JS

[James]

I haven't noticed any slippage in wet weather with my Sanyo roller
dynamo, and it doesn't have a rubber coated roller.

I think the LED lights of mine don't offer as much drag perhaps.

--
JS.

[Andre Jute]

On Tuesday, January 1, 2013 3:52:21 AM UTC, SMS wrote:

> It's not a marketing thing at all, strobes work.

Scharfie gets something half-right occasionally. Strobes work; there are many psychological studies telling us they attract attention. Even Franki Shavelegs can't deny something so obvious.

I used blinkies front and rear in daylight and at night until I noticed that my BUMM Cyo/Fly front and Toplight Line Plus rear lamps are brighter than the blinkies I used (SUN/Cateye TL-LD1100). Since those lamps are LEDs with 50K hours MBTF ratings, it really doesn't matter if I run them 24/7. A few experiments soon convinced me that the latest BUMM lights are visible in daylight, and that just sweeping them through a car causes the approaching driver to slow down, and if he doesn't, sweeping the front light through his eyes, even in daylight, convinces him to be sensible. Thus battery blinkies are no longer required, as currently available lamps serve the same purpose of making the cyclist visible.

It is ironic that I achieve this state of security with lamps that Scharfie, without ever trying or perhaps even seeing them, condemns out of hand as inadequate. Y'all know I'm no slacker in condemning inadequate components, and I remember that, when I described a previous generation of BUMM as the crap that it undoubtedly was, some of the dumber denizens of RBT (who're permanent fashion victims and BUMMbuddies) were silly enough to reproach me for telling Andreas so to his face when he tried to defend the indefensible.

Your modern Cyo has shortcomings, sure (it always had inadequate side throw, despite what was said here recently, and the current series has a wretched, wretched, wretched hotspot, pictured here: http://coolmainpress.com/BICYCLINGbuildingpedelec6.html ). But inadequate light output is not one of those shortcomings. A Cyo/Fly puts more usable light on the road than most American cars, and in Europe, where we use better headlamps on our cars, it has a greater usable output than a VW Beetle had within living memory.

Scharfie is therefore once again pontificating from the depths of his abysmal ignorance.

And, lest the local wannabe polemicists demand to know how I know all this, I have both the "racing" and commuting first series Cyo, and the current series Fly, and also the Toplight Line Plus, and their immediate best predecessors for comparison. In addition I have both Shimano and SON hub dynamos and a humongous battery to provide steady state current for doung test.

Now Scharfie will whine that the lamps don't come on at slow speed. That's not true either. What is true is that the previous generation of halogen lamps didn't light up properly until 12 or 15kph on the SON dynamo, and much lower speeds on the Shimano. (I condemned the SON here on RBT for precisely that reason.) But the Cyo/Fly range are LED lamps and they light up strongly at speeds so low balance becomes questionable. Anyway, they have capacitors which charge in a couple of paces which provide a minimum of four minutes of power even at standstill.

A dynamo light setup (SON or Shimano hub dynamo, BUMM CYO/Fly together with the Line Plus at the back, or the superior but more expensive Phillips Saferide together with the matching rear lamp) is today without any doubt the most superior legal and secure light setup you can fit. (By secure I mean that you can buy a more powerful lamp, but it is stupid to use it on public roads because it becomes a psychological magnet attracting motorists to you, like moths to a candle. See the photo of the Fly head-on on an unlit road in the URL referenced above...) These BUMM and Phillips lamps for the first time provide car-strength lights to cyclists, and SON and Shimano make them battery free, permanent, maintenance free.

Andre Jute

[somebody]

On Mon, 31 Dec 2012 19:52:21 -0800, SMS <scharf...@geemail.com>
wrote:

On the way home from work the sun is low in the sky and traffic is
picking up. I can see the strobe light reflected in distant signs; I
suspect a steady light will be just more background noise.

And don't forget the dayglo/reflective vest. No batteries needed,
ever.

[Jay Beattie]

A dyno light that kicks out 750 lumens is not cheap, and I've had the
Sanyo in the past -- like the way past, probably 1982 -- and it didn't
last long before breaking, but then again, maybe new production is
better. I couldn't use it in your configuration because I use full
fenders, so it would have to be mounted on the BB and suffer through
lots of water and occasional full immersion. There are cheaper hub/
light combinations, but I don't like putting cheap stuff on a bike
that gets lots of miles in bad conditions because then I just end up
buying two or three.

-- Jay Beattie.

[Jeff Liebermann]

On Mon, 31 Dec 2012 09:17:17 -0800, sms <scharf...@geemail.com>
wrote:

>The best option for a small size repair flashlight is one
>that's powered by a single CR123A battery, i.e.
><http://dx.com/p/romisen-cree-rc-n3-3-mode-led-flashlight-1xcr123a-2xaa-9070>.

CR123A lithium manganese dioxide batteries are not rechargeable.
That's fine if you leave the house with a new battery. However, after
using it a few times, the charge condition will be guesswork. I
received a nice SomethingFire flashlight that uses two CR123A
batteries for Hannukah. Not having much experience with these
batteries, I proceeded to use the flashlight normally and eventually
ran the batteries down. It was only about 5 minutes between when I
noticed a drop in output and when the batteries were dead. Not enough
warning.

Also, there seems to be large variations in CR123A battery capacity at
high currents among vendors:
<http://www.powerstream.com/cr123a-tests.htm>
That's mostly because the CR123A really wasn't designed for high
current applications, such as flashlights.

Doing a bit of research, I found that rechargeable 16340 Li-Ion cells
are available:
<http://dx.com/s/16340.html?category=400>
I have some on order, but haven't received them yet. (Make sure you
get the ones labeled "protected"). The self-discharge rate is almost
as good as lithium, so they should be suitable as a replacement for my
current backup bicycle light:
<http://802.11junk.com/jeffl/pics/bicycles/bicycle-flashlight.jpg>
Note that the 3.6V nominal Li-Ion voltage is 20% higher than 3.0V
nominal lithium manganese dioxide voltage. Hopefully, it won't
destroy the flashlight.


--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[Dan O]

On Jan 1, 12:16 am, James <james.e.stew...@gmail.com> wrote:

I don't think any lighting is an absolute necessity - even for
nighttime riding.

[Sir Ridesalot]

A lot of Stealth Bicyclists don't think ANY light is needed at night even though it's required by law to have one. Are these the same bicyclists who demand equality under the law? Black or dark colour bicycles with a rider in back or dark colour clothing at night especially a moonles night in an area of poor or no ambient light from streetlights is NOT a good choice. When I see one of these "idiots" zoom out in front of a moving motor vehicle or other bicyclist causing them to have to brake hard to avoid hitting the "idiot" I sometimes, nay oftentimes, wonder how the "idiot" ever survives. Besides being illegal riding without lights puts a lot of bicyclists into the cagers' "they shouldn't be allowed on the road" mindset.

Be safe, be seen.

Happy new year and cheers.

[davethedave]

On Tue, 01 Jan 2013 10:47:45 -0800, Sir Ridesalot wrote:

>> I don't think any lighting is an absolute necessity - even for
>>
>> nighttime riding.
>
> A lot of Stealth Bicyclists don't think ANY light is needed at night
> even though it's required by law to have one. Are these the same
> bicyclists who demand equality under the law? Black or dark colour
> bicycles with a rider in back or dark colour clothing at night
> especially a moonles night in an area of poor or no ambient light from
> streetlights is NOT a good choice. When I see one of these "idiots" zoom
> out in front of a moving motor vehicle or other bicyclist causing them
> to have to brake hard to avoid hitting the "idiot" I sometimes, nay
> oftentimes, wonder how the "idiot" ever survives. Besides being illegal
> riding without lights puts a lot of bicyclists into the cagers' "they
> shouldn't be allowed on the road" mindset.

In some respects I disagree. Even with light coloured clothing you can't
be seen.

Lights are definitely the way forwards.
--
davethedave

[Dan O]

On Jan 1, 10:47 am, Sir Ridesalot <i_am_cycle_pat...@yahoo.ca> wrote:
> On Tuesday, January 1, 2013 1:37:36 PM UTC-5, Dan O wrote:
> > On Jan 1, 12:16 am, James <james.e.stew...@gmail.com> wrote:
>
> > > On 01/01/13 10:59, Frank Krygowski wrote:
>
> > > > On Dec 31, 10:01 am, SMS <scharf.ste...@geemail.com> wrote:
>
> > > >> 3. A front strobe is an absolute necessity. Almost no one will buy a
>
> > > >> front light without a daytime strobe. It's the equivalent of DRLs for cars.
>
> > > > How many readers think a front strobe is an absolute necessity for
>
> > > > daylight riding? Anyone besides SMS?
>
> > > <crickets/>
>
> > I don't think any lighting is an absolute necessity - even for
>
> > nighttime riding.
>
> A lot of Stealth Bicyclists don't think ANY light is needed at night even though it's required by law to have one. Are these the same bicyclists who demand equality under the law? Black or dark colour bicycles with a rider in back or dark colour clothing at night especially a moonles night in an area of poor or no ambient light from streetlights is NOT a good choice.
>

I said, "absolute necessity". I *do* appreciate the benefits of
supplemental lighting, and the safety and courtesy of conspicuous
visibility.

> When I see one of these "idiots" zoom out in front of a moving motor vehicle or other bicyclist causing them to have to brake hard to avoid hitting the "idiot" I sometimes, nay oftentimes, wonder how the "idiot" ever survives. Besides being illegal riding without lights puts a lot of bicyclists into the cagers' "they shouldn't be allowed on the road" mindset.
>
> Be safe, be seen.
>
> Happy new year and cheers.

And to you, with sincere best regards.

[James]

On 01/01/13 05:33, Phil W Lee wrote:
> sms<scharf...@geemail.com> considered Mon, 31 Dec 2012 09:17:17

> -0800 the perfect time to write:

>> With LED lamps things have improved somewhat since as long as the
>> LED lamp has sufficient thermal dissipation you can run it at higher
>> voltages without incident.
>

> It's even better than that, actually - both LEDs and dynamos are
> constant current devices, so they match each other perfectly, once you
> rectify the AC dynamo output to a DC LED input.
>

Better still, with multiple LEDs (2, 4, or 6 depending on their
electrical ratings), it is entirely feasible to rectify the AC *using*
the LEDs themselves, thereby eliminating any losses attributed to
rectifiers - which can be substantial unless a hybrid MOSFET rectifier
is used.

My headlight uses 4 CREE LEDs. Each has a forward voltage drop of about
3.? volts, and can withstand 5 volts in reverse. It has been in
operation now for over a year now with zero defects, several
compliments, and was mistaken by a policeman as an approaching motorbike!

--
JS.

[James]

Yeah, we used to just cut a slot in the fender and pop rivet a plastic
cover over the dynamo - similar to the PVC cover in the picture. Job done.

I haven't bought a commercial light, but the one Lou mentioned is less
than $200 - which is expensive just for a light, but likely a very good
light, and requires no batteries - ever - just breakfast and coffee ;-)

http://www.peterwhitecycles.com/supernova.asp

I like the beam pattern shots on this page (scroll down to see the
supernova) http://www.peterwhitecycles.com/headlights.asp

I'd like a fair bit more side spill for riding in the urban jungle, but
otherwise, what's to complain about?

--
JS.

[Jeff Liebermann]

On Mon, 31 Dec 2012 20:35:07 -0800 (PST), Andre Jute
<fiul...@yahoo.com> wrote:

>I posted an outline design for doing exactly this to the Thorn Forum. As you will see if you visit, an outline design was all that was necessary because prebuilt modules to perform the necessary functions are available under ten bucks total from China. Several parties ordered modules identified by me and we'll see when they arrive and are constructed how well my design for a homebrew kit stacks up against the Tout Terrain and BUMMs E-Werk and the Basta Nano lamp with built-in charger when many of the tourers on that board already have. The idea is that the tourers will be able to recharge all their electronic devices (excluding an iPad, as that may require current which just isn't available, and control circuits I don't fancy amateurs soldering and then blaming me for when they inevitably eat an expensive iPad). http://www.thorncycles.co.uk/forums/index.php?topic=5271.0
>
>Andre Jute

The problem with that scheme is that is uses a linear voltage
regulator. That's fine for very light loads, but is seriously
inefficient for anything that draws power. The size of the heatsink
would give a clue as to where the power is going. It's also not an
LDO (low dropout) regulator, which means that it stops regulating when
the input voltage drops below perhaps 2V above the output voltage
setting. The voltage drop through the input diode bridge certainly
doesn't help.

What you need is a switching regulator. Assuming an input of 6VAC at
0.5A (3 watts) and an output of 5V at 0.5A max, something like this
should work:
<http://www.ebay.com/itm/251169704387>
(Notice... no heat sink). Add a Shottky diode bridge and filter cap
on the input and you're done. With a usable input range of 1 to 5V,
it should also work at low speeds.

Disclaimer: I haven't tried it.

[Jay Beattie]

I don't know what's to complain about. I wish I could borrow a high
quality dyno set-up to see if it meets my needs. As I've grown older
and the weather gets worse -- and in an urban setting -- I've
developed an escalating dependence on lumens.

-- Jay Beattie.

[James]

How low can you get a Shottky diode forward voltage drop, with sensible
forward current and reverse voltage specs for the job?

Wouldn't it be better still to use a MOSFET bridge? MOSFET on
resistance these days can be pretty low, and a quad opamp IC to drive
them shouldn't be to difficult to arrange for even better performance,
at the cost of a few extra components that is.

--
JS.

[Frank Krygowski]

On Jan 1, 11:26 am, Jay Beattie <jbeat...@lindsayhart.com> wrote:
>
> A dyno light that kicks out 750 lumens is not cheap...

One of my oft-stated points here is that optics matter at least as
much as lumens. Too many people seem to think the optimum bike light
has lots and lots of lumens, and that it doesn't matter if they're all
concentrated into a round beam. But with decent road optics, you're
not wasting half of the lumens into the sky, and burning out your
retinas with the rest; you're putting them where they're needed.

Find someone with a good B&M headlight and take a ride together. I
think you'll see.

> and I've had the
> Sanyo in the past -- like the way past, probably 1982 -- and it didn't
> last long before breaking, but then again, maybe new production is
> better.

I think I bought mine in about 1978 or so. I just reinstalled it on
my wife's bike. Now maybe you got a bad one, or maybe they don't hold
up well to PDX-style immersion. I'm sure you do more rain riding than
I do.

> I couldn't use it in your configuration because I use full
> fenders, so it would have to be mounted on the BB and suffer through
> lots of water and occasional full immersion.

James's installation is pretty unique, and clever. I've seen photos
showing similar installations on front racks.

FWIW, that one is not my favorite generator. My main gripe was that
it has fewer poles per revolution (4 vs. the common 8) plus a larger
diameter than sidewall generators, and so low speed power output was
not enough for me. (I'm talking about things like riding paths
through a dark campground at near-walking speed).

But a sidewall generator can work well with fenders. I've seen
installations where the fender is bulged out where the generator
roller contacts the tire sidewall.

Better yet, one friend had a Cannondale with an AXA sidewall generator
that ran a rubber roller on the braking surface of the rim. He really
liked it. I duplicated that by cutting a groove in the roller of a
bog standard Union generator, and fitting a thick o-ring into the
groove. The o-ring running on the rim seems very smooth and low
drag. (Much of the drag of a tire driven generator occurs where the
tire contacts the roller.)

Again, you may want to do a bit of research to make sure any generator
you try has decent efficiency. However, that Union is nothing
special, and it's served well for many years, with no objectionable
friction. Unfortunately, it's time for a replacement; its top bearing
seems to be going, giving me rattly sounds. Time to pull another one
out of my "old generators" drawer.

- Frank Krygowski

[Frank Krygowski]

On Jan 1, 5:36 pm, Jeff Liebermann <je...@cruzio.com> wrote:
>
>
> What you need is a switching regulator.  Assuming an input of 6VAC at
> 0.5A (3 watts) and an output of 5V at 0.5A max, something like this
> should work:
> <http://www.ebay.com/itm/251169704387>
> (Notice... no heat sink).  Add a Shottky diode bridge and filter cap
> on the input and you're done.  With a usable input range of 1 to 5V,
> it should also work at low speeds.
>
> Disclaimer:  I haven't tried it.

I assume you're talking about a regulator based on pulse width
modulation, and I've wondered about whether such a thing can be used
with bike dynamos. I'm an ME, not an EE, but is it really feasible to
rapidly switch a power source with as much inductance as a dynamo?

- Frank Krygowski

[Jeff Liebermann]

On Wed, 02 Jan 2013 11:04:15 +1100, James <james.e...@gmail.com>
wrote:

>How low can you get a Schottky diode forward voltage drop, with sensible

>forward current and reverse voltage specs for the job?

0.15V to about 0.40V depending on forward current. My guess(tm) is
that this thing will be running at about 0.5A, which is the nominal
rating on dynamo.
<http://www.digikey.com/product-detail/en/CDBA340L-G/641-1258-1-ND/1963390?cur=USD>
The data sheet shows 0.25V at 0.5A. Two diodes in series for the
bridge would make it 0.5V drop total.

Also, note that there are other switchers for sale on eBay. I did
some more looking and found these that would probably be as good or
better.
<http://www.ebay.com/itm/261097668334>
<http://www.ebay.com/itm/180947008880>
Without a real data sheet, I can't tell what these things are doing. I
guess one has to buy an assortment and Learn By Destroying(tm).

>Wouldn't it be better still to use a MOSFET bridge? MOSFET on
>resistance these days can be pretty low, and a quad opamp IC to drive
>them shouldn't be to difficult to arrange for even better performance,
>at the cost of a few extra components that is.

Well, yes. A synchronous rectifier would be more efficient. See
circuit #12 at:
<http://pilom.com/BicycleElectronics/DynamoCircuits.htm>
However, we're talking the difference between 0.25V per device for
Schottky versus maybe 0.05V per device for an IR HexFET:
V = 0.5A * Rds = 0.5A * 0.1 ohms = 0.05V
At 0.5A, that's a power loss of:
W = 0.25V * 0.5A = 125 milliwatts
out of a delivered 3000 milliwatts from the dynamo. I think this can
be safely ignored in the name of simplicity.

Personally, I think the whole dynamo power LED light is done wrong and
reeks of ultra conservative design. The dynamos were originally
designed to power incandescent 6V lamps, which they do reasonably
well. The voltage and power output nicely match several 6V 0.2A bulbs
in parallel. However, nobody but kids and department store bicycle
shoppers buy incandescent bicycle lamps these daze. Time to
re-examine the assumptions.

The requirements for running a 2 watt LED are quite different. It
needs brightness regulation, dimming, and flashing. The circuitry
needed to do all this is inherently lossy when running a low voltages.
The solution is to build a dynamo that produces more voltage and less
current at the same power level. For the 3 watts, instead of 6V at
0.5A, it should produce 24V at 0.125A. This would go to a DC to DC
inverter to run the LED. While the forward voltage drop of the bridge
rectifier and saturation voltages of the switching components
contribute substantial losses in a low voltage system, they are far
less significant in a higher voltage system. If you want efficiency,
you need higher voltages. (As an added bonus, the copper losses in
the wiring will be less with higher voltages).

I have some other criticisms of bicycle generator technology, but that
can wait for another rant.


Dynamo-Powered LED Light Circuits for Bicycles
<http://pilom.com/BicycleElectronics/DynamoCircuits.htm>

Dynamo light testing:
<http://www.myra-simon.com/bike/dynotest.html>

Bicycle electric FAQ:
<http://www.burrow.ca/cyclist/bikecurrent-FAQ.html>

Worlds brightest bicycle light:
<http://tesladownunder.com/WorldsBrightestBike.htm>

Regulator for a Hub Dynamo:
<http://www.nscl.msu.edu/~daniel/sreg.htm>

Bicycle regulator:
<http://www.nscl.msu.edu/~daniel/regulator.html>
(This one charges the battery when the generator is idle).

[Andre Jute]

On Tuesday, January 1, 2013 10:36:38 PM UTC, Jeff Liebermann wrote:

> On Mon, 31 Dec 2012 20:35:07 -0800 (PST), Andre Jute wrote:
>
> >I posted an outline design for doing exactly this to the Thorn Forum. As you will see if you visit, an outline design was all that was necessary because prebuilt modules to perform the necessary functions are available under ten bucks total from China. Several parties ordered modules identified by me and we'll see when they arrive and are constructed how well my design for a homebrew kit stacks up against the Tout Terrain and BUMMs E-Werk and the Basta Nano lamp with built-in charger when many of the tourers on that board already have. The idea is that the tourers will be able to recharge all their electronic devices (excluding an iPad, as that may require current which just isn't available, and control circuits I don't fancy amateurs soldering and then blaming me for when they inevitably eat an expensive iPad). http://www.thorncycles.co.uk/forums/index.php?topic=5271.0
>
> >
>
> >Andre Jute
>
>
>
> The problem with that scheme is that is uses a linear voltage
>
> regulator. That's fine for very light loads, but is seriously
>
> inefficient for anything that draws power. The size of the heatsink
>
> would give a clue as to where the power is going. It's also not an
>
> LDO (low dropout) regulator, which means that it stops regulating when
>
> the input voltage drops below perhaps 2V above the output voltage
>
> setting. The voltage drop through the input diode bridge certainly
>
> doesn't help.
>
>
>
> What you need is a switching regulator. Assuming an input of 6VAC at
>
> 0.5A (3 watts) and an output of 5V at 0.5A max, something like this
>
> should work:
>
> <http://www.ebay.com/itm/251169704387>
>
> (Notice... no heat sink). Add a Shottky diode bridge and filter cap
>
> on the input and you're done. With a usable input range of 1 to 5V,
>
> it should also work at low speeds.
>
> Disclaimer: I haven't tried it.

Thanks, Jeff. That's where I was heading next. If you'd read all of the thread I referred you to, you'd discover that the outline design is not an engineering exercise but a teaching tool for people who know nothing, zilch, nada about electronics. You don't jump right in with switching designs, you first take them by the hand and put something linear they can understand in their hand. Then you can move on to switching designs.

Thanks for finding the right board for me!

Andre Jute

[Jeff Liebermann]

On Tue, 1 Jan 2013 17:22:51 -0800 (PST), Frank Krygowski
<frkr...@gmail.com> wrote:

>On Jan 1, 5:36�pm, Jeff Liebermann <je...@cruzio.com> wrote:
>>
>>
>> What you need is a switching regulator. �Assuming an input of 6VAC at
>> 0.5A (3 watts) and an output of 5V at 0.5A max, something like this
>> should work:
>> <http://www.ebay.com/itm/251169704387>
>> (Notice... no heat sink). �Add a Shottky diode bridge and filter cap
>> on the input and you're done. �With a usable input range of 1 to 5V,
>> it should also work at low speeds.
>>
>> Disclaimer: �I haven't tried it.

>I assume you're talking about a regulator based on pulse width
>modulation,

Correct.

>and I've wondered about whether such a thing can be used
>with bike dynamos. I'm an ME, not an EE, but is it really feasible to
>rapidly switch a power source with as much inductance as a dynamo?
>
>- Frank Krygowski

Yes, it can. Once the AC produced by the dynamo is converted to DC by
the bridge and the BFC (big fat capacitor), such things are easy. I
would not run unfiltered pulsed DC (i.e. half wave rectified) into the
DC to DC converter as that would surely cause problems.

The inductance of the power source is not a consideration. Only the
inductance or capacitance of the load is important. At the
frequencies typically used for controlling the brightness of an LED
(about 1KHz) the capacitance of the LED is not significant. There's
no inductance in the LED. At worst, the change in load resistance
during the on/off cycles might produce some ripple current in the BFC
after the diode bridge, which might cause some self heating. I doubt
if it will be significant, but the solution is to use either low-ESR
caps, or just a bigger capacitor.

[Jeff Liebermann]

On Tue, 1 Jan 2013 17:40:53 -0800 (PST), Andre Jute
<fiul...@yahoo.com> wrote:

>On Tuesday, January 1, 2013 10:36:38 PM UTC, Jeff Liebermann wrote:

>> <http://www.ebay.com/itm/251169704387>

>Thanks, Jeff. That's where I was heading next. If you'd read all of the thread I referred you to, you'd discover that the outline design is not an engineering exercise but a teaching tool for people who know nothing, zilch, nada about electronics. You don't jump right in with switching designs, you first take them by the hand and put something linear they can understand in their hand. Then you can move on to switching designs.
>
>Thanks for finding the right board for me!

I'm having 2nd thoughts about the first board I found. The problem is
the acceptable range of input voltages. According to my crude
testing, I can sometimes expect 10VAC from the dynamo at suicidal
speeds. That's higher than the range of acceptable input voltages.

There are three basic types of such DC to DC converters. Boost, Buck,
and Both. Boost requires that the output voltage is greater than the
input voltage. More simply, it can't output less than the voltage
input. Buck is the opposite, where the input voltage needs to be
greater than the output voltage. Both, can output both higher and
lower than the input, but is generally more complexicated.

I found these, which seem better.
<http://www.ebay.com/itm/261097668334>
<http://www.ebay.com/itm/400375205633>
2.5VDC to 6.0VDC input and 4VDC to 12VDC output. I'm not thrilled
with having 12VDC appear on a USB connector output. Careful with this
one.

<http://www.ebay.com/itm/180947008880>
4.75VDC to 35VDC input, which covers most of the range. Output is
1.25VDC to 26VDC, which should handle most anything.

<http://www.ebay.com/itm/390518044035>
3 to 5VDC input. 5V output. This has the same problem as the first
one, where it's a boost regulator, where the input voltage cannot be
higher than the 5V output voltage.

I'm sure there are more, but these are what I could find between
irritating phone calls from relatives and customers.

[Jeff Liebermann]

On Tue, 01 Jan 2013 18:19:54 -0800, Jeff Liebermann <je...@cruzio.com>
wrote:

One more:
<http://www.ebay.com/itm/310506835676>
3.5VDC to 30VDC input.
4-30VDC output at 2.5A max.
From the photos, it appears to be running at 80% efficiency.

So far, this one has the best chance because it can handle input
overvoltage. However, I can't tell what will happen if the output
voltage is set below the input voltage without actually trying it. The
auction title says "step up" (boost), which might be a problem.

[James]

I was thinking more like
<http://www.extremecircuits.net/2010/05/power-mosfet-bridge-rectifier.html>

The FETs used there have an Rds on of about 0.02 ohm.

> However, we're talking the difference between 0.25V per device for
> Schottky versus maybe 0.05V per device for an IR HexFET:
> V = 0.5A * Rds = 0.5A * 0.1 ohms = 0.05V
> At 0.5A, that's a power loss of:
> W = 0.25V * 0.5A = 125 milliwatts

And 25 milliwatts per FET (using your suggestion of 0.1 ohm on
resistance), plus a bit for the control circuit.

Let's not forget there are 2 devices on most of the time, so it's 250 mW
vs 50 mW.

> out of a delivered 3000 milliwatts from the dynamo. I think this can
> be safely ignored in the name of simplicity.

8.3% vs 1.7%? I know what I'd rather.

If the circuit was well designed and potted, I think it would be quite
reliable and simple enough not to cause issues. Power dissipation would
be so low that heat sinks would be unnecessary I think.

Obviously 4 Schottky diodes will be simpler and cheaper.

> Personally, I think the whole dynamo power LED light is done wrong and
> reeks of ultra conservative design. The dynamos were originally
> designed to power incandescent 6V lamps, which they do reasonably
> well. The voltage and power output nicely match several 6V 0.2A bulbs
> in parallel. However, nobody but kids and department store bicycle
> shoppers buy incandescent bicycle lamps these daze. Time to
> re-examine the assumptions.

Some dynamos with appropriate globes obviously used to work ok most of
the time. My dynamo doesn't have very good regulation, and used to blow
globes at the most inopportune times, i.e. going fast down hill.

I find the dynamo output and LED driving requirements to be a match made
in heaven. They love each other and have no need for external bits to
make them work well together - and much better than incandescents!

> The requirements for running a 2 watt LED are quite different. It
> needs brightness regulation, dimming, and flashing. The circuitry
> needed to do all this is inherently lossy when running a low voltages.
> The solution is to build a dynamo that produces more voltage and less
> current at the same power level. For the 3 watts, instead of 6V at
> 0.5A, it should produce 24V at 0.125A. This would go to a DC to DC
> inverter to run the LED. While the forward voltage drop of the bridge
> rectifier and saturation voltages of the switching components
> contribute substantial losses in a low voltage system, they are far
> less significant in a higher voltage system. If you want efficiency,
> you need higher voltages. (As an added bonus, the copper losses in
> the wiring will be less with higher voltages).

Flashing and dimming? C'mon. Talk about trying to keep it simple! ;-)

Oh, and I thought we wanted to rectify the dynamo output to charge some
battery?

But anyway, try running a dynamo with less load and you will find the
output voltage is higher. Mine with a constant 14.2 ohm load produces
6.8 V/0.47 A @ 20 km/h. At 30 km/h, it's producing 8.2 V / 0.58 A, and
at 50 km/h, 9.3 V / 0.65 A. (Do some power calcs and see there is far
more than 3 W coming from my 3 W dynamo ;-)

My LED lights are starting to work (producing reasonably bright light)
at just above walking pace (5-6 km/h), with only about 3 V / 0.22 A from
the dynamo.

You want higher voltages? Run at reduced load, or add a transformer!
(I know, the weight weenies will hang me for that one ;-)

But, I think low voltage, low loss designs are not that difficult these
days.

> I have some other criticisms of bicycle generator technology, but that
> can wait for another rant.
>
>
> Dynamo-Powered LED Light Circuits for Bicycles
> <http://pilom.com/BicycleElectronics/DynamoCircuits.htm>

Read it already.

> Dynamo light testing:
> <http://www.myra-simon.com/bike/dynotest.html>

Been there. Done my own testing ;-)

--
JS.

[James]

On 02/01/13 13:19, Jeff Liebermann wrote:
> On Tue, 1 Jan 2013 17:40:53 -0800 (PST), Andre Jute
> <fiul...@yahoo.com> wrote:
>
>> On Tuesday, January 1, 2013 10:36:38 PM UTC, Jeff Liebermann wrote:
>>> <http://www.ebay.com/itm/251169704387>
>
>> Thanks, Jeff. That's where I was heading next. If you'd read all of the thread I referred you to, you'd discover that the outline design is not an engineering exercise but a teaching tool for people who know nothing, zilch, nada about electronics. You don't jump right in with switching designs, you first take them by the hand and put something linear they can understand in their hand. Then you can move on to switching designs.
>>
>> Thanks for finding the right board for me!
>
> I'm having 2nd thoughts about the first board I found. The problem is
> the acceptable range of input voltages. According to my crude
> testing, I can sometimes expect 10VAC from the dynamo at suicidal
> speeds. That's higher than the range of acceptable input voltages.
>

I was going to say as much.

A buck regulator would be a better choice in my opinion. Forget the
boost, unless you ride at snails pace ( < 15 km/h ?) all the time.

--
JS.

[James]

I think you may find some USB devices do not charge from a simple 5 volt
supply. The reason being that they do not switch on their charging
circuit unless they can communicate with the USB host device (normally a
PC) and get approval to sink 0.5A.

Incidentally, some plug packs designed for charging USB devices (such as
iPads) have a small microprocessor inside that handles this
communication so that pedantic USB devices will start to charge.

--
JS

[Andre Jute]

Replying to all your posts, Jeff, this is a superb amount of information, some of which I will lift whole for explanations to my guys.

In fact, I already have an LM2596HVS buck module on my desk, originally intended to power 6V BUMM Cyo and D-Toplight from the battery on my pedelec. But BUMM came out with an E-Fly with electronics up to the peak 42V of my nominally 36V battery built in, so I just bought that instead because I was in a hurry and the heatsink to transfer the heat to the bicycle's steel frame still needed quite a bit of patient filing...

Thanks man, you're a lifesaver.

Andre Jute

[James]

On 02/01/13 12:40, Andre Jute wrote:

BTW, have you seen this?

http://www.bicycles.net.au/2012/09/lightcharge-hub-dynamo-powered-bicycle-usb-charger/

--
JS

[Frank Krygowski]

On Jan 1, 8:52 pm, Jeff Liebermann <je...@cruzio.com> wrote:
>
> >> Disclaimer: I haven't tried it.
> >I assume you're talking about a regulator based on pulse width
> >modulation,

> >and I've wondered about whether such a thing can be used
> >with bike dynamos. I'm an ME, not an EE, but is it really feasible to
> >rapidly switch a power source with as much inductance as a dynamo?
>
> >- Frank Krygowski
>
> Yes, it can.  Once the AC produced by the dynamo is converted to DC by
> the bridge and the BFC (big fat capacitor), such things are easy.  I
> would not run unfiltered pulsed DC (i.e. half wave rectified) into the
> DC to DC converter as that would surely cause problems.

OK. I didn't realize you had a capacitor in there. I was imagining
switching the input directly.

> The inductance of the power source is not a consideration.  Only the
> inductance or capacitance of the load is important.

Well, in general I'm not sure that's true. I'm thinking of a magneto
or points+coil system with the load being the simple resistance of the
spark plug. Suddenly shutting off the coil dumps a lot of energy into
the resistive load. I'd think that switching a dynamo directly
(without the rectifier and capacitor) would blow out the PWM unit.
The rectifier and capacitor make it different, though.

Again, I'm an ME not an EE, so I'll accept some education on this.

- Frank Krygowski

[Jeff Liebermann]

On Wed, 02 Jan 2013 14:21:33 +1100, James <james.e...@gmail.com>
wrote:

>I was thinking more like
><http://www.extremecircuits.net/2010/05/power-mosfet-bridge-rectifier.html>
>The FETs used there have an Rds on of about 0.02 ohm.

Retch. 1% resistors? There's a reason the values are so critical. If
the driver phase angles aren't exactly 180 degrees, there's a really
good chance that the pull up and pull down MOSFET's are going to
conduct simultaneously. Shorting the power source for a few degrees
twice every cycle would not be a good thing. Even if the driver op
amps were exactly 180 degrees out of phase, any noise around the zero
crossing from the generator will produce the same result. It needs a
dead band around zero volts (which is a good idea anyway because
there's no output at zero volts), to prevent this from happening. I
also don't see any upper frequency limiting, no op amp compensation,
no oscillation prevention tricks on the MOSFET's, and slew rate
limiting. None of these are really necessary, but they do offer
benefits in real world applications, where the load doesn't quite look
totally resistive.

The original article came from Elektor Magazine:
<http://www.elektor.com/magazines/2006/july/power-mosfet-bridge-rectifier.58316.lynkx>
(subscription required to view)
Some not very nice comments on the design:
<http://www.elektor.com/forum/elektor-forums/general-topics/power-supplies/mosfet-bridge-rectifier-not-working!.612569.lynkx>

>> However, we're talking the difference between 0.25V per device for
>> Schottky versus maybe 0.05V per device for an IR HexFET:
>> V = 0.5A * Rds = 0.5A * 0.1 ohms = 0.05V
>> At 0.5A, that's a power loss of:
>> W = 0.25V * 0.5A = 125 milliwatts
>
>And 25 milliwatts per FET (using your suggestion of 0.1 ohm on
>resistance), plus a bit for the control circuit.
>
>Let's not forget there are 2 devices on most of the time, so it's 250 mW
>vs 50 mW.
>
>> out of a delivered 3000 milliwatts from the dynamo. I think this can
>> be safely ignored in the name of simplicity.
>
>8.3% vs 1.7%? I know what I'd rather.

Agreed. 8.3% out of 3 watts would be about 250 milliwatts of
excessive drag (or wasted energy). I think I can handle that.

>If the circuit was well designed and potted, I think it would be quite
>reliable and simple enough not to cause issues. Power dissipation would
>be so low that heat sinks would be unnecessary I think.

The switchers I excavated from eBay were running at about 80%
efficiency (even though they claimed higher). 20% of 3 watts is 600
milliwatts of heat. That seems a bit on the high side for potting in
something that's not thermally conductive. Allowing the chips to
radiate the heat and allowing some air flow might be useful. On the
other foot, I've potted stuff in allegedly thermally conductive epoxy
and gotten good results at 10 watts dissipation in still air.
<http://www.mgchemicals.com/products/protective-coatings/epoxy-potting-and-encapsulating-compounds/thermally-conductive-epoxy-832tc/>

>Obviously 4 Schottky diodes will be simpler and cheaper.

Also more reliable.

>Some dynamos with appropriate globes obviously used to work ok most of
>the time. My dynamo doesn't have very good regulation, and used to blow
>globes at the most inopportune times, i.e. going fast down hill.

What's a globe? A lamp? Yeah, I can see that happening. With an
incandescent lamp, the bulb life goes down 60% with a 5% increase in
applied voltage. It doesn't take much overvoltage to kill an
incandescent lamp. However, it's assumed that LED's have current
regulators, which prevents blowing the LED with too much voltage.

>I find the dynamo output and LED driving requirements to be a match made
>in heaven. They love each other and have no need for external bits to
>make them work well together - and much better than incandescents!

I don't. To get constant output from an LED, with varying input
voltages, you need all those "extra bits" to make it work. Those
"extra bits" tend to involve voltage drops, which make the 6VAC output
far from ideal.

>Flashing and dimming? C'mon. Talk about trying to keep it simple! ;-)

The logic is that once the "intelligence" is added to the design, such
software only features are essentially free. I'm thinking in terms of
a PIC controller. Add in a turn signal indicator. It's also free.
Hmmm... with 3 watts, I can almost keep my coffee warm.

>Oh, and I thought we wanted to rectify the dynamo output to charge some
>battery?

Yep. However, while attempting to achieve that goal, I took the
liberty of changing everything and redesigning the entire system. I
did stop at the generator, although I was tempted to continue by
redesigning the bicycle to make it easier to attach. I get carried
away sometimes.

>But anyway, try running a dynamo with less load and you will find the
>output voltage is higher. Mine with a constant 14.2 ohm load produces
>6.8 V/0.47 A @ 20 km/h. At 30 km/h, it's producing 8.2 V / 0.58 A, and
>at 50 km/h, 9.3 V / 0.65 A. (Do some power calcs and see there is far
>more than 3 W coming from my 3 W dynamo ;-)

Good to know.
<http://www.myra-simon.com/bike/dynotest.html>
From the electrical output curve, it looks like it levels off at 4
watts. I think the core saturation flattening out of the curve is
intentional, introduced by the designers to keep from turning your
head lamp into a photo flash bulb. Again, this is legacy rubbish
designed solely for incandescent bulbs. LED lights would require
current regulators and therefore can handle the over-voltage. Instead
of having the curve flatten out as in the above URL, it will simply
continue to increase in a straight line, giving far more power than
todays dynamo. If it puts out 50VAC, that's fine as long as the
regulator(s) can handle it.

>My LED lights are starting to work (producing reasonably bright light)
>at just above walking pace (5-6 km/h), with only about 3 V / 0.22 A from
>the dynamo.

They probably have an internal current regulator. Try a DC power
supply in place of the AC dynamo. Plot the input voltage and current
curves. I think you'll find that as the voltage goes up, the current
goes down.

>You want higher voltages? Run at reduced load, or add a transformer!
>(I know, the weight weenies will hang me for that one ;-)

Never mind the weight. It's the lousy efficiency of a transformer
that will cause problem. If it were running at one frequency,
preferably high enough that ferrites could be substituted for
laminated iron, I could probably squeeze 90% efficiency out of the
transformer. However, with the wildly varying frequency coming out of
the generator, I would be lucky if I could get 60% efficiency. No
thanks.

>But, I think low voltage, low loss designs are not that difficult these
>days.

I don't think it's that easy. I won't know until I try it. Things
are never as simple as they first appear.

[Frank Krygowski]

On Jan 1, 9:19 pm, Jeff Liebermann <je...@cruzio.com> wrote:
> On Tue, 1 Jan 2013 17:40:53 -0800 (PST), Andre Jute
>

> <fiult...@yahoo.com> wrote:
> >On Tuesday, January 1, 2013 10:36:38 PM UTC, Jeff Liebermann wrote:
> >> <http://www.ebay.com/itm/251169704387>
> >Thanks, Jeff. That's where I was heading next. If you'd read all of the thread I referred you to, you'd discover that the outline design is not an engineering exercise but a teaching tool for people who know nothing, zilch, nada about electronics. You don't jump right in with switching designs, you first take them by the hand and put something linear they can understand in their hand. Then you can move on to switching designs.
>
> >Thanks for finding the right board for me!
>
> I'm having 2nd thoughts about the first board I found.  The problem is
> the acceptable range of input voltages.  According to my crude
> testing, I can sometimes expect 10VAC from the dynamo at suicidal
> speeds.  That's higher than the range of acceptable input voltages.

I think James has already covered this with some numbers, but just to
confirm: You can get a heck of a lot more than 10 volts out of a bike
generator, and it doesn't take suicidal speeds.

Bike generators should really not be rated "6V 3W". They should be
rated "0.5 Amp." They try to put out at least roughly that rated
current (some more precisely than others) no matter what the resistive
load. Give them an open circuit, and their output voltage can be
quite high. I've measured as much as 35 Volts.

If the input resistance of your device is low, the generator won't
produce much voltage. If it's high, the voltage can be very high.
It's just way different from batteries, which most of these devices
are designed for.

As James has said, you've already got roughly constant current from
the basic nature of the bike generator. (It comes from a balance
between Faraday's law - more output at higher speeds - and inductive
reactance - more reactance at higher frequencies.)

LEDs need constant current. There's not much need for a lot of
complexity.

- Frank Krygowski

- Frank Krygowski

[Frank Krygowski]

On Jan 1, 10:21 pm, James <james.e.stew...@gmail.com> wrote:

>
> Some dynamos with appropriate globes obviously used to work ok most of
> the time.  My dynamo doesn't have very good regulation, and used to blow
> globes at the most inopportune times, i.e. going fast down hill.

I have one of those and put it on an oscilloscope. While I don't
understand the details of different bike dynamo winding schemes, etc.,
I know that the Sanyo's output had a very different waveform than the
other ones I've tested. And IIRC its self-regulation was not nearly
as good as others.

> I find the dynamo output and LED driving requirements to be a match made
> in heaven.  They love each other and have no need for external bits to
> make them work well together - and much better than incandescents!

I strongly agree with this.

The only downsides to James's multi-LED self-rectification scheme is
the cost of the multiple high-quality LEDs (which is modest). I think
that if we could get proper lenses or reflectors to shape the beam to
the road, that's all we really need.

> But anyway, try running a dynamo with less load and you will find the
> output voltage is higher.  Mine with a constant 14.2 ohm load produces
> 6.8 V/0.47 A @ 20 km/h.  At 30 km/h, it's producing 8.2 V / 0.58 A, and
> at 50 km/h, 9.3 V / 0.65 A.  (Do some power calcs and see there is far
> more than 3 W coming from my 3 W dynamo ;-)

I think you misstated something there. Within reason, more resistive
load (not less) gives higher outputs, both higher voltage and higher
power. If you assume output of constant current (roughly 0.5 Amp),
Ohm's Law tells you what you need to know.

This is why, with halogen bulbs, it was possible to run two headlights
in series from many bike generators. At high enough speeds (about 14
mph with my Soubitez roller unit) voltage would roughly double,
current would stay the same, and both lamps in series would light
nicely.

Of course, input power would also go up, so resistance torque at the
tire-roller contact point would also go up. Not a problem with a hub
dynamo. Not much problem with the roller units I used. But it would
be a problem with the smaller diameter drive roller on most bottle
units.

The LED lights seem to effectively draw less voltage, so the drag of
the generator is less. It's not easy to measure drag, though, and I
haven't done it since the halogen light days.

- Frank Krygowski

[Jeff Liebermann]

On Tue, 1 Jan 2013 20:54:03 -0800 (PST), Frank Krygowski
<frkr...@gmail.com> wrote:

>OK. I didn't realize you had a capacitor in there. I was imagining
>switching the input directly.

There has to be a capacitor to smooth out the rectified AC into
something resembling DC. That's why the various eBay devices are
called "DC to DC converters".

>> The inductance of the power source is not a consideration.  Only the
>> inductance or capacitance of the load is important.
>
>Well, in general I'm not sure that's true. I'm thinking of a magneto
>or points+coil system with the load being the simple resistance of the
>spark plug. Suddenly shutting off the coil dumps a lot of energy into
>the resistive load. I'd think that switching a dynamo directly
>(without the rectifier and capacitor) would blow out the PWM unit.
>The rectifier and capacitor make it different, though.

Back EMF, which is what your talking about, is a function of how much
energy can be produced by the windings in an inductor when the field
collapses. As you indicate for the Kettering ignition system, you
first run current through the inductor winding, and then OPEN the
connection (points). This causes the magnetic field to collapse
across the inductor, coupled to the high voltage secondary, producing
a high voltage spark. (The capacitor resonates the ignition coil at
the approximate frequency of engine RPM, which reduces pitting of the
points due to arcing).

Trying to do the same with a bicycle permanent magnet generator is not
going to work. The only time there's current in the windings is when
the dynamo is running. You would need to disconnect the circuit
(bridge rectifiers and capacitor) at the peak of the cycle, in order
to get any kind of spark across the connection. Even so, the circuit
is disconnected, and will not see any high voltage from the back EMF.
Reconnecting the circuit does nothing because the magnetic field has
collapsed long before the connection is made.

However, there's a different mechanism that can cause problems called
inrush surge current. If you spin up the generator, without the
diodes and capacitor connected, and then apply the circuit connection,
the generator will deliver it's full power (about 5 watts max)
directly into the diodes as the capacitor charges up from zero.
Effectively, the capacitor is a dead short and the full current is
going through the diodes. The Schottky diodes I specified were good
for 3A which is marginal for such a current surge. The problem can be
solved with the inclusion of an NTC (negative temperature coefficient)
surge supressor:
<http://www.rti-corp.com/Electronics/surggard.htm>
but that creates losses that are probably not tolerable. So, bigger
diodes are the easy solution.

If I left something out, please ask.

>Again, I'm an ME not an EE, so I'll accept some education on this.

The basic rule is that anyone can design a circuit the functions.
That's the easy part. More expertise and experience is required to
design one that survives the user environment, passes the regulatory
compliance hurtles, can be built, and is reliable.

[Dan O]

On Jan 1, 10:10 pm, Phil W Lee <p...@lee-family.me.uk> wrote:
> James <james.e.stew...@gmail.com> considered Wed, 02 Jan 2013 14:21:33

> +1100 the perfect time to write:
>
>
>
> >On 02/01/13 12:25, Jeff Liebermann wrote:

> >> On Wed, 02 Jan 2013 11:04:15 +1100, James<james.e.stew...@gmail.com>

> >> wrote:
>
> >>> How low can you get a Schottky diode forward voltage drop, with sensible
> >>> forward current and reverse voltage specs for the job?
>
> >> 0.15V to about 0.40V depending on forward current. My guess(tm) is
> >> that this thing will be running at about 0.5A, which is the nominal
> >> rating on dynamo.

> >> <http://www.digikey.com/product-detail/en/CDBA340L-G/641-1258-1-ND/196...>

> >> The data sheet shows 0.25V at 0.5A. Two diodes in series for the
> >> bridge would make it 0.5V drop total.
>
> >> Also, note that there are other switchers for sale on eBay. I did
> >> some more looking and found these that would probably be as good or
> >> better.
> >> <http://www.ebay.com/itm/261097668334>
> >> <http://www.ebay.com/itm/180947008880>
> >> Without a real data sheet, I can't tell what these things are doing. I
> >> guess one has to buy an assortment and Learn By Destroying(tm).
>
> >>> Wouldn't it be better still to use a MOSFET bridge? MOSFET on
> >>> resistance these days can be pretty low, and a quad opamp IC to drive
> >>> them shouldn't be to difficult to arrange for even better performance,
> >>> at the cost of a few extra components that is.
>
> >> Well, yes. A synchronous rectifier would be more efficient. See
> >> circuit #12 at:
> >> <http://pilom.com/BicycleElectronics/DynamoCircuits.htm>
>
> >I was thinking more like

> ><http://www.extremecircuits.net/2010/05/power-mosfet-bridge-rectifier....>

> Or at least a supercap, to provide a standlight - far more important
> than a strobe or dimmer, in my opinion.
>

I agree that staying lit when you want it to is a fundamentally more
important function for a bike light than flashing mode. It's sort of
inherent in battery lights.

The flashing mode isn't particularly important to me, but if it's
there, and ambient light is such that the solid on headlight is not
needed to see by, and traffic circumstances are such that being
noticed may be a concern, and I can easily reach the switch on the
handlebar, well...

And then - with battery lights - there is the issue of runtime and is
a flashing light (to be seen) better than no light at all.

<snip>