Rohloff Speedhub Electronic Gear Shift
Andre Jute
SHIFTEZY PushButton Gear Shift
What do you reckon, can I drive the gubbins off a dynamo, like the
Cyber Nexus full-auto gearshift on my Trek?
Andre Jute
The rest is magic hidden in the hub.
For rare hub gear bikes, visit Jute on Bicycles at
http://www.audio-talk.co.uk/fiultra/BICYCLE%20%26%20CYCLING.html
James
> Rohloff Speedhub Electronic Gear Shift
> SHIFTEZY PushButton Gear Shift
>
>
> What do you reckon, can I drive the gubbins off a dynamo, like the
> Cyber Nexus full-auto gearshift on my Trek?
I reckon so, with a full wave bridge, filter caps and a linear reg or
switch mode supply. But then you've probably eaten the 160gms weight
saving and created a less reliable system than the cables you had.
I wonder how much their battery weighs? More than 160gms?
"ShiftEzy", is that like "Beetle Lax"? Does it make your Ringo?
Have fun with that.
JS.
Chalo
> Rohloff Speedhub Electronic Gear Shift
> SHIFTEZY PushButton Gear Shift
>
> http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=330458078660&fr...
>
> What do you reckon, can I drive the gubbins off a dynamo, like the
> Cyber Nexus full-auto gearshift on my Trek?
Any system that can develop the torque it takes to shift my Rohloff
hub would be a pretty substantial piece of equipment.
Chalo
m-gineering
You'd be surpised how much friction there is in the cables etc. To get
an idea put a 8mm wrench over the shifthexagon on the hub (easy with the
EX) and compare
--
/Marten
info(apestaartje)m-gineering(punt)nl
Chalo
>
> Chalo wrote:
> >
> > Any system that can develop the torque it takes to shift my Rohloff
> > hub would be a pretty substantial piece of equipment.
>
> an idea put a 8mm wrench over the shifthexagon on the hub (easy with the
> EX) and compare
I've redone my cables a few times, settling on full housing and a
liberal amount of free play as the best way to minimize cable drag.
My Speedhub is clearly harder to shift than my wife's, which I also
set up with full housing. This is the case whether I check at the hub
or at the shifter.
Chalo
m-gineering
as from #18200 the detent springs were modified. Is yours an early one?
--
/Marten
info(apestaartje)m-gineering(punt)nl
Andre Jute
> Rohloff Speedhub Electronic Gear Shift
> SHIFTEZY PushButton Gear Shift
>
>
> What do you reckon, can I drive the gubbins off a dynamo, like the
> Cyber Nexus full-auto gearshift on my Trek?
I wrote away asking for technical particulars and I've now heard from
Edwin Sochen of Edsan Automation Systems, makers of the SHIFTEZY
PushButton Rohloff Speedhub Gear Shift:
***
"It's quite a coincidence that you mention a dynamo. It so happens
that we are working on a dynamo regulator/inverter/charger for our
system which should be available within the next few weeks. We are
trialling our unit with a Schmitt SON delux but any dynamo with a 6v
AC output will do. As you probably know, there is a unit out of
Germany (e-Werk) but it is a bit expensive.
"The ShiftEzy system uses a 12v Lithium-Ion 1800mAh battery. With no
gear change, the system draws 16.5 mA. On a gear change about 708 mA
(0.2 sec).
"Strictly speaking, I suppose our system would work without the
battery but obviously you won't be able to change gears whilst at
standstill unless you have a huge capacitor in the system."
***
Now we're getting into the real world of Rohloff users!
By the way, it has just occurred to me that the big attraction of the
SHIFTEZY for many will be the ability to use drop handles with your
Rohloff gearbox... And for many of them the SHIFTEZY in the battery
version already on offer will be fine, because they are used to
charging commuting lights.
***
Getting back to using the SHIFTEZY with a hub dynamo rather than the
supplied wallwart charger.
I like the big capacitor better than a battery, simply because the cap
will be smaller if not necessarily lighter, and caps are always less
trouble than batteries.
Anyone who wants to use a hub dynamo with a SHIFTEZY and doesn't want
to wait until Edsan has their regulator/inverter/charger ready could
buy a SHIFTEZY now, buy BUMM's E-Werk, and be ready to go. The E-Werk
is likely to be more versatile than the dedicated but (promised to be)
cheaper versions for the SHIFTEZY.
Andre Jute
The rest is magic hidden in the hub.
For rare hub gear bikes, visit Jute on Bicycles at
http://www.audio-talk.co.uk/fiultra/BICYCLE%20%26%20CYCLING.html
PS I have no connection Edsan Automation Systems; I'm just a gearhead.
Andre Jute
According to Edwin Sochen of Edsan Automation Systems, maker of the
SHIFTEZY PushButton Rohloff Speedhub Gear Shift:
"The ShiftEzy system uses a 12v Lithium-Ion 1800mAh battery. With no
gear change, the system draws 16.5 mA. On a gear change about 708 mA
(0.2 sec)."
I agree with Marten, turning the gearbox with a spanner on the 8mm nut
on the EX box is subjectively easier than turning it with the rotary
grip, though mine are getting much closer now that the rotary change
has softened up (probably just worn in or progressively better
adjusted).
Andre Jute
"The brain of an engineer is a delicate instrument which must be
protected against the unevenness of the ground." -- Wifredo-Pelayo
Ricart Medina
"Musta been before the discovery of Big Apples." -- Andre Jute
(PeteCresswell)
>Any system that can develop the torque it takes to shift my Rohloff
>hub would be a pretty substantial piece of equipment.
Some hubs shift easier than others. Something about their using
a weaker spring after a certain date.
I've got an older hub that's *really* hard to shift and a newer
one where the shifting is almost effortless.
--
PeteCresswell
Chalo
>
> Chalo wrote:
> >
> > My Speedhub is clearly harder to shift than my wife's, which I also
> > set up with full housing. This is the case whether I check at the hub
> > or at the shifter.
>
Mine is serial number 5xxx, but my wife's is serial number 6xxx. They
differ in the effort it takes to shift, though.
Chalo
Andre Jute
May be worth getting the softer spring that Rohloff fits now.
My Rohloff, an EX box, has lost a great deal of the notchiness I
observed when new and is now as effortless as Pete describes his.
Maybe not Shimano Nexus smooth but good enough.
In fact my Rohloff is now smooth enough that I'm considering the Edsan
SHIFTEZY // hub dynamo combo not so much because I want easier
electronically assisted shifting but because I might be able to use
the SHIFTEZY/hub dynamo/inverter as a shortcut to a *full auto* box by
adding speed sensing electronics of my own. This might amaze you, but
for me the mechanics of mounting the stepper motors etc are far more
difficult to achieve than the electronics, which I can usually knock
up myself or, if SMT which are a bit small for me these days, get
soldered for asking by young friends for whom I design stuff. I
described a stepper motor model of electronically assisted Rohloff
shifting on RBT with Tom Ace and others a year or so ago.
Andre Jute
Visit Jute on Amps at
http://www.audio-talk.co.uk/fiultra/
"wonderfully well written and reasoned information for the tube audio
constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site containing vital gems of
wisdom"
Stuart Perry Hi-Fi News & Record Review
James
> Andre Jute <fiult...@yahoo.com> wrote:
>
> > Rohloff Speedhub Electronic Gear Shift
> > SHIFTEZY PushButton Gear Shift
>
> >http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=330458078660&fr...
>
> > What do you reckon, can I drive the gubbins off a dynamo, like the
> > Cyber Nexus full-auto gearshift on my Trek?
>
> I wrote away asking for technical particulars and I've now heard from
> Edwin Sochen of Edsan Automation Systems, makers of the SHIFTEZY
> PushButton Rohloff Speedhub Gear Shift:
>
> ***
>
> "The ShiftEzy system uses a 12v Lithium-Ion 1800mAh battery. With no
> gear change, the system draws 16.5 mA. On a gear change about 708 mA
> (0.2 sec).
What does it do with the 16.5mA?
0.708A x 0.2s = 0.1416 coulombs
For a capacitor, charge in coulombs q = CV
0.1416 / 12 = 0.0118 Farad, or 11.8mF. That wont do though, as the
capacitor voltage will be zero after dumping its charge.
Assuming the gear changer mechanism is simply a MOSFET switch and some
actuator coil, it can likely withstand a large input voltage range for
a short time. You could for instance, possibly, charge the cap to 18
V and have it discharge to 6V during the gear change, but that doesn't
allow for a bad change that takes 2-3 times longer than normal, or a
worn and sticky mechanism. The capacitor would need to be probably 10
times bigger.
A 120mF electrolytic is going to be pretty big. Think of a 1F cap you
can get for a car stereo is about as big as a coke can. It'll be of
similar proportions size. Here's a 100mF 25V cap
http://www.tedss.com/item.asp?id=2020005300
3" diameter x 3.7" long. Now the battery system might actually be
smaller, because you could keep a much smaller battery charged by the
dynamo for ever. It wouldn't need to be anywhere near as big as
theirs or the cap.
> "Strictly speaking, I suppose our system would work without the
> battery but obviously you won't be able to change gears whilst at
> standstill unless you have a huge capacitor in the system."
>
> ***
Ah ha.
> I like the big capacitor better than a battery, simply because the cap
> will be smaller if not necessarily lighter, and caps are always less
> trouble than batteries.
True, but you'll still need a rectifier and boost converter to get
enough charge into a cap.
JS.
(I hope this wasn't too long for Ed.)
Andre Jute
> On Aug 25, 6:58 pm, Andre Jute <fiult...@yahoo.com> wrote:
>
> > Andre Jute <fiult...@yahoo.com> wrote:
>
> > > Rohloff Speedhub Electronic Gear Shift
> > > SHIFTEZY PushButton Gear Shift
>
> > >http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=330458078660&fr...
>
> > > What do you reckon, can I drive the gubbins off a dynamo, like the
> > > Cyber Nexus full-auto gearshift on my Trek?
>
> > I wrote away asking for technical particulars and I've now heard from
> > Edwin Sochen of Edsan Automation Systems, makers of the SHIFTEZY
> > PushButton Rohloff Speedhub Gear Shift:
>
> > ***
>
> > "The ShiftEzy system uses a 12v Lithium-Ion 1800mAh battery. With no
> > gear change, the system draws 16.5 mA. On a gear change about 708 mA
> > (0.2 sec).
>
> What does it do with the 16.5mA?
>
> 0.708A x 0.2s = 0.1416 coulombs
>
> For a capacitor, charge in coulombs q = CV
>
> 0.1416 / 12 = 0.0118 Farad, or 11.8mF. That wont do though, as the
> capacitor voltage will be zero after dumping its charge.
>
> Assuming the gear changer mechanism is simply a MOSFET switch and some
> actuator coil,
Whoa! I have a Shimano system that is far more complicated than this
(it's full auto shifting) and that uses a tiny flat stepper motor with
utmost satisfaction. MOSFETS and coils are getting in a level of
chunkiness and complication I wouldn't want to wear, not to mention
clunky noises emanating from my bike while I'm cruising elegantly. I
imagine that the stepper motor on a Rohloff might have to be more
powerful than on the Shimano Nexus to account for the stiff outlier
like Chalo's box, but a stepper is a very reliable thingymabobsky
these days.
>it can likely withstand a large input voltage range for
> a short time. You could for instance, possibly, charge the cap to 18
> V and have it discharge to 6V during the gear change, but that doesn't
> allow for a bad change that takes 2-3 times longer than normal, or a
> worn and sticky mechanism. The capacitor would need to be probably 10
> times bigger.
>
> A 120mF electrolytic is going to be pretty big. Think of a 1F cap you
> can get for a car stereo is about as big as a coke can. It'll be of
> similar proportions size. Here's a 100mF 25V caphttp://www.tedss.com/item.asp?id=2020005300
>
> 3" diameter x 3.7" long. Now the battery system might actually be
> smaller, because you could keep a much smaller battery charged by the
> dynamo for ever.
Actually, there would have to be some sharing, with the cap and or
battery taking what's left after the running lights, maybe a GPS,
maybe charging a mobile phone, whatever the modern cyclist finds
indispensible. I don't think that cap is physically too big, though it
is certainly getting there.
> It wouldn't need to be anywhere near as big as
> theirs or the cap.
My objection to the battery is charging it, and its unreliability.
Jeff Liebermann was venting the other day about battery life, and it
was a horror story he told even where people have control of the
charge pattern. On the bike you're not going to have a lot of control
unless you go for complicated electronics, which kinda defeats the
purpose. On the other hand, my Shimano Cyber Nexus full auto system,
which doesn't even have a facility for external charging, always spun
up enough charge in a couple of revolutions of the wheel, and never
once ran out of juice.
> > "Strictly speaking, I suppose our system would work without the
> > battery but obviously you won't be able to change gears whilst at
> > standstill unless you have a huge capacitor in the system."
>
> > ***
>
> Ah ha.
>
> > I like the big capacitor better than a battery, simply because the cap
> > will be smaller if not necessarily lighter, and caps are always less
> > trouble than batteries.
>
> True, but you'll still need a rectifier and boost converter to get
> enough charge into a cap.
Thing is, I don't even have to design and develop an inverter/
regulator/charger, one is available from BUMM called the E-Werk and
there's even an optional storage device for delivery smoothing; I'm
heading there right now to discover whether it's a battery (likely as
it is flat) or a cap. And a dedicated type is promised from Edsan.
You understand, my interest isn't in electronically assisted shifting
as such. That's a trivial application of so much technology, of
interest mainly to the drop handlebar crowd, for whom it is a way of
fitting a Rohloff gearchanger under their hand (Rohloff only makes a
rotary control for mountain bar diameter, not drop bar). There might
be a bigger market there than I first thought, as this Edsan product
lets them keep up their heads when they run into the other cafe racers
with Dura-Ace Di2 fitted. My own interest is in going beyond that, in
turning the Rohloff into a fully automatic gearbox. I was very, very,
very impressed with how going from a manual Nexus to a full-auto Cyber
Nexus cut at least ten per cent off my average times over roads I rode
daily.
> JS.
>
> (I hope this wasn't too long for Ed.)
When you see them contribute something useful will be enough time to
wonder whether necessary information is too long for the little
losers. Don't hold your breath.
Certainly I appreciate even (perhaps especially) your remark "For a
capacitor, charge in coulombs q = CV", which might offend one of the
less secure professional engineer here. Saves me looking it up. And
worked examples are like gold in any field.
(PeteCresswell)
> I might be able to use
>the SHIFTEZY/hub dynamo/inverter as a shortcut to a *full auto* box by
>adding speed sensing electronics of my own.
Different strokes for different folks, I guess.
Having said that...
I've tried an auto-shifter bike and found it unpleasant to ride.
The problem is that when riding, you want different gears in
different situations regardless of crank RPMs.
Coming into rough pavement, for instance, you want to shift up to
get your weight off the saddle and then shift back down when the
pavement is smooth again.
Going up a long hill, you want to shift up 3-4 gears every so
often to get out of the saddle and give your butt a break.
Sometimes you just feel like spinning your brains out.... other
times you feel like slogging.
And so-on and so-forth...
--
PeteCresswell
James
Indeed they are reliable, provided they, like most electromechanical
parts exposed to the elements, are well sealed. (A stepper motor is
after all comprised of a few coils on the stator, and the controller
will no doubt use MOSFETs internally to drive the coils.)
> >it can likely withstand a large input voltage range for
> > a short time. You could for instance, possibly, charge the cap to 18
> > V and have it discharge to 6V during the gear change, but that doesn't
> > allow for a bad change that takes 2-3 times longer than normal, or a
> > worn and sticky mechanism. The capacitor would need to be probably 10
> > times bigger.
>
> > A 120mF electrolytic is going to be pretty big. Think of a 1F cap you
> > can get for a car stereo is about as big as a coke can. It'll be of
> > similar proportions size. Here's a 100mF 25V caphttp://www.tedss.com/item.asp?id=2020005300
>
> > 3" diameter x 3.7" long. Now the battery system might actually be
> > smaller, because you could keep a much smaller battery charged by the
> > dynamo for ever.
>
> Actually, there would have to be some sharing, with the cap and or
> battery taking what's left after the running lights, maybe a GPS,
> maybe charging a mobile phone, whatever the modern cyclist finds
> indispensible. I don't think that cap is physically too big, though it
> is certainly getting there.
A combination battery and capacitor then? Battery for bulk storage
and a cap for short duration high current loads perhaps?
> > It wouldn't need to be anywhere near as big as
> > theirs or the cap.
>
> My objection to the battery is charging it, and its unreliability.
Can't argue with that. I'm a battery hater. Unfortunately they often
become a necessary evil.
> Jeff Liebermann was venting the other day about battery life, and it
> was a horror story he told even where people have control of the
> charge pattern. On the bike you're not going to have a lot of control
> unless you go for complicated electronics, which kinda defeats the
> purpose. On the other hand, my Shimano Cyber Nexus full auto system,
> which doesn't even have a facility for external charging, always spun
> up enough charge in a couple of revolutions of the wheel, and never
> once ran out of juice.
It must be possible then for the Rohloff, though a bigger energy
storage device might be required.
> > > "Strictly speaking, I suppose our system would work without the
> > > battery but obviously you won't be able to change gears whilst at
> > > standstill unless you have a huge capacitor in the system."
>
> > > ***
>
> > Ah ha.
>
> > > I like the big capacitor better than a battery, simply because the cap
> > > will be smaller if not necessarily lighter, and caps are always less
> > > trouble than batteries.
>
> > True, but you'll still need a rectifier and boost converter to get
> > enough charge into a cap.
>
> Thing is, I don't even have to design and develop an inverter/
> regulator/charger, one is available from BUMM called the E-Werk and
> there's even an optional storage device for delivery smoothing; I'm
> heading there right now to discover whether it's a battery (likely as
> it is flat) or a cap. And a dedicated type is promised from Edsan.
More than likely a battery, and there goes your reliability. Maybe a
big enough cap and a tweak to their system to increase the voltage
enough would do it.
> You understand, my interest isn't in electronically assisted shifting
> as such. That's a trivial application of so much technology, of
> interest mainly to the drop handlebar crowd, for whom it is a way of
> fitting a Rohloff gearchanger under their hand (Rohloff only makes a
> rotary control for mountain bar diameter, not drop bar). There might
> be a bigger market there than I first thought, as this Edsan product
> lets them keep up their heads when they run into the other cafe racers
> with Dura-Ace Di2 fitted. My own interest is in going beyond that, in
> turning the Rohloff into a fully automatic gearbox. I was very, very,
> very impressed with how going from a manual Nexus to a full-auto Cyber
> Nexus cut at least ten per cent off my average times over roads I rode
> daily.
Does the full-auto Cyber Nexus simply shift so that you pedal in a
predetermined cadence range?
Regards,
James.
James
I can imagine that. Human engines need more logic in the gear
selection routine than just;
if cadence < 80 then shift smaller gear
else if cadence > 110 then shift bigger gear
Cheers,
James.
Jeff Liebermann
<fiul...@yahoo.com> wrote:
>> It wouldn't need to be anywhere near as big as
>> theirs or the cap.
>
>My objection to the battery is charging it, and its unreliability.
>Jeff Liebermann was venting the other day about battery life, and it
>was a horror story he told even where people have control of the
>charge pattern.
Batteries vent while I prefer to rant or pontificate.
Incidentally, charging a battery isn't much of a problem if you're
willing to tolerate perhaps 80% of capacity. The circuitry to do that
is almost trivial. It's charging to 100%, over varying temperatures,
that causes problems. The lower charge level also translates to a
longer battery life for Li-Ion. This is one case where a small drop
in efficiency, translated to a big improvement in reliability and
longevity.
>On the bike you're not going to have a lot of control
>unless you go for complicated electronics, which kinda defeats the
>purpose.
Electronics are getting simpler. What seems to be missed is that once
a microprocessor or PIC computing system is installed to provide the
basic function (shifting and charging), a wide array of other
computing intensive features and functions are easily added. For
example, some manner of energy monitor. Maybe a vibration analyzer,
or road surface logger (bumps per Km). The hard part is getting the
electronics initially justified. Everything after that is nearly
free.
There's been some capacitor and battery progress since I last came up
for air, most due to EV research. See:
<http://en.wikipedia.org/wiki/Electric_double-layer_capacitor>
The energy density (Watt-hrs per Kg) has improved on high end
supercaps and Li-Ion capacitors:
<http://en.wikipedia.org/wiki/Lithium_ion_capacitor>
While supercaps cost much more, they have the advantage of being able
to run them to total discharge. Do the same with most batteries, and
you have a dead battery. While supercaps may be larger than the
equivalent batteries, the energy density trends points to lighter
weight capacitor.
Would you believe 5000 Farads at 2.7V?
<http://www.nesscap.com/products_lineup.htm>
The energy stored in a cazapitor is:
Joules=0.5*Farads*Volts^2.
<http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capeng.html>
So, this cap can store 18,000 joules.
The cazapitor that James mentioned:
<http://www.tedss.com/item.asp?id=2020005300>
will do only 31 Joules. The limiting factor on the power available,
where:
Power = Joules / seconds = Watts
is the ESR (equivalent series resistance) of the cazapitor. Too high
and you can't discharge it fast enough to activate the solenoid that
crashes the gears. All the power is dissipated inside the cap, and
not in the load.
Since my math was totally wrong that last time I ranted on this
subject, and since I'm now recovering from a tooth extraction, could
someone please check my math and logic?
Incidentally, I once designed a wind up ticket printer using a
clockwork mainspring for energy storage. Such a contivance could be
fitted to the Rohloff hub to store sufficient mechanical energy to
perform a shift or two while not moving. Not a great solution, but
certainly simpler than generator, electronics, battery, and solenoid.
Hmmm... Vicodin is doing strange things to my imagination.
--
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
Andre Jute
> Per Andre Jute:
>
> > I might be able to use
> >the SHIFTEZY/hub dynamo/inverter as a shortcut to a *full auto* box by
> >adding speed sensing electronics of my own.
>
> Different strokes for different folks, I guess.
>
> Having said that...
>
> I've tried an auto-shifter bike and found it unpleasant to ride.
Which one?
> The problem is that when riding, you want different gears in
> different situations regardless of crank RPMs.
>
> Coming into rough pavement, for instance, you want to shift up to
> get your weight off the saddle and then shift back down when the
> pavement is smooth again.
>
> Going up a long hill, you want to shift up 3-4 gears every so
> often to get out of the saddle and give your butt a break.
>
> Sometimes you just feel like spinning your brains out.... other
> times you feel like slogging.
>
> And so-on and so-forth...
> --
> PeteCresswell
Nobody in his right mind designs an autobox without a manual override
for those occasions when someone wants to be a bolshie human.
Andre Jute
> Does the full-auto Cyber Nexus simply shift so that you pedal in a
> predetermined cadence range?
It doesn't even measure cadence. It has a desired effort setting which
is about the equivalence of cadence. In addition it has a number four
programs, one of which is manual control, one of which is sporting
(cuts out first gear), one standard, and one little old lady mode
which hangs on to the lower gears longer, all modes available by
punching a button. There's a complete description and photographs
here:
http://members.multimania.co.uk/fiultra/BICYCLE%20Trek%20Navigator%20L700%20Smover.html
Andre Jute
Not everything in materials is dreamt of in Timoshenko
Andre Jute
> Human engines need more logic in the gear
> selection routine than just;
>
> if cadence < 80 then shift smaller gear
> else if cadence > 110 then shift bigger gear
Why? All that is required is a few different programmes available at
the press of a button. You'll be surprised how quickly the manual
override becomes irrelevant. --AJ
James
> On Wed, 25 Aug 2010 16:56:29 -0700 (PDT), Andre Jute
>
Yup. Super caps might be the go, though did you see the size of the
one you suggest? 165x60x60mm, and only 2.7V and weighs nearly 1kg, so
you might want to reconsider the part.
> The cazapitor that James mentioned:
> <http://www.tedss.com/item.asp?id=2020005300>
> will do only 31 Joules. The limiting factor on the power available,
> where:
> Power = Joules / seconds = Watts
> is the ESR (equivalent series resistance) of the cazapitor. Too high
> and you can't discharge it fast enough to activate the solenoid that
> crashes the gears. All the power is dissipated inside the cap, and
> not in the load.
Either would do in this regard. Electrolytics or supercaps can both
have very low ESR, in the order of a 10s of mOhms.
> Since my math was totally wrong that last time I ranted on this
> subject, and since I'm now recovering from a tooth extraction, could
> someone please check my math and logic?
Sounds fair to me.
> Incidentally, I once designed a wind up ticket printer using a
> clockwork mainspring for energy storage. Such a contivance could be
> fitted to the Rohloff hub to store sufficient mechanical energy to
> perform a shift or two while not moving. Not a great solution, but
> certainly simpler than generator, electronics, battery, and solenoid.
>
> Hmmm... Vicodin is doing strange things to my imagination.
Good luck with that tooth.
Cheers,
James.
Andre Jute
two years of surgery in my mouth every six weeks.
Still reading. A fast-charging cap would be able to grab whatever the
dynamo produces that isn't required elsewhere. I'm not sure cutting
edge technology is necessary, though. It seems to the common cap in a
standlight like the BUMM Cyo charges fast enough, and I have good
experience in valve amps with batteries in bias circuits trickle-
charging essentially forever.
Andre Jute
Sometimes I sits and thinks, and sometimes I just sits
On Aug 26, 2:34 am, Jeff Liebermann <je...@cruzio.com> wrote:
> On Wed, 25 Aug 2010 16:56:29 -0700 (PDT), Andre Jute
>
> Santa Cruz CA 95060http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558
Jeff Liebermann
<fiul...@yahoo.com> wrote:
>Thanks to the Vikodan Kid. Sorry. I know how you feel; I'm just out of
>two years of surgery in my mouth every six weeks.
Ouch. Sounds like no fun. I'm doing quite well. The few problems
I've had were all due to fillings done when I was a teenager. At
about 21, I decided that tooth paste was a bad idea, and stopped
brushing with the stuff. Both my parents lost all their teeth by age
50. I've had one root canal and cap, all the wisdom teeth pulled, and
nothing else. Not too bad since the last time I saw a dentist was 17
years ago. Moral...The orthodoxy isn't always right.
>Still reading. A fast-charging cap would be able to grab whatever the
>dynamo produces that isn't required elsewhere.
There's also the motor/generator in the seat tube idea.
<http://www.gruberassist.com/english/product/product-description/>
Another Vicodin inspired idea. Since your speedhub equipped bicycle
has a fixed chain, it might be possible to attach a small sprocket
gear, clutch, and generator to the chain. The generator gets its
drive when you pedal only in reverse (might as well do something
useful instead of just coasting).
>I'm not sure cutting
>edge technology is necessary, though.
Exotic technology always fails in exotic ways. Keep it simple (and
cheap).
>It seems to the common cap in a
>standlight like the BUMM Cyo charges fast enough,
I'm not familiar with the unit, but if it can run a bicycle light, it
can probably charge a capacitor that will close a solenoid for one or
two shifts. I need specs and numbers to be sure.
>and I have good
>experience in valve amps with batteries in bias circuits trickle-
>charging essentially forever.
Charging? If your thermionic tube/valve is drawing or sourcing grid
current, you're doing something wrong. I was using mercury batteries
for negative grid bias many years ago. They would last literally
forever. Also for negative gate bias for GaAs FET rx amps, where
applying power in the wrong order, will the vaporize the FET.
Vicodin seems to be working well. I feel no pain, but no brain. All
I can do without a brain is post rants to Usenet.
--
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