Genset voltage reg: capacitor vs. AVR

[Existential Angst]

What are the pro's/cons of each?

One pro for caps is that they are cheaper! The AVR ditty for my unit would
cost another near-$400.
The pro for AVR is, presumably, much tighter voltage regulation with load.

But mebbe AVR has its limits ito ruggedness?

The voltage swing on my genset is 250 - 230 V, 0-50 A. Units with AVR
claim 1-2% regulation.

Should I spring for the AVR? If a major outtage occurs, I'll be running cnc
equpment from it.
--
EA

[Pete S]

I don't understand your question.
If you mean "capacitors" when you say "caps", I don't know how they would
deal with output voltage regulation in any meaningful way.
What kind, model and serial number of genset do you have that currently has
no voltage regulation built in to it?

Pete Stanaitis
----------------

[tra...@optonline.net]

I think he's saying he has a cheap generator that uses
a cap for voltage regulation. They apparently do that by using
a cap in conjuction with the power source for excitation.

But a better question might be
why would someone living in NYC, who has a critical need
to run CNC eqpt during a major power outage, be concerned
about spending $400 for decent voltage regulation? You think
that would have been in the decision for the generator from
the start.

And how could anyone forecast what regulation is required,
what the possible voltage swings might be, without knowing
what all the actual loads are, what their tolerance is, etc?

[Existential Angst]

"Pete S" <sp...@baldwin-telecom.net> wrote in message
news:1_OdnUJP--8zsr3M...@bright.net...

>I don't understand your question.
> If you mean "capacitors" when you say "caps", I don't know how they would
> deal with output voltage regulation in any meaningful way.

Ditto. ergo my Q. I guess they must in some fashion, just like you balance
rpc's with caps.

> What kind, model and serial number of genset do you have that currently
> has no voltage regulation built in to it?

http://www.generatorsales.com/order/Honda-16kw-Propane-Generator.asp?page=H04599
modified for tri-fuel.

It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps
down to zero amps.
If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but
it's not 1% either.

Assume no electrical-type regulation at all. There is something between the
generator itself and the gas engine that ups fuel flow with load,
maintaining a semi-constant voltage. An AVR sharpens this up.

I don't quite understand how this works, and part of the intent of Q was to
shed some light on this.

I also figgered that if the feedback between generator and engine was good
enough, AVR wouldn't be needed.
So basically I"m curious about the design of these things.
--
EA



> Pete Stanaitis
> ----------------
>
>
>
>

[Robert]

On Feb 17, 8:49 am, "Existential Angst" <fit...@optonline.net> wrote:
> "Pete S" <sp...@baldwin-telecom.net> wrote in message
>
> news:1_OdnUJP--8zsr3M...@bright.net...
>
> >I don't understand your question.
> > If you mean "capacitors" when you say "caps", I don't know how they would
> > deal with output voltage regulation in any meaningful way.
>
> Ditto. ergo my Q. I guess they must in some fashion, just like you balance
> rpc's with caps.
>
> > What kind, model and serial number of genset do you have that currently
> > has no voltage regulation built in to it?
>

> http://www.generatorsales.com/order/Honda-16kw-Propane-Generator.asp?...

> modified for tri-fuel.
>
> It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps
> down to zero amps.
> If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but
> it's not 1% either.
>
> Assume no electrical-type regulation at all. There is something between the
> generator itself and the gas engine that ups fuel flow with load,
> maintaining a semi-constant voltage. An AVR sharpens this up.
>
> I don't quite understand how this works, and part of the intent of Q was to
> shed some light on this.
>
> I also figgered that if the feedback between generator and engine was good
> enough, AVR wouldn't be needed.
> So basically I"m curious about the design of these things.
> --
> EA
>
> > Pete Stanaitis
> > ----------------

I thought that it was a possibly that you had heard
of a "capacitor regulator' that I haven't, after 35
years as an electronics design engineer. So I
googled the subject and was unable to come up
with a single circuit/instance where a capacitive
system was used as a regulator....

I have the background to comment on the subject,
so if you will provide a website that comments
on how a capacitor or "capacitive circuit" can
regulate the output of a genset, I will study it
and give you an opinion, which, obviously you can
accept or reject....

I don't post this to insult you, but I really don't
see what you are asking ..

[Existential Angst]

<tra...@optonline.net> wrote in message
news:1e7e12fc-6f67-4e24...@z9g2000vbx.googlegroups.com...

On Feb 16, 8:17 pm, "Pete S" <sp...@baldwin-telecom.net> wrote:
> I don't understand your question.
> If you mean "capacitors" when you say "caps", I don't know how they would
> deal with output voltage regulation in any meaningful way.
> What kind, model and serial number of genset do you have that currently
> has
> no voltage regulation built in to it?
>
> Pete Stanaitis
> ----------------

I think he's saying he has a cheap generator that uses
a cap for voltage regulation. They apparently do that by using
a cap in conjuction with the power source for excitation.

================================================

Except it's not so cheap. Which is why I was disappointed in the
regulation.
AVR IS available for the unit, they just chose to use caps..

But a better question might be
why would someone living in NYC, who has a critical need
to run CNC eqpt during a major power outage, be concerned
about spending $400 for decent voltage regulation? You think
that would have been in the decision for the generator from
the start.

=============================================

I thought it did have AVR, and the point was, which you of course missed (in
your premature judgmental fervor), was *how much* better can AVR be expected
to improve things.... more of a general query as to how these things work.

And how could anyone forecast what regulation is required,
what the possible voltage swings might be, without knowing
what all the actual loads are, what their tolerance is, etc?

=================================================

That's the mfr's job. I in fact DID measure these things, whose values I
gave in the OP.

What size is YOUR generator, what fuel is used, and how well regulated is
it?
And what do you do about the noise? Or do you just let your neighbors
suffer?? lol
--
EA

[Ed Huntress]

Without following this thread, it seems to me that he's looking at a
filter circuit for suppressing voltage spikes rather than a voltage
regulator.

I'll leave it to you to comment.

--
Ed Huntress

[Scott Dorsey]

tra...@optonline.net <tra...@optonline.net> wrote:
>
>I think he's saying he has a cheap generator that uses
>a cap for voltage regulation. They apparently do that by using
>a cap in conjuction with the power source for excitation.

I'm not sure how that works.

The original AC voltage regulation system, which I think is called a Tillen
regulator, and dates back to the 19th century, involves a buzzer that
produces a square wave whose duty cycle is inversely proportional to the
output voltage of the generator. This is integrated by a capacitor into
a voltage that is inversely proportional to the output and that drives the
field coil. This is how automotive alternators used to work until the
seventies.

(There is another method used with big generators that involves a DC
motor generator set used to regulate the field coil, but we are talking
small gensets here.)

Anyway, the Tillen regulator is history and as far as I know nobody is
using it today. Instead they use a solid state circuit whose output
voltage is inversely proportional to the AC input voltage. Early on
these used SCRs that acted as switching devices more or less like the
Tillen mechanism, but by the 1970s they were mostly using big bipolar
transistors. This is what I think the original poster is calling an
"AVR" and it's pretty much how regular constant-speed AC generators work
today.

Now.... the interesting thing is that today we have a whole new breed
of generators which are not constant speed. They generate AC, which is
rectified and then used to power an inverter that creates constant
frequency AC. This means the engine throttle can be adjusted to regulate
voltage as well as the field coil... and it means the engine is throttled
way back where it is quiet when there is little load and opened up all
the way when there is more load. There's a lot more stuff inside the box
to go wrong and some of the inverters are kind of crappy (although I am
really amazed at how good a waveform and how little RF noise we get from
the Honda 2000i), so repair and diagnosis is a little trickier.

But if I were buying a baby generator (sub 5KVA) today, I would definitely
go the inverter route. In the 5-20 KVA range it would depend.

>But a better question might be
>why would someone living in NYC, who has a critical need
>to run CNC eqpt during a major power outage, be concerned
>about spending $400 for decent voltage regulation? You think
>that would have been in the decision for the generator from
>the start.

Personally, if I were running CNC equipment, I'd get out of NYC as fast as
possible and get to a place with better support for manufacturing and lower
tax rates...
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Existential Angst]

"Robert" <jungl...@hotmail.com> wrote in message
news:243a8c5a-6cdd-40c3...@j4g2000vby.googlegroups.com...

OK.....

I am actually reciting what the company told me.
Apropos of your comment (and Pete's confusion, as well), what I think they
actually meant was that the caps are used to TUNE or balance the system,
somewhat like you would the legs of a 3 ph rotary converter -- which I do
all the time.

As I mentioned above, the "first stage" of regulation is accomplished via
some linkage between the generator and the motor, as in gas powered
welders -- which I've always been curious about how that works.
AVR would then seem to improve this.

Not sure how all this occurs, just exploring the idea of tighter regulation.

Part of my Q was a suspicion that an AVR proly regulates voltage more
tightly, but perhaps at the expense of raw current flow. Iow, I might get
"better" juice, just less of it. Just wondering.....
--
EA

[Existential Angst]

"Scott Dorsey" <klu...@panix.com> wrote in message
news:kfqrqt$e26$1...@panix2.panix.com...

Which is what cars do, right?

In generators, I think they call it automatic idle, in the better units.

There's a lot more stuff inside the box
> to go wrong and some of the inverters are kind of crappy (although I am
> really amazed at how good a waveform and how little RF noise we get from
> the Honda 2000i), so repair and diagnosis is a little trickier.
>
> But if I were buying a baby generator (sub 5KVA) today, I would definitely
> go the inverter route. In the 5-20 KVA range it would depend.

There's also the issue of "true sine" vs. std inverter output. True sine is
sig'ly more expensive.

>
>>But a better question might be
>>why would someone living in NYC, who has a critical need
>>to run CNC eqpt during a major power outage, be concerned
>>about spending $400 for decent voltage regulation? You think
>>that would have been in the decision for the generator from
>>the start.
>
> Personally, if I were running CNC equipment, I'd get out of NYC as fast as
> possible and get to a place with better support for manufacturing and
> lower
> tax rates...

AMEN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Hopefullyl they'll let me into VanCouver, BC, Canada.... LOL

fuknBloomberg has no sympathy for people unwilling/unable to spend $1 mil on
a 1 BR apt, whose rent (before he and Guiliani gutted rent control) was
proly $500/mo.

"Buying" apts. is essentially mega "key money", which is illegal.
But when sed key money allows you to "flip" a hot potato to some other
sucker, which generates all kinds of minicipal revenue, then I guess it's
ok.....

Parts of NYC used to be machining meccas, partic. in the small parts
industry (spring-making, lighting, for example), and in knitting. Pre-1990,
parts of Brooklyn, Queens were the knitting capital of the world, I'm told,
with a large machining infrastructure (mom&pop machining, btw) to make the
many *very* intricate parts that would wear in the needle/knitting process.
--
EA

[tra...@optonline.net]

> see what you are asking ..- Hide quoted text -
>
> - Show quoted text -

It's not hard to find discussion of caps as voltage
regulators. Here's an example, about a third of the
way down in this thread:

http://www.smokstak.com/forum/showthread.php?t=16338

Seems like a pretty crappy thing to find though on a
$3000 generator.

[Jim Wilkins]

"Existential Angst" <fit...@optonline.net> wrote in message
news:5120f2c2$0$24765$607e...@cv.net...

>
> Part of my Q was a suspicion that an AVR proly regulates voltage
> more tightly, but perhaps at the expense of raw current flow. Iow,
> I might get "better" juice, just less of it. Just wondering.....
> --
> EA

For lower power demands a high-end APC SmartUPS can regulate the AC
output if the line goes high or low. I got one free with bad, swollen
batteries. It works without them, or with external batteries plugged
into the rear connector.
http://www.apcmedia.com/salestools/ASTE-6Z8L9X_R0_EN.pdf

[Existential Angst]

<tra...@optonline.net> wrote in message
news:d63af4d0-9b64-480d...@cd3g2000vbb.googlegroups.com...

==================================================

Inneresting thread. But I think one can conclude that caps are not
regulating, they are tuning, balancing. with mebbe an itty bitty bit of
regulation as a perk to tuning.

But if you follow the op Jim McIntyre, what his cap(s) did was raise/lower
the voltage. The unit itself, apparently pretty high quality, seems to have
had inherently good regulation between the generator itself and the motor.
Anthony W. commented that

"It sounds as if Kubota did their homework on the winding ratios in your
set. As you found, the cap value isn't too critical in a "good" set within a
reasonable range. Problems usually only show up when a certain critical cap
value is exceeded.
Also in the case of a non-linear load such as a switching power supply,(if
you run your computer off of one) plug an incandesent lamp or two in as
well. I don't know that it would hurt anything, but the waveform looks
"slanted" on a 'scope when only a switching-type load is applied.
The only troubles I have had with the several old Cap regulated sets I have
owned are bearing issues and the cap going "open". "

And the quality of the linkage between the generator/engine was proly
superior.

Notice, tho, that when McIntyre increased his cap size, the voltage
regulation went from about 1% to 2%.
Note that in mine, a much larger unit, the regulation, from midpoint, is 4%
right now -- not terrible terrible, but again, not 1%.
--
EA

[tra...@optonline.net]

On Feb 17, 9:49 am, "Existential Angst" <fit...@optonline.net> wrote:
> "Pete S" <sp...@baldwin-telecom.net> wrote in message
>
> news:1_OdnUJP--8zsr3M...@bright.net...
>
> >I don't understand your question.
> > If you mean "capacitors" when you say "caps", I don't  know how they would
> > deal with output voltage regulation in any meaningful way.
>
> Ditto.  ergo my Q.  I guess they must in some fashion, just like you balance
> rpc's with caps.
>
> > What kind, model and serial number  of genset do you have that currently
> > has no voltage regulation built in to it?
>

> http://www.generatorsales.com/order/Honda-16kw-Propane-Generator.asp?...

> modified for tri-fuel.
>
> It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps
> down to zero amps.
> If you at mid-load it's 240 V,  that's +/-10V, which is not terrible, but
> it's not 1% either.
>
> Assume no electrical-type regulation at all.  There is something between the
> generator itself and the gas engine that ups fuel flow with load,
> maintaining a semi-constant voltage.

That would be the mechanical engine governor.

An AVR sharpens this up.

Yes

>
> I don't quite understand how this works, and part of the intent of Q was to
> shed some light on this.

See my other post to a discussion.

>
> I also figgered that if the feedback between generator and engine was good
> enough, AVR wouldn't be needed.
> So basically I"m curious about the design of these things.
> --
> EA
>

Do you realize what you got for $2800? They take a Honda
engine and bolt it on to some generator made by someone
else. Perhaps you can shed light on to who that someone
else is, but given that it uses a cap for voltage regulation,
I would not be surprised that it's a cheap Chinese one.
Then they take pretty pictures of the thing with Honda showing
all over in the pretty pics and a lot of people make the
assumption that they are buying a Honda generator.
I don't believe that is the case.

Further arousing suspicion is that they claim it's 15KW.
Then if you read the specs, it says it's rated at 13.5KW
continuous. Then they say it has a 50 amp main
breaker, which equates to 12KW, in my world.

You with me so far? Further arrousing suspicion, they
quote fuel consumption in gallons, ie it's based on running
the engine on gas. So, next, let's look at the spec for
a Honda GX690. It says it produces 22hp running gasoline.
I'm no expert in conversions from gasoline to nat gas, but
AFAIK, when you run a gasoline engine on nat gas, you
have about 15% less energy output. Maybe someone has
the exact number. That means you really have about an
18hp engine.

I've looked into generators a bit and what it takes to
power them. I don't think you can get 15KW out of an
18hp engine. A Generac 12KW unit for example, uses
a 26hp engine.

Just some more things to think about.

[jim beam]

it's possible they're being used for power factor correction rather than
regulation. pfc gets to be important with some reactive loads.

>
> I have the background to comment on the subject,
> so if you will provide a website that comments
> on how a capacitor or "capacitive circuit" can
> regulate the output of a genset, I will study it
> and give you an opinion, which, obviously you can
> accept or reject....
>
> I don't post this to insult you, but I really don't
> see what you are asking ..
>

--
fact check required

[Existential Angst]

<tra...@optonline.net> wrote in message
news:a2f868c5-dcae-4e56...@k14g2000vbv.googlegroups.com...

On Feb 17, 9:49 am, "Existential Angst" <fit...@optonline.net> wrote:
> "Pete S" <sp...@baldwin-telecom.net> wrote in message
>
> news:1_OdnUJP--8zsr3M...@bright.net...
>
> >I don't understand your question.
> > If you mean "capacitors" when you say "caps", I don't know how they
> > would
> > deal with output voltage regulation in any meaningful way.
>
> Ditto. ergo my Q. I guess they must in some fashion, just like you balance
> rpc's with caps.
>
> > What kind, model and serial number of genset do you have that currently
> > has no voltage regulation built in to it?
>
> http://www.generatorsales.com/order/Honda-16kw-Propane-Generator.asp?...
> modified for tri-fuel.
>
> It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+
> amps
> down to zero amps.
> If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but
> it's not 1% either.
>
> Assume no electrical-type regulation at all. There is something between
> the
> generator itself and the gas engine that ups fuel flow with load,
> maintaining a semi-constant voltage.

That would be the mechanical engine governor.

====================================================

I sure would like to know the details on how those work.

An AVR sharpens this up.

Yes


>
> I don't quite understand how this works, and part of the intent of Q was
> to
> shed some light on this.

See my other post to a discussion.


>
> I also figgered that if the feedback between generator and engine was good
> enough, AVR wouldn't be needed.
> So basically I"m curious about the design of these things.
> --
> EA
>


Do you realize what you got for $2800? They take a Honda
engine and bolt it on to some generator made by someone
else. Perhaps you can shed light on to who that someone
else is, but given that it uses a cap for voltage regulation,
I would not be surprised that it's a cheap Chinese one.
Then they take pretty pictures of the thing with Honda showing
all over in the pretty pics and a lot of people make the
assumption that they are buying a Honda generator.
I don't believe that is the case.

=====================================================

McCaulte (sp?) makes the generator.

And yes, they mix'n'match.... but presumably they do it pretty well, altho
I got a li'l short-shrifted on the AVR deal....
I don't know that they are being misleading, as much as emphasizing the
Honda part.... LOL
Thin line, admittedly.

Further arousing suspicion is that they claim it's 15KW.
Then if you read the specs, it says it's rated at 13.5KW
continuous.

=============================================

This is typical. Generac does this.

Then they say it has a 50 amp main
breaker, which equates to 12KW, in my world.

======================================

Yeah, I noticed that. And they trip fast, too!
I may put in my own 50 A slower-tripping or even 60 A breakers.

You with me so far? Further arrousing suspicion, they
quote fuel consumption in gallons, ie it's based on running
the engine on gas. So, next, let's look at the spec for
a Honda GX690. It says it produces 22hp running gasoline.
I'm no expert in conversions from gasoline to nat gas, but
AFAIK, when you run a gasoline engine on nat gas, you
have about 15% less energy output. Maybe someone has
the exact number. That means you really have about an
18hp engine.

===============================================

Again, par for the course. I simply went for the most watts. Those watts
will be similarly de-rated in most scenarios, so I just went with the
biggest number.

I've looked into generators a bit and what it takes to
power them. I don't think you can get 15KW out of an
18hp engine. A Generac 12KW unit for example, uses
a 26hp engine.

================================================

Oh, but I did get very nearly the full 13.5 continuous (on gasoline), and
proly could have gotten sig. more. I'll have to jump/replace the breaker,
tho. Already at near-full load, it started a 26 gal compressor, w/ nary a
hiccup.

A 26 hp engine for 12 kW is suspect as well, from two povs:
First, I suspect Generac hp is like Sears hp.
Second, if it IS 26 hp, yer just sipping lots more gas.... which was one of
the things I was going to discuss in my upcoming Generator Manifesto.....
big-azz generators, in no-load conditions, are not economical.

I really couldn't find much better overall bang fer the buck, watt-wise.
The Honda motor is a plus, and the unit is VERY compact.
Generacs are big and complicated. OK, I spose, for the home-moaner who
justs likes to dial the telephone when sumpn goes wrong, and from what I've
read about generac, they will be using their telephone fairly often.

Here's some of my take on this:

I would recommend the Sam's club 8,750 W blackmax, at $999, for most people
with more than the basic needs. You can get it modified for tri-fuel, and
the link I provided sells a modified blackmax for $1600 -- about a $200-$400
preimum over what you would pay if you did it yourself, but with a lot less
headache, and somewhat of a guarantee. The blackmax also has AVR, iirc, and
performed quite well, before it grew feet.

My unit does not come with a gas tank, but which is actually an advantage,
imo, because you just drop the genset's hose down any gas can (or your car's
gas tank, if you can snake it in), and Wala, gasoline power.

I went for the 15 kW unit, in the second go-around, for many of the reasons
you stated:
By the time you get done de-rating for whatever whatever reasons, you
have a lot less than when you started, so I figgered I'd just double the
size from the gitgo.

Really a lot of g-d work. The other bottom line to all this is that unless
you have a water-cooled 4 cylinder unit, you gotta simply build a separate
sound-proofed shed for these noise buckets.
A lot of my work so far went in to testing, given my cnc liabilities. So
far so good, but really a pita -- for sumpn I may NEVER use.
--
EA

[tra...@optonline.net]

On Feb 17, 11:23 am, "Existential Angst" <fit...@optonline.net> wrote:
> <trad...@optonline.net> wrote in message

Find the parts diagram for the Honda engine. They typically
rely on centrifugal force. If the engine starts to slow down, the
drop in centrifugal force causes movement of linkage connected
to the carb throttle.

> An AVR sharpens this up.
>
> Yes
>
>
>
> > I don't quite understand how this works, and part of the intent of Q was
> > to
> > shed some light on this.
>
> See my other post to a discussion.
>
>
>
> > I also figgered that if the feedback between generator and engine was good
> > enough, AVR wouldn't be needed.
> > So basically I"m curious about the design of these things.
> > --
> > EA
>
> Do you realize what you got for $2800?  They take a Honda
> engine and bolt it on to some generator made by someone
> else.  Perhaps you can shed light on to who that someone
> else is, but given that it uses a cap for voltage regulation,
> I would not be surprised that it's a cheap Chinese one.
> Then they take pretty pictures of the thing with Honda showing
> all over in the pretty pics and a lot of people make the
> assumption that they are buying a Honda generator.
> I don't believe that is the case.
> =====================================================
>
> McCaulte (sp?) makes the generator.

Meccalte. They are an Italian company. You can
buy one of their 12-15KW generator heads for about $800.
Not sure what kind of voltage regulation you get for that price.
Find the model, look up the spec sheet. I'll bet it says you
need 25hp or so to get full power out of it. And I doubt an
engine rated at 22hp on gasoline is capable of that running
on natural gas. Have you tried running it at full load on natural
gas?

>
> And yes, they mix'n'match....  but presumably they do it pretty well, altho
> I got a li'l short-shrifted on the AVR deal....

There isn't much to it. The engines and generators have
common mounting standards that just bolt together.

>
> Oh, but I did get very nearly the full 13.5 continuous (on gasoline), and
> proly could have gotten sig. more. I'll have to jump/replace the breaker,
> tho.  Already at near-full load, it started a 26 gal compressor, w/ nary a
> hiccup.
>
> A 26 hp engine for 12 kW is suspect as well, from two povs:
> First, I suspect Generac hp is like Sears hp.

It's not Generac specific. Take a look at what Meccalte or other
generator head manufacturers spec for power required to support
12KW, 15KW, etc.

> Second, if it IS 26 hp, yer just sipping lots more gas....  which was one of
> the things I was going to discuss in my upcoming Generator Manifesto.....
> big-azz generators, in no-load conditions, are not economical.

You can't have it both ways. Well,, actually you can, if you're
willing
to pay for it. You can buy an inverter based generator. That
completely
decouples the rotational speed from the frequency. That way, the
engine can run at low RPMs with low loads. It makes them very
fuel efficient at lower loads and also quiet. But you'll pay $4,000
for maybe 3000 watts.

>
> I really couldn't find much better overall bang fer the buck, watt-wise.
> The Honda motor is a plus, and the unit is VERY compact.
> Generacs are big and complicated.  OK, I spose, for the home-moaner who
> justs likes to dial the telephone when sumpn goes wrong, and from what I've
> read about generac, they will be using their telephone fairly often.

With a 5 to 7KW generator you can easily run a big house.
Except for central AC and electric hot water. On a cheapo
5KW generator we ran 4 refigerator/freezers, two gas
furnaces, 2 gas power vented water heaters, plus some
lights. That was for two large houses.

But if you need to run a machine shop, then it's a whole
different ball game.

>
> Here's some of my take on this:
>
> I would recommend the Sam's club 8,750 W blackmax, at $999, for most people
> with more than the basic needs.  You can get it modified for tri-fuel, and
> the link I provided sells a modified blackmax for $1600 -- about a $200-$400
> preimum over what you would pay if you did it yourself, but with a lot less
> headache, and somewhat of a guarantee.  The blackmax also has AVR, iirc, and
> performed quite well, before it grew feet.

You can get a Briggs and Stratton for the same price. It's probably
made in China, but at least B&S knows about engines, knows about
QC, has a long track record and you know where to find them. Who
is Blackmax? Probably a sticker and label on a China generic.

>
> My unit does not come with a gas tank, but which is actually an advantage,
> imo, because you just drop the genset's hose down any gas can (or your car's
> gas tank, if you can snake it in), and Wala, gasoline power.
>
> I went for the 15 kW unit, in the second go-around, for many of the reasons
> you stated:
>     By the time you get done de-rating for whatever whatever reasons, you
> have a lot less than when you started, so I figgered I'd just double the
> size from the gitgo.
>
> Really a lot of g-d work.  The other bottom line to all this is that unless
> you have a water-cooled 4 cylinder unit, you gotta simply build a separate
> sound-proofed shed for these noise buckets.
> A lot of my work so far went in to testing, given my cnc liabilities.  So
> far so good, but really a pita -- for sumpn I may NEVER use.
> --
> EA
>

> Just some more things to think about.- Hide quoted text -

[jon_banquer]

On Feb 17, 8:23 am, "Existential Angst" <fit...@optonline.net> wrote:
> <trad...@optonline.net> wrote in message

It seems it's often impossible to buy the right package for what
someone wants.

An example is an air compressor. I don't intend to run my air
compressor day in and day out so I don't have the need for a very
heavy duty dual stage air compressor pump like this one:

http://www.northerntool.com/shop/tools/product_42535_42535

I'd like this air compressor pump because it's got an 18 CFM rating at
90 PSI and it's got a decent price.

http://www.northerntool.com/shop/tools/product_200387235_200387235

I'd like this motor:

http://www.northerntool.com/shop/tools/product_200306765_200306765

When I try an find a reasonably priced horizontal air tank I'm fucked.
Prices are insane. Looks like my only choice will be to buy a used
horizontal air tank.

[The Daring Dufas]

I believe you got your timeline a bit off on automotive generators. My
63 Dodge had an "alternator" with a transistorized voltage regulator. My
family had a 55 Chrysler which had a "generator" and electromechanical
voltage regulator. I do believe the GM cars from the 70's had the solid
state voltage regulator built into the alternator itself. ^_^

TDD

[Existential Angst]

"jon_banquer" <jonba...@yahoo.com> wrote in message
news:58fe8a09-25c9-468b...@y2g2000pbg.googlegroups.com...

============================================

Amazing how that works.... in almost everything! From vitamins to cars to
cnc to real estate.....
Canada here I come.....

An example is an air compressor. I don't intend to run my air
compressor day in and day out so I don't have the need for a very
heavy duty dual stage air compressor pump like this one:

http://www.northerntool.com/shop/tools/product_42535_42535

I'd like this air compressor pump because it's got an 18 CFM rating at
90 PSI and it's got a decent price.

http://www.northerntool.com/shop/tools/product_200387235_200387235

========================================================

I'd be careful of Northern Tool. They are not above shenannigans.
I'd look at the displacement of the pistons, and try to guestimate the rpm,
and match that to cfm claims of similar sized compressors. Ahm no 'spert,
but 18 cfm at 90 psi seems pretty substantial. I'da thought more like 5 or 8
for that size.
I'd check out comparable sized Quincy's, or other reputable brands, and see
what they list.

The husky compressor is surprisingly civilized.

I'd like this motor:

http://www.northerntool.com/shop/tools/product_200306765_200306765

When I try an find a reasonably priced horizontal air tank I'm fucked.
Prices are insane. Looks like my only choice will be to buy a used
horizontal air tank.

============================================================

Well, mixing/matching is not a bad idea, and proly a really good one. Tanks
are tanks, motors are motors, so really what you want are a nice (quiet)
'pressor head, and a good regulator, with separate set points for
cut-in/cut-out, which bigbox stuff doesn't have.

Also, recall from a previous discussion that a big tank will help compensate
for smaller compressor size, and that instead of one big tank, a bunch of
small ones are the same as one big one, and a lot more manageable. I have a
bunch connected together, each one separately valved. You don't even need
the motor/'pressor mounted on a tank, per se.
I've even got some BBQ propane tanks I want to hook in, but goddamm, do they
make it difficult to remove dat stuff in the 3/4 neck. Also, there's no
drain, altho they are small enough you could put the drain on top, and just
tilt it to drain it.
--
EA

[jon_banquer]

On Feb 17, 9:40 am, "Existential Angst" <fit...@optonline.net> wrote:
> "jon_banquer" <jonbanq...@yahoo.com> wrote in message

For some reason I never thought about doing that. Thanks for bringing
it up! Being able to move this setup around easily is going to be a
factor. Also, this would allow me to go with a vertical tanks.

[The Daring Dufas]

I don't think it would be too far out in space to think of the capacitor
regulated generator as being related to a ferroresonant transformer or a
CVT, Constant Voltage Transformer. The only difference
is there is a mechanically rotating winding. ^_^

TDD

[Michael A. Terrell]

The Daring Dufas wrote:
>
> I don't think it would be too far out in space to think of the capacitor
> regulated generator as being related to a ferroresonant transformer or a
> CVT, Constant Voltage Transformer. The only difference
> is there is a mechanically rotating winding. ^_^

A CVT requres a sepereate winding to resonate with the cap. If it
were part of an active circuit, the Q would be too low to do any good.

[The Daring Dufas]

I did write "related". ^_^

TDD

[Transition Zone]

On Feb 17, 9:32 am, "trad...@optonline.net" <trad...@optonline.net>
wrote:

> On Feb 16, 8:17 pm, "Pete S" <sp...@baldwin-telecom.net> wrote:
>
> > I don't understand your question.
> > If you mean "capacitors" when you say "caps", I don't  know how they would
> > deal with output voltage regulation in any meaningful way.
> > What kind, model and serial number  of genset do you have that currently has
> > no voltage regulation built in to it?
>
> > Pete Stanaitis
> > ----------------
>
> I think he's saying he has a cheap generator that uses
> a cap for voltage regulation.  They apparently do that by using
> a cap in conjuction with the power source for excitation.
>
> But a better question might be
> why would someone living in NYC, who has a critical need
> to run CNC eqpt during a major power outage, be concerned
> about spending $400 for decent voltage regulation?  You think
> that would have been in the decision for the generator from
> the start.

Many of the transformers and other circuitry in lower manhattan are
still being put back up. Most of that stuff was underwater (salt
water) south of 32nd street. I wonder if he's reparing generators.
I'd repair the diesel ones. There'd be more money in those, but stick
to repair manuals and their one eight hundred tech numbers.

[Transition Zone]

On Feb 17, 10:09 am, klu...@panix.com (Scott Dorsey) wrote:

> trad...@optonline.net <trad...@optonline.net> wrote:
>
> >I think he's saying he has a cheap generator that uses
>> a cap for voltage regulation. They apparently do that by using
> > a cap in conjuction with the power source for excitation.
>
> I'm not sure how that works.

You mean whether the cap is shunted to the load and power source?
Because "in conjunction" means "in series with" right? At least,
that's how I've heard it mentioned before.

[Tim Wescott]

On Sat, 16 Feb 2013 10:13:55 -0500, Existential Angst wrote:

> What are the pro's/cons of each?
>
> One pro for caps is that they are cheaper! The AVR ditty for my unit
> would cost another near-$400.
> The pro for AVR is, presumably, much tighter voltage regulation with
> load.
>
> But mebbe AVR has its limits ito ruggedness?
>
> The voltage swing on my genset is 250 - 230 V, 0-50 A. Units with AVR
> claim 1-2% regulation.
>
> Should I spring for the AVR? If a major outtage occurs, I'll be running
> cnc equpment from it.

Do you have a link to a site that sells the AVR ditty? If it's
regulating the field current of the generator in response to the
generator voltage, and if all the genset does is rely on the motor's
governor for speed regulation, then it should give better regulation.

But I can only speak from a combination of a deep knowledge of control
systems theory, a reasonably deep knowledge of how generators work and
how Briggs and Stratton engines work, and a near total ignorance of how
people actually put these things together in practice.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

[Robert]

On Feb 17, 9:24 am, "trad...@optonline.net" <trad...@optonline.net>
wrote:

>
> It's not hard to find discussion of caps as voltage
> regulators. Here's an example, about a third of the
> way down in this thread:
>
> http://www.smokstak.com/forum/showthread.php?t=16338
>
> Seems like a pretty crappy thing to find though on a
> $3000 generator.

Thanks for the link. From that thread, I determined that the
keyphrase I needed to google was "alternator feedback
capacitor".... That gave me the link to a paper called
"Field Initiation Design Fundamentals for Pulsed Alternators"
which has an abstract giving a short explanation of how
the capacitor works. This was an IEEE paper.

It is simply a bootstrap giving feedback to the field of
an alternator....... Not a particularly good regulator, but
sufficient for non precise applications. I had never seen
this before, as I had only used electronic regulators to
the field windings of an alternator with a DC field and not pulsed
alternators.... Live and learn.....

Anyway, if the voltage regulation is critical , an
electronic regulator would work far better.

[Jim Wilkins]

"Robert" <jungl...@hotmail.com> wrote in message

news:11864198-e5a3-4016-b3dc->

> Anyway, if the voltage regulation is critical , an
> electronic regulator would work far better.

Would it be better to regulate the peak, average or RMS voltage if the
load draws non-sinusoidal current?

I became concerned with the peak after a poorly regulated generator
burned out the transient voltage suppressors in an outlet strip, in a
cloud of purple smoke.
jsw

[jon_banquer]

On Feb 17, 9:40 am, "Existential Angst" <fit...@optonline.net> wrote:
> "jon_banquer" <jonbanq...@yahoo.com> wrote in message

I'm hearing almost all air compressor pumps are made in either China
or India. That includes Ingersoll Rand. Thinking that Northern Tool
may not be the way to go. Found this. Like the price and the specs:

http://www.eatoncompressor.com/catalog/item/518643/1320611.htm

[jon_banquer]

http://wiki.answers.com/Q/Are_Ingersoll_Rand_compressors_made_in_the_USA

[Michael A. Terrell]

Maybe a third cousin, twice removed? :)

[Gunner]

A lot of folks replace the battery on English motorcycles with a big
cap for the same reasons

Gunner

The methodology of the left has always been:

1. Lie
2. Repeat the lie as many times as possible
3. Have as many people repeat the lie as often as possible
4. Eventually, the uninformed believe the lie
5. The lie will then be made into some form oflaw
6. Then everyone must conform to the lie

[The Daring Dufas]

We could always ask Nikola. ^_^

TDD

[Michael A. Terrell]

Nah, he's always so tesla...

[Existential Angst]

"Robert" <jungl...@hotmail.com> wrote in message

news:11864198-e5a3-4016...@h11g2000vbf.googlegroups.com...

So caps ARE regulators of sorts? Not just tuning/balancing?

I wonder, if/when I put on this AVR doodad, if the caps should be removed,
or left in place.
--
EA

[The Daring Dufas]

At least he alternates. ^_^

TDD

[Robert]

On Feb 17, 7:04 pm, "Jim Wilkins" <muratla...@gmail.com> wrote:
ulator would work far better.
>
> Would it be better to regulate the peak, average or RMS voltage if the
> load draws non-sinusoidal current?
>
> I became concerned with the peak after a poorly regulated generator
> burned out the transient voltage suppressors in an outlet strip, in a
> cloud of purple smoke.
> jsw

If the output is non-sinusoidal alternating current, it would
depend on the use. If equipment is being used that uses
the entire waveform, such as a heater, the RMS would be
the choice. For a motor, I'm not sure, but I'd go with RMS
unless better info is found. If the device is electronic, which
uses a peak detector to form a DC for a power supply, the
peak would be reasonable....
However, it would be necessary to look at the output
waveform to make a really informed choice. For instance,
if the output is a square wave the choice would be different
from a stepped sinusoid.
Note that rotating machinery will put out a sinusoid but
many generators today use a speed lower than 3600 rpm and
use an inverter to make the frequency controlled output
voltage, often a "stepped sinusoid", which has the RMS
of the sinusoid AND the peak level of the sinusoid, but
synthesized in steps.

Also, if the output is DC or pulsed DC, a capacitor
stabilizes the voltage by reducing the ripple, the same
function as the battery in an automobile. For this
appication a big ass capacitor in parallel with a resistor
can, in many cases, take the place of the battery. If a
load is always present, the resistor won't be needed. \
Such stabilizing loads are often used in stabilizing the
DC system in large RVs if a battery isn't used.


The requirements are different for an AC system.
That accounts for some of the different solutions posted
here.

[tra...@optonline.net]

On Feb 18, 4:01 am, "Existential Angst" <fit...@optonline.net> wrote:
> "Robert" <junglean...@hotmail.com> wrote in message

> EA- Hide quoted text -

>
> - Show quoted text -

Do you have the Meccalte spec sheet, manual etc for the actual
generator head? That would be my source for
information. Assuming of course that the offered voltage
regulator from the company you bought the assembly
from is using a M voltage regulator on an M generator....
I would think the cap does need to be removed as the
electronic voltage regulator is going to control the
winding field instead of relying on the cap.
generator?

[Jim Wilkins]

"Robert" <jungl...@hotmail.com> wrote in message

news:d3b6efea-6eb8-4139...@hq4g2000vbb.googlegroups.com...

> On Feb 17, 7:04 pm, "Jim Wilkins" <muratla...@gmail.com> wrote:
> ulator would work far better.
>>
>> Would it be better to regulate the peak, average or RMS voltage if
>> the

>> load draws non-sinusoidal current?...

>> jsw
>
> If the output is non-sinusoidal alternating current, it would
> depend on the use. If equipment is being used that uses
> the entire waveform, such as a heater, the RMS would be
> the choice. For a motor, I'm not sure, but I'd go with RMS
> unless better info is found. If the device is electronic, which
> uses a peak detector to form a DC for a power supply, the
> peak would be reasonable....

I asked because I have several small generators that regulate voltage
poorly, typically they have to be set around 140V at no load to
maintain 105-110V at full load. Unless I'm running one large
insensitive load like the washing machine I pass the power through a
metered 20A Variac indoors and change its setting as I add or remove
loads.

The APC SmartUps I found at a flea market recently looks like it would
handle the variations automatically without modifying the generator.
They are too expensive new and not common enough used to be a general
solution.

Unfortunately I don't know how much overvoltage things will stand
without frying them. My house spiked up to 180VAC once from a
powerline problem and the lights buzzed loudly. I knew there was an
intermittent fault and was monitoring it. It turned out to be a
corroded splice in the neutral in the drop from the street. I needed
good evidence to convince the power company to replace the meter box
and weatherhead.

[George]

On 2/18/2013 12:50 AM, jon_banquer wrote:

>
> I'm hearing almost all air compressor pumps are made in either China
> or India. That includes Ingersoll Rand. Thinking that Northern Tool
> may not be the way to go. Found this. Like the price and the specs:
>
> http://www.eatoncompressor.com/catalog/item/518643/1320611.htm
>

Its not so much where things are made (would like to see more things
made here but many demand cheap stuff) but just like making stuff here
it is the overall process.


For example I know a local company that decided to take the
manufacturing of one of their products major assemblies off shore. They
were introduced to suppliers that did known good work and you could
inspect their factory and they would work with you to meet your
standards etc. But "heybub mode" kicked in and they decided they would
go for even cheaper. So they ended up with dozens of cargo containers
filled with weldments that were dimensionally incorrect with no recourse.

[Robert]

On Feb 18, 7:44 am, "Jim Wilkins" <muratla...@gmail.com> wrote:
>
> The APC SmartUps I found at a flea market recently looks like it would
> handle the variations automatically without modifying the generator.
> They are too expensive new and not common enough used to be a general
> solution.
>
> Unfortunately I don't know how much overvoltage things will stand
> without frying them. My house spiked up to 180VAC once from a
> powerline problem and the lights buzzed loudly. I knew there was an
> intermittent fault and was monitoring it. It turned out to be a
> corroded splice in the neutral in the drop from the street. I needed
> good evidence to convince the power company to replace the meter box
> and weatherhead.

Sorry, Jim,
But your wide applications are getting way outside my area
of expertise...... I , personally, would use the variac like
you are doing, and set each application up as needed.
For a general purpose application to do everything for
every purpose, tho, I'd probably buy a big generator as
used in RVs, or "whole house", and make sure the
warranty is paid up..... I doubt that this opinion is of any
use to you, but that's the best I can offer.. Good luck...

PS.... As an afterthought, an interested reader might
consider your "neutral" problem, and check the tightness
of their neutrals in the meter box, as well as the ground
wire connection beside the meter box.... It ain't rocket
surgery..... The power company doesn't like people
going into the meter box to tighten up the terminals...
.... to easy to steal power...

[Scott Dorsey]

tra...@optonline.net <tra...@optonline.net> wrote:
>Find the parts diagram for the Honda engine. They typically
>rely on centrifugal force. If the engine starts to slow down, the
>drop in centrifugal force causes movement of linkage connected
>to the carb throttle.

The engine governor has nothing to do with the output voltage regulation,
really.

With a conventional AC generator, the speed of the engine governs the
output frequency. The generator HAS to run at constant speed, usually
1800 rpm, in order to get 60 Hz out of the generator. Change the engine
speed, you change the line frequency.

This is why conventional AC generators ALL have a device to regulate the
field coil voltage in order to get constant output voltage. Some of these
devices are better than others.

The inverter-style generators are different and what makes them such a
big advancement is that they allow you to run the engine at different
speeds for different loads by decoupling the engine speed and the final
output frequency.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Tim Wescott <t...@seemywebsite.please> wrote:
>
>Do you have a link to a site that sells the AVR ditty? If it's
>regulating the field current of the generator in response to the
>generator voltage, and if all the genset does is rely on the motor's
>governor for speed regulation, then it should give better regulation.

As far as I know, every non-inverter generator works this way. How else
would you get a stable output voltage with varying loads? It's not like
field coil regulation is terribly expensive; it's not a whole lot of current
in there.

>But I can only speak from a combination of a deep knowledge of control
>systems theory, a reasonably deep knowledge of how generators work and
>how Briggs and Stratton engines work, and a near total ignorance of how
>people actually put these things together in practice.

I never took power lab in school myself and I feel like I missed a big
opportunity.

[Jim Wilkins]

"Robert" <jungl...@hotmail.com> wrote in message

news:6820d266-c2c7-41e0-9bc1-

>
> PS.... As an afterthought, an interested reader might
> consider your "neutral" problem, and check the tightness
> of their neutrals in the meter box, as well as the ground
> wire connection beside the meter box.... It ain't rocket
> surgery..... The power company doesn't like people
> going into the meter box to tighten up the terminals...
> .... to easy to steal power...

The power company did try that first. The repairman and I cleaned the
meter box contact recesses with my collection of needle files and
nachinists scrapers. It seemed OK for a while, possibly because we had
pulled on the weatherhead connection, then I started to see the lights
flash and buzz at around 4:30PM. The line-to-line voltage held steady,
it was the neutral that was bouncing around.

I finally tracked it to a tree trunk shadow passing at that time over
the aluminum cable coming down the house, causing a brief drop and
then rise in its temperature.

[Jim Wilkins]

"Scott Dorsey" <klu...@panix.com> wrote in message
news:kftk95$8ep$1...@panix2.panix.com...

> Tim Wescott <t...@seemywebsite.please> wrote:
>>
>>Do you have a link to a site that sells the AVR ditty? If it's
>>regulating the field current of the generator in response to the
>>generator voltage, and if all the genset does is rely on the motor's
>>governor for speed regulation, then it should give better
>>regulation.
>
> As far as I know, every non-inverter generator works this way. How
> else
> would you get a stable output voltage with varying loads? It's not
> like
> field coil regulation is terribly expensive; it's not a whole lot of
> current
> in there.
>

How to regulate a permanent-magnet generator:
http://www.google.com/patents/US4766362
http://www.freepatentsonline.com/5625276.html (couldn't open)
http://www.google.com/patents?id=A1E9AAAAEBAJ&pg=PA2&source=gbs_selected_pages&cad=4#v=onepage&q&f=false
US 4,885,493
jsw

[Gunner]

On Mon, 18 Feb 2013 09:42:31 -0500, George <geo...@nospam.invalid>
wrote:

not long ago, I had to rebuild (3) small CNC lathes (OmniTurn) that
had been sent brand new..to Mexico for a very very very well known
medical company to manufacture stethescope hardware on. I do Not know
where they were operated..but the users were hamfisted brain dead
buffoons of the worst sort. The very very very well known company
finally got the hint and brought them back to the US, where I had to
do significant rebuilding of 2 yr old machines and place them in
American shops Its been almost 2 yrs and Ive been back to the new
location once just to do normal tune ups and a checkout and they are
running fine with no issues. and "M3" is happy with the machines
right where they are.

[tra...@optonline.net]

On Feb 18, 11:12 am, klu...@panix.com (Scott Dorsey) wrote:

> trad...@optonline.net <trad...@optonline.net> wrote:
> >Find the parts diagram for the Honda engine.  They typically
> >rely on centrifugal force.  If the engine starts to slow down, the
> >drop in centrifugal force causes movement of linkage connected
> >to the carb throttle.
>
> The engine governor has nothing to do with the output voltage regulation,
> really.

BS. And your reference for that claim, which flies in
the face of physics, would be?

>
> With a conventional AC generator, the speed of the engine governs the
> output frequency.  The generator HAS to run at constant speed, usually
> 1800 rpm, in order to get 60 Hz out of the generator.  Change the engine
> speed, you change the line frequency.

No shit sherlock and you also change the voltage.

>
> This is why conventional AC generators ALL have a device to regulate the
> field coil voltage in order to get constant output voltage.  Some of these
> devices are better than others.

That's true and why EA is asking about a cap versus
a ture electronic voltage regulator.

>
> The inverter-style generators are different and what makes them such a
> big advancement is that they allow you to run the engine at different
> speeds for different loads by decoupling the engine speed and the final
> output frequency.
> --scott
>
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."

I pointed that out several posts ago.

[Robert]

On Feb 18, 10:21 am, "Jim Wilkins" <muratla...@gmail.com> wrote:

> I finally tracked it to a tree trunk shadow passing at that time over
> the aluminum cable coming down the house, causing a brief drop and
> then rise in its temperature.

Wow ! Talk about a weird problem.... well, stuff happens !!!
Thanks for the post. I doubt that it would have
occurred to most readers and now we have
something to think about if it happens to us....
...... tighten the neutral connectiona the
weatherhead....

[Leon Fisk]

On Sun, 17 Feb 2013 11:23:27 -0500
"Existential Angst" <fit...@optonline.net> wrote:

<snip>

>McCaulte (sp?) makes the generator.

Website, instruction manuals here:

http://www.meccalte.com/index.php?s=52&page=0

The model number off your unit would be really helpful :)

Possibly the manual for your generator head:

http://www.meccalte.com/send_file.php?fileid=S20W%20manuale

"S20W Series:
6kVA to 8.5kVA 3000rpm 50Hz or
7.2kVA to 10.2kVA 3600rpm 60Hz"

or it might be this one:

http://www.meccalte.com/send_file.php?fileid=S20F%20manuale

"S20F Series:
8.5kVA to 12kVA 3000rpm 50Hz or
10.5kVA to 14.4kVA 3600rpm 60Hz"

Just guessing, using the output wattage you gave...

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

[jon_banquer]

Spoke with Eaton compressor at length today. Person I spoke with was
very knowledgeable and no bullshit. Their air compressor pumps have
been made in China for the last 12 years. They have dual suppliers in
China and the parts are interchangeable. They stock all the parts. I
like how the compressor pump I'm interested in runs at low RPM (850),
is 25 CFM (@90 PSI) and sells for $500. The also sell Lincoln electric
motors which are owned by Leeson. 7 1/2 HP Lincoln motor is $550. $65
for a pulley. Square D mag starter is $170. Pressure switch is $40.
Don't think I'm going to need multiple tanks. What do you see as the
benefit to multiple tanks if you have the right compressor to keep up
with your needs?

[Existential Angst]

"jon_banquer" <jonba...@yahoo.com> wrote in message
news:a5f60519-47c0-4c8c...@q11g2000pbt.googlegroups.com...

=============================================================

True, a good compressor does not require my staged tank strategy, but imo,
increasing tank capacity will extend the usable cfm rating of any
compressor, AND reduce it's cycling.

This is more important if you are going on the cheap, or have limited power,
or space. I got my 26 gal Husky as a floor model for $160 at HD, and just
added extra tanks as I stumbled across them -- could even be tall welding
tanks!
Dat 7.5 hp motor is going to dim the lights!
You can also save on the contactor by just using a simple relay, with the
coil wired into the pressure switch.
For me, space is at a premium, portability is really helpful.
And even a 26 gal Husky (vertical) is heav-eeeeee!! Holy shit.....
Also make sure it's easy to drain the tanks. I run a long hose from the
bottom, with a small ball valve at the end of the hose (1/4" white stuff,
like for a fridge's ice-maker), and just empty it into a bucket.

If you are going to mix'n'match, $550 for a motor seems like a lot, I would
go to a motor re-winding place, and see what they have on their shelves, for
cheap. They often have *hundreds* of spare motors to choose from, I'll bet
you could find sumpn suitable for under $100, mebbe way under.

Finagling "small" has its advantages. For example, if you have limited
power, and are running cnc, you don't want big-azz motors causing transient
voltage drops every time the pressor kicks in. So a smaller motor/pressor
is less electrical strain, and larger tank volume creates less cycling,
jolts to the electrical service.
Which also becomes even more important during outtages, if running off a
generator.
And also ito moving shit around...

If none of this is a factor, then you can go big and heavy and strong, but
if it is a factor, finagling small stuff helps -- a kind of "modularity".
--
EA

[Existential Angst]

"Leon Fisk" <lf...@no.spam.iserv.net> wrote in message
news:kfu2e5$e0a$1...@dont-email.me...

Yeah, I'm not sure either, I'll have poke around the generator -- oh,
actually, a booklet came with each component, I'll dig it up, post back.

Whatever it is, they'll be sending the AVR sized for that unit.
--
EA

[jon_banquer]

On Feb 19, 1:48 am, "Existential Angst" <fit...@optonline.net> wrote:
> "jon_banquer" <jonbanq...@yahoo.com> wrote in message

The advantage I see in running a well designed air compressor pump is
lots more CFM, less space, less noise and a longer lasting pump
because it can be run at much lower RPM. Doing something like
pressurized sandblasting eats up a lot of CFM.

One thing I'm now sure of:

When you buy a big name like Ingersoll Rand you aren't getting high
quality like you use to get 20 years ago. All you are buying now is
the name.

[Scott Dorsey]

Robert <jungl...@hotmail.com> wrote:
>
>Thanks for the link. From that thread, I determined that the
>keyphrase I needed to google was "alternator feedback
>capacitor".... That gave me the link to a paper called
>"Field Initiation Design Fundamentals for Pulsed Alternators"
>which has an abstract giving a short explanation of how
>the capacitor works. This was an IEEE paper.

I downloaded that paper, it's not actually using the capacitor as a
regulator at all. This is a trick for starting up a an air-core
alternator which doesn't have any residual magnetism to start current
in the armature when it's turned on, unlike a conventional steel-core
generator. I don't think any of this applies to the discussion at hand.

[Scott Dorsey]

Jim Wilkins <murat...@gmail.com> wrote:
>
>How to regulate a permanent-magnet generator:
>http://www.google.com/patents/US4766362
>http://www.freepatentsonline.com/5625276.html (couldn't open)
>http://www.google.com/patents?id=A1E9AAAAEBAJ&pg=PA2&source=gbs_selected_pages&cad=4#v=onepage&q&f=false
>US 4,885,493

This is very cool and quite ingenious but also not relevant to the
discussion at hand.

[Scott Dorsey]

tra...@optonline.net <tra...@optonline.net> wrote:

>On Feb 18, 11:12=A0am, klu...@panix.com (Scott Dorsey) wrote:
>> trad...@optonline.net <trad...@optonline.net> wrote:

>> With a conventional AC generator, the speed of the engine governs the

>> output frequency. =A0The generator HAS to run at constant speed, usually
>> 1800 rpm, in order to get 60 Hz out of the generator. =A0Change the engin=

>e
>> speed, you change the line frequency.
>
>No shit sherlock and you also change the voltage.

Possibly for one fraction of a cycle, but as soon as there is any change, the
field coil voltage will be increased to compensate for it. The mechanical
feedback loop that controls the engine speed is very very slow, because it
is limited by the inertia of the engine an the rotor. The electrical feedback
loop that controls the field coil voltage is pretty fast; it is limited
mostly by the inductance of the field coil.

>> This is why conventional AC generators ALL have a device to regulate the

>> field coil voltage in order to get constant output voltage. =A0Some of th=

>ese
>> devices are better than others.
>
>That's true and why EA is asking about a cap versus
>a ture electronic voltage regulator.

And what does he mean by "a cap?" As I said earlier, you have two choices
for voltage regulation: a feedback loop controlled by a mechanical buzzer, or
a feedback loop controlled by a solid state device. What is this mysterious
"capacitor regulation" that he has come up with? Nobody in this thread has
yet explained it, described it, or given an example of it.

[tra...@optonline.net]

On Feb 19, 1:54 pm, klu...@panix.com (Scott Dorsey) wrote:
> trad...@optonline.net <trad...@optonline.net> wrote:
> >On Feb 18, 11:12=A0am, klu...@panix.com (Scott Dorsey) wrote:
> >> trad...@optonline.net <trad...@optonline.net> wrote:
> >> With a conventional AC generator, the speed of the engine governs the
> >> output frequency. =A0The generator HAS to run at constant speed, usually
> >> 1800 rpm, in order to get 60 Hz out of the generator. =A0Change the engin=
> >e
> >> speed, you change the line frequency.
>
> >No shit sherlock and you also change the voltage.
>
> Possibly for one fraction of a cycle, but as soon as there is any change, the
> field coil voltage will be increased to compensate for it.

But what you stated was:

"The engine governor has nothing to do with the output voltage
regulation,
really. "

Which would mean to me that you could run a generator with a bad or
incorrectly adjusted governor running at 3400 RPPM, or 4000 RPM
and the only thing that would change is that the frequency would not
be 60hz, ie the voltage stays the same. That isn't true, because the
voltage is directly proportional to the speed too. I agree that
adjusting
the field is how the voltage is adjusted without changing the engine
speed.

The mechanical
> feedback loop that controls the engine speed is very very slow, because it
> is limited by the inertia of the engine an the rotor.  The electrical feedback
> loop that controls the field coil voltage is pretty fast; it is limited
> mostly by the inductance of the field coil.
>
> >> This is why conventional AC generators ALL have a device to regulate the
> >> field coil voltage in order to get constant output voltage. =A0Some of th=
> >ese
> >> devices are better than others.
>
> >That's true and why EA is asking about a cap versus
> >a ture electronic voltage regulator.
>
> And what does he mean by "a cap?"  As I said earlier, you have two choices
> for voltage regulation: a feedback loop controlled by a mechanical buzzer, or
> a feedback loop controlled by a solid state device.  What is this mysterious
> "capacitor regulation" that he has come up with?  Nobody in this thread has
> yet explained it, described it, or given an example of it.
> --scott
>
> --

I posted a link to a discussion on the subject previously.
Apparently capacitors are used as a cheap voltage regulator.
Also, just google and you'll find info.

[Scott Dorsey]

tra...@optonline.net <tra...@optonline.net> wrote:
>
>Which would mean to me that you could run a generator with a bad or
>incorrectly adjusted governor running at 3400 RPPM, or 4000 RPM
>and the only thing that would change is that the frequency would not
>be 60hz, ie the voltage stays the same. That isn't true, because the
>voltage is directly proportional to the speed too. I agree that
>adjusting
>the field is how the voltage is adjusted without changing the engine
>speed.

But you CAN run the generator at some other speed and the output voltage
will be the same. Try it! That's the purpose of the feedback control of
the field coil. The faster you run the thing, the more the regulator
will drop the voltage of the field coil. It completely decouples the operating
speed from the output voltage.

>I posted a link to a discussion on the subject previously.
>Apparently capacitors are used as a cheap voltage regulator.
>Also, just google and you'll find info.

This is just handwaving. What is actually going on? The capacitor can
be used to shift the phase of a signal, it can be used as part of a resonant
tank. What is the capacitor _doing_ in this magic circuit?

I have googled and I have seen nothing particularly useful, unfortunately.

[Transition Zone]

A cap is a given as a capacitor. You regulate voltage, raising it
means you lower its current. Increasing the current means you can run
something faster, like a fan, but you lower the voltage, so you are
regulating it in that sense. But the power is what always remains the
same (assuming reaction in the circuit isn't a factor).

[Larry W]

Anybody can make a spelling or grammar mistake or a simple typo in a
usenet post, but why would anyone do so intentionally?


--
There is always an easy solution to every human problem -- neat,
plausible, and wrong." (H L Mencken)

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org

[jon_banquer]

On Feb 19, 1:48 am, "Existential Angst" <fit...@optonline.net> wrote:
> "jon_banquer" <jonbanq...@yahoo.com> wrote in message

We both have a limited space problem.

Would something like this help you?

https://www.benchsolution.com/products/workbench/

[tra...@optonline.net]

On Feb 19, 4:40 pm, klu...@panix.com (Scott Dorsey) wrote:

> trad...@optonline.net <trad...@optonline.net> wrote:
>
> >Which would mean to me that you could run a generator with a bad or
> >incorrectly adjusted governor running at 3400 RPPM, or 4000 RPM
> >and the only thing that would change is that the frequency would not
> >be 60hz, ie the voltage stays the same.   That isn't true, because the
> >voltage is directly proportional to the speed too.  I agree that
> >adjusting
> >the field is how the voltage is adjusted without changing the engine
> >speed.
>
> But you CAN run the generator at some other speed and the output voltage
> will be the same.  Try it!  That's the purpose of the feedback control of
> the field coil.  The faster you run the thing, the more the regulator
> will drop the voltage of the field coil.  It completely decouples the operating
> speed from the output voltage.

Yes, IF the speed deviation is within the range of whatever
the voltage regulator is capable of maintaining.

>
> >I posted a link to a discussion on the subject previously.
> >Apparently capacitors are used as a cheap voltage regulator.
> >Also, just google and you'll find info.
>
> This is just handwaving.  What is actually going on?  The capacitor can
> be used to shift the phase of a signal, it can be used as part of a resonant
> tank.  What is the capacitor _doing_ in this magic circuit?
>
> I have googled and I have seen nothing particularly useful, unfortunately.
> --scott
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."

I agree that I haven't seen a technical description of how they
work. But there is enough info from some google searches
that shows that caps are used as voltage regulators in basic
generators.

[Existential Angst]

"jon_banquer" <jonba...@yahoo.com> wrote in message

news:e99b8e5c-e8ef-4cce...@m9g2000pby.googlegroups.com...

========================================================

Mebbe in a Leave-It-To-Beaver shop world..... lol
In MY world..... lessee, how to describe it....

The only way I can find a pencil in my shop is to buy a gross (or two) and
throw all 144 of them up in the air, throughout the shop. THEN mebbe I'll
be able to find a pencil somewhere.
Ditto flashlights, tape measures, calipers, you name it. I now have OVER 30
small led flashlights ( HD 8-packs, about $10, batts included) throughout
the house/shop -- and finding a flashlight is STILL hit and miss!!!

Funny, I built a drop-down welding table almost exactly like that, with
shelving on top, when I was still parking <gasp> CARS in the garage -- how
silly was DAT???
So I figgered Oh, Gee, I'll just drop down the table to park the cars....
Yeah, right.....
Dat drop-down welding table was dropped down exactly ONCE (to show the
wife), and was never ever deopped down again!! Cuz, well, dropping down
the table would mean..... <GASP> ..... CLEANING UP!!!! LOL
'tis the Nature of the Shop Beast.

Shit like dat is for Tool Time, or This ole House..... or shop teachers in
a well-funded school. Noble-ly ideal, but just not in the reality of The
Frazzled and The Cramped. Heh, and The Broke.

It DOES look beautiful, tho.
But it's sorta like exercise equipment/gadgets that store under yer bed.....
Guess what.... they then STAY under the bed. lol

I eventually took my drop down welding table out altogether and made it
REALLY useful:
I parked it on some milkcrates -- stacked three-high -- which is a li'l
tip for Iggy and his ridiculous 30" high welding tables. goodgawd.....

Which I really shouldn't knock......
cuz all those muthafuckas dumb enough to weld on his 30" welding table
will be calling Moi up for my apparatus/bars to stretch out/invert their
aching mis-aligned backs. Heh, I should send Ig a commission, eh?
Well, I will, but AFTER he sends the whole of RCM a commission check for the
*unending* (free) business advice he solicits ad nauseum.
--
EA

[Existential Angst]

"Larry W" <lwas...@sdf.lNoOnSePsAtMar.org> wrote in message
news:kg0v16$eml$1...@speranza.aioe.org...

> Anybody can make a spelling or grammar mistake or a simple typo in a
> usenet post, but why would anyone do so intentionally?

My phonetic rebellion..... no more o-u-g-h's for me -- enuf is enuf.

>
>
> --
> There is always an easy solution to every human problem -- neat,
> plausible, and wrong." (H L Mencken)

Einstein:
Shit should be made a simple as possible.... but no simpler.

Einstein:
If you think shit is simple, then you really don't understand shit.
--
EA

[tra...@optonline.net]

> same (assuming reaction in the circuit isn't a factor).- Hide quoted text -
>
> - Show quoted text -


Sigh.....

[Scott Dorsey]

tra...@optonline.net <tra...@optonline.net> wrote:
>
>I agree that I haven't seen a technical description of how they
>work. But there is enough info from some google searches
>that shows that caps are used as voltage regulators in basic
>generators.

Okay, here is the story! All of the details can be found in US Patent
4,269,368.

Looking at how this works, it's not a conventional brush-type alternator at
all, but an induction device almost like an induction motor in reverse. The
patent shows a single pole rotor with a diode across the winding, so the
rotor acts as a magnetic short in one direction and a magnetic open in the
other. This diode is really the key to the trick.

Now, the stator has two windings, physically 90 degrees apart. One winding
is the load winding, the other is the field coil itself, and the field coil
has a capacitor across it.

When the first pole of the rotor passes by, it induces a current in the
field winding that is proportional to the current passing through the
load coil (ie. proportional to the load being drawn). Then that pole
continues on and in the next 180 degrees of rotation induces a current
proportional in the load winding that is proportional to the current in
the field coil across the capacitor.

You can think of this not as an AC generator but as a device that creates
pulsed DC... the waveform is going to be very asymmetric. But, the amount
of voltage induced in the load coil should stay more or less sort of constant
with the current draw on it.

It really is a cheesy kind of trick, and I am not sure I'd want to use a
generator like this to run anything more sophisticated than an induction
motor, but there are plenty of folks out there who need to run induction
motors.

The capacitor isn't doing the regulation, it's just storing energy to keep
the field coil running.... the diode isn't doing the regulation, it's just
making sure the coils are both excited only in one direction.... it's the
design of the whole thing that is doing the regulation. Calling this
"capacitor-regulated" is incorrect but "capacitor-excited" is more like it.

I've never actually seen this before and the whole idea is just kind of
ingenious. The patent dates back to 1981 so this has clearly been in use
for a while. My guess is that in real life there are a bunch of poles on
the rotor with an individual diode for each pair, but I've never taken one
apart.

[Transition Zone]

On Feb 20, 7:58 am, "trad...@optonline.net" <trad...@optonline.net>

> Sigh.....

Oh, and with a split-phased capacitor, part of one phase can be used
to help start a motor before its brought back to normal running the
motor.

[Jim Wilkins]

"Scott Dorsey" <klu...@panix.com> wrote in message

news:kg59gr$edd$1...@panix2.panix.com...

> tra...@optonline.net <tra...@optonline.net> wrote:
>
> Looking at how this works, it's not a conventional brush-type
> alternator at
> all, but an induction device almost like an induction motor in
> reverse. The
> patent shows a single pole rotor with a diode across the winding, so
> the
> rotor acts as a magnetic short in one direction and a magnetic open
> in the
> other. This diode is really the key to the trick.
>

http://en.wikipedia.org/wiki/Magnetic_amplifier
"A relatively small DC current on the control winding is able to
control or switch large AC currents on the AC windings. This results
in current amplification."

[tra...@optonline.net]

> motor.- Hide quoted text -

>
> - Show quoted text -

Sigh.... None of which has any relevance to how a cap is used
to regulate voltage in a cheap generator.

[Transition Zone]

On Feb 21, 11:50 am, "trad...@optonline.net" <trad...@optonline.net>

> Sigh... None of which has any relevance to how a cap is used

> to regulate voltage in a cheap generator.

Why expect to regulate voltage if its that cheap?

[tra...@optonline.net]

> Why expect to regulate voltage if its that cheap?- Hide quoted text -

>
> - Show quoted text -

Another diversion into lala land. They apparently do it
because:


A - If you're not going to use an electonic voltage regulator which
costs a bit more, then having SOME voltage regulation on a generator
is better than none.

B - Customers want and expect some kind of voltage regulation
and the generator would probably be useless for most applications
without it.

C - A cap is cheap

[Tim Wescott]

On Mon, 18 Feb 2013 11:18:45 -0500, Scott Dorsey wrote:

> Tim Wescott <t...@seemywebsite.please> wrote:
>>
>>Do you have a link to a site that sells the AVR ditty? If it's
>>regulating the field current of the generator in response to the
>>generator voltage, and if all the genset does is rely on the motor's
>>governor for speed regulation, then it should give better regulation.
>
> As far as I know, every non-inverter generator works this way. How else
> would you get a stable output voltage with varying loads? It's not like
> field coil regulation is terribly expensive; it's not a whole lot of
> current in there.

With field coil regulation you should be able to keep the genset voltage
dead nuts on target, with deviations only when the load changes suddenly.

One wonders in what decade the technology stalled if they're allowing the
crappy regulation that EA quotes.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

[tra...@optonline.net]

I don't know, but the generator head is made by Meccalte,
an Italian manufacturer of real electric gear. You would think
on a generator that costs $2800 you'd get electronic voltage
regulation. But they apparently use a cap.

[Scott Dorsey]

Jim Wilkins <murat...@gmail.com> wrote:
>"Scott Dorsey" <klu...@panix.com> wrote in message

>> tra...@optonline.net <tra...@optonline.net> wrote:
>>
>> Looking at how this works, it's not a conventional brush-type
>> alternator at
>> all, but an induction device almost like an induction motor in
>> reverse. The
>> patent shows a single pole rotor with a diode across the winding, so
>> the
>> rotor acts as a magnetic short in one direction and a magnetic open
>> in the
>> other. This diode is really the key to the trick.
>>
>
>http://en.wikipedia.org/wiki/Magnetic_amplifier
>"A relatively small DC current on the control winding is able to
>control or switch large AC currents on the AC windings. This results
>in current amplification."

No, read the patent! It's not related to magnetic amplifiers at all;
nothing is operating in saturation. It is a very cool trick!

[anonymous]

replying to Pete S, anonymous wrote:
sumec fireman....the smallest


--
for full context, visit https://www.homeownershub.com/maintenance/genset-voltage-reg-capacitor-vs-avr-736855-.htm