Awl --

So I'm amassing a collection of perm. mag. DC motors for my various
(de)generative follies, but a friend said he took apart a gas powered
generator, and observed no magnets, with both stator and rotor being
wound -- suggesting that AC induction motors should provide juice, but mine
don't.

Was my friend wrong, or can wound rotors/stators yield juice, and if so,
under what conditions?

How are back-up generators generally wound, as well as prime generators,
such as coal, hydro, etc?

Will a typical 3 ph motor throw out juice, if driven by a pony motor?

Any primers on this stuff?
--
EA

Your friend was wrong. Motors need a magnetic field, whether permanent
magnet or electromagnet to produce voltage.

Three phase motors are typically induction types and produce the second
field of magnetism by induction from the wound fields.
Dynamic braking can use the collapsing field while they are turning for a
only short time to generate power but then the field is gone.

--------------------

"Existential Angst" wrote in message
...

Awl --

So I'm amassing a collection of perm. mag. DC motors for my various
(de)generative follies, but a friend said he took apart a gas powered
generator, and observed no magnets, with both stator and rotor being
wound -- suggesting that AC induction motors should provide juice, but mine
don't.

Was my friend wrong, or can wound rotors/stators yield juice, and if so,
under what conditions?

How are back-up generators generally wound, as well as prime generators,
such as coal, hydro, etc?

Will a typical 3 ph motor throw out juice, if driven by a pony motor?

Any primers on this stuff?
--
EA

"Existential Angst" wrote in message
...
Awl --

So I'm amassing a collection of perm. mag. DC motors for my various
(de)generative follies, but a friend said he took apart a gas powered
generator, and observed no magnets, with both stator and rotor being
wound -- suggesting that AC induction motors should provide juice, but
mine don't.

Was my friend wrong, or can wound rotors/stators yield juice, and if so,
under what conditions?

A motor that has both a wound rotor and a wound stator is not, as far as I
know, an AC induction motor. Induction motors have a rotor that's almost
always made up of very short conductors.

Old DC motors often had wound rotors and stators. Until powerful permanent
magnet came along, that's the way all but the smallest DC motors were made.
More than magnet strength, the issue was magnet permanence. All-wound DC
motors generally were of one of three types: series wound, parallel wound,
or series parallel combinations.

That's also the way many DC generators were made. I had an old WWII dynamo
set from a radio Jeep that was made that way. It supplied wire for many of
my ham radio coils back in the '60s.

Used as generators, they need a way to provide initial excitement to at
least one of the coils. There were various setups for this, including
relatively weak magnetized armatures, start batteries, and so on. Once they
were generating current they typically were designed to be self-exciting.

--
Ed Huntress


How are back-up generators generally wound, as well as prime generators,
such as coal, hydro, etc?

Will a typical 3 ph motor throw out juice, if driven by a pony motor?

Any primers on this stuff?
--
EA

Ed Huntress wrote:

(...)

Used as generators, they need a way to provide initial excitement to at
least one of the coils. There were various setups for this, including
relatively weak magnetized armatures, start batteries, and so on. Once they
were generating current they typically were designed to be self-exciting.

Via parallel capacitors?
http://www.qsl.net/ns8o/Induction_Generator.html


--Winston

"Winston" wrote in message
...
Ed Huntress wrote:

(...)

Used as generators, they need a way to provide initial excitement to at
least one of the coils. There were various setups for this, including
relatively weak magnetized armatures, start batteries, and so on. Once
they
were generating current they typically were designed to be self-exciting.

Via parallel capacitors?
http://www.qsl.net/ns8o/Induction_Generator.html


--Winston

That's a different situation, Winnie. Those are being used to provide
initial excitement to *induction* motors used as generators. That's a tricky
thing, and I didn't answer EA's question about three-phase induction motors
because it's something with which I have no experience.

But it may well be used to excite some all-wound DC generators, too. 'Don't
know. They were mostly before my time.

--
Ed Huntress

On Tue, 8 Mar 2011 23:31:31 -0500, "Josepi"
wrote:

Your friend was wrong. Motors need a magnetic field, whether permanent
magnet or electromagnet to produce voltage.

Three phase motors are typically induction types and produce the second
field of magnetism by induction from the wound fields.
Dynamic braking can use the collapsing field while they are turning for a
only short time to generate power but then the field is gone.

--------------------

"Existential Angst" wrote in message
...

Awl --

So I'm amassing a collection of perm. mag. DC motors for my various
(de)generative follies, but a friend said he took apart a gas powered
generator, and observed no magnets, with both stator and rotor being
wound -- suggesting that AC induction motors should provide juice, but mine
don't.

Was my friend wrong, or can wound rotors/stators yield juice, and if so,
under what conditions?

Many of the smallish generators (5KW to 50KW) in the Army had wound
rotors. They worked by bootstrapping: remnant magnetism in the iron
generated a small field current, which increased the generated
voltage, increasing the field current.... until the output voltage or
field current reached a threshold where some means of regulation
engaged. Occasionally a generator would fail to generate because
there wasn't enough remnant magnetism to get it going. The solution
was to "pole" the field by applying DC to it to re-magnetize it.


How are back-up generators generally wound, as well as prime generators,
such as coal, hydro, etc?

Will a typical 3 ph motor throw out juice, if driven by a pony motor?

In a way. It must be excited by the proper 3phase AC voltage, but if
the pony motor then spins the 3phase motor above synchronous speed,
the direction of current flow will be such as to deliver power to the
power line. An electric meter on that line would run backwards.

On Tue, 08 Mar 2011 23:24:34 -0500, Existential Angst wrote:

Awl --

So I'm amassing a collection of perm. mag. DC motors for my various
(de)generative follies, but a friend said he took apart a gas powered
generator, and observed no magnets, with both stator and rotor being
wound -- suggesting that AC induction motors should provide juice, but
mine don't.

Was my friend wrong, or can wound rotors/stators yield juice, and if so,
under what conditions?

Generally speaking, older, bigger rotating machines have field windings
that need DC excitation. You can regulate the voltage in a generator by
regulating the current in the field winding. It's exactly the same idea
as a car alternator.

How are back-up generators generally wound, as well as prime generators,
such as coal, hydro, etc?

Either with field windings, a motor designed to turn at exactly 1800 (or
3600) RPM to match line frequency, and a regulator connected to the field
windings. More recent ones have inverters, and probably permanent
generators AC generators whose output gets rectified then inverted.

As above, the bigger and older it is, the more likely it is to be a wound-
field synchronous AC machine.

Will a typical 3 ph motor throw out juice, if driven by a pony motor?

Well, yes, if the stars are aligned right. If you excite it with a
voltage, and turn it faster than its synchronous speed*, then it'll dump
current onto the line instead of sucking current from it. Older small-
time co-generation schemes did this, because maintaining synchronization
is _not_ trivial. Nowadays, it's mostly done with special inverters that
sense the voltage on the line and synchronize the current to the voltage.

Any primers on this stuff?

I dunno.

* Synchronous speed = 3600, 1800, 1200, etc., on down. So an induction
machine that has a design speed of 3540RPM has a synchronous speed of
3600RPM, and a slip of 1Hz. Turn it up to 3660RPM, and it'll absorb
something close to its rated power while putting almost that much power
onto the line along with some inductive loading.

--
http://www.wescottdesign.com

Ed Huntress wrote:
wrote in message
...
Ed Huntress wrote:

(...)

Used as generators, they need a way to provide initial excitement to at
least one of the coils. There were various setups for this, including
relatively weak magnetized armatures, start batteries, and so on. Once
they
were generating current they typically were designed to be self-exciting.

Via parallel capacitors?
http://www.qsl.net/ns8o/Induction_Generator.html


--Winston

That's a different situation, Winnie. Those are being used to provide
initial excitement to *induction* motors used as generators. That's a tricky
thing, and I didn't answer EA's question about three-phase induction motors
because it's something with which I have no experience.

But it may well be used to excite some all-wound DC generators, too. 'Don't
know. They were mostly before my time.

Three phase induction? This looks promising:
http://ronja.twibright.com/exciter/

Though the most I could ever accomplish was 70 W for half an hour
a day, so I don't expect to run my house from one of these.

(That parallel FET Q1 cannot be the best possible way
to regulate output power!) Yeesh.

--Winnie

"Winston" wrote in message
...
Ed Huntress wrote:
wrote in message
...
Ed Huntress wrote:

(...)

Used as generators, they need a way to provide initial excitement to at
least one of the coils. There were various setups for this, including
relatively weak magnetized armatures, start batteries, and so on. Once
they
were generating current they typically were designed to be
self-exciting.

Via parallel capacitors?
http://www.qsl.net/ns8o/Induction_Generator.html


--Winston

That's a different situation, Winnie. Those are being used to provide
initial excitement to *induction* motors used as generators. That's a
tricky
thing, and I didn't answer EA's question about three-phase induction
motors
because it's something with which I have no experience.

But it may well be used to excite some all-wound DC generators, too.
'Don't
know. They were mostly before my time.

Three phase induction? This looks promising:
http://ronja.twibright.com/exciter/

Though the most I could ever accomplish was 70 W for half an hour
a day, so I don't expect to run my house from one of these.

(That parallel FET Q1 cannot be the best possible way
to regulate output power!) Yeesh.


http://www.frenchriverland.com/Motor...th_UK_1994.pdf

--

PrecisionmachinisT wrote:

http://www.frenchriverland.com/Motor...th_UK_1994.pdf

Perused and copied.

Thanks PM!

--Winston

On Tue, 08 Mar 2011 21:48:08 -0800, Winston
wrote:

(That parallel FET Q1 cannot be the best possible way
to regulate output power!) Yeesh.

--Winnie

"Requires a massive heat sink". Yes, I'll bet it does! Lake Superior
comes to mind...

Not completely true.
Only reactive power (RVA) will flow back into the line and no "real" power
will flow into the line,except for losses due to heat in the "consumption"
direction.

The kW and kWh meter will not indicate backwards in this situation. The kVAR
and kVARh meters will indicate backward.
This is common with elevators that use their own motors for braking on
descent.

This is nicknamed "rotating capacitor" by some electric utilities and used
to correct power factor on lines and systems.

-----------------------
"Don Foreman" wrote in message
...
In a way. It must be excited by the proper 3phase AC voltage, but if
the pony motor then spins the 3phase motor above synchronous speed,
the direction of current flow will be such as to deliver power to the
power line. An electric meter on that line would run backwards.


Will a typical 3 ph motor throw out juice, if driven by a pony motor?

On 03/09/2011 04:26 PM, wrote:
A wound alternator needs some DC to start up, one reason you can't
push start a car with an alternator and a totally dead battery.

That is not strictly true. I drove a 72 AMC (with a Motorola Alternator)
for months without a battery in it. The alternator retains enough
magnetism to self excite enough to fire the coil. This was a carburated
straight 6. I lived and worked in a hilly area. If I killed it in
traffic, I was hosed.

A newer fuel injected vehicle requires enough current to run the fuel
pump and the computer in addition to the coil, so you be walking now.

BobH

On Mar 8, 9:24*pm, "Existential Angst" wrote:
Awl --

So I'm amassing a collection of perm. mag. DC motors for my various
(de)generative follies, but a friend said he took apart a gas powered
generator, and observed no magnets, with both stator and rotor being
wound -- suggesting that AC induction motors should provide juice, but mine
don't.

Was my friend wrong, or can wound rotors/stators yield juice, and if so,
under what conditions?

How are back-up generators generally wound, as well as prime generators,
such as coal, hydro, etc?

Will a typical 3 ph motor throw out juice, if driven by a pony motor?

Any primers on this stuff?
--
EA

A old-style non-PM DC generator usually relies on residual magnetism
in the pole pieces to start the cycle. One of the to-do items after
working on a VW generator was to connect the battery to the field
windings the correct way round in order to get startup polarity
correct. Just a quick zap to provide some residual magnetism.

A wound alternator needs some DC to start up, one reason you can't
push start a car with an alternator and a totally dead battery. When
I was a kid, my dad took me to visit one of the sites he was currently
working on, was a rural diesel power plant that had had a crankcase
explosion and was being rebuilt. Got the tour from the guys in
charge, had a huge V-16 engine attached to this dinky gray cylinder
about the size of a garbage can. I asked what that was, they said it
was the alternator. Had a tray of batteries sitting on a cart, were
the old squarish cells they used to use for doorbells, all connected
in series. That was the starting DC for the alternator when they were
going from blackout conditions, no juice anywhere.

An AC motor may work as a generator, but you'll have to provide some
method for providing and controlling the field current.

Stan

In basic motor and generator theory examples (many online) current passing
thru a conductor located within in a magnetic field/influence, or a
conductor moved thru a magnetic field are the basic principles.
Finding descriptions of how automotive alternators shouldn't be difficult,
and will likely explain a lot wrt generation.

Many generators utilize brushes, but induction motors can generate under the
proper conditions, as in Winston's referred example.

IIRC, the automotive generators of old cars utilized poles within the
stator/field windings, (and brushes).. the poles weren't permanent magnet
material, but they would hold in a magnet-like state after being properly
magnetized.. same/similar to Don's example.
If you can refer to an older automotive service manual (pre-1970s), you'll
likely find the procedure to stun? the pole pieces in those old generators.

A very weak/slow-motion motor example would be analog panel meters. In the
moving coil type meter movements, the coil (armature) is supported on low
friction pivot points (were jeweled bearings in days of old) within a
magnetic field.
When an appropriate small current flows, the meter needle deflects, and if
the moving coil is rotated manually (not a normal procedure), a small
current flows.
Many new analog meters are packaged with a shorting wire across the
terminals to dampen the needle movement during shipping.. an example of
braking of the generator effect.
Not all analog panel meters employ moving coils, though, and those which
aren't, don't effectively generate any current flow.

Over the years, I've seen a lot of DIY websites showing various generating
techniques from portable/emergency power to wind generation generators that
were made in home shops with powerful magnets (surplus suppliers) and
hand-wound coils on forms and later potted in epoxy or resin.

--
WB
..........


"Existential Angst" wrote in message
...
Awl --

So I'm amassing a collection of perm. mag. DC motors for my various
(de)generative follies, but a friend said he took apart a gas powered
generator, and observed no magnets, with both stator and rotor being
wound -- suggesting that AC induction motors should provide juice, but
mine don't.

Was my friend wrong, or can wound rotors/stators yield juice, and if so,
under what conditions?

How are back-up generators generally wound, as well as prime generators,
such as coal, hydro, etc?

Will a typical 3 ph motor throw out juice, if driven by a pony motor?

Any primers on this stuff?
--
EA

On 03/09/2011 05:47 AM, Josepi wrote:
(top posting fixed)
"Tim Wescott" wrote in message
...
Well, yes, if the stars are aligned right. If you excite it with a
voltage, and turn it faster than its synchronous speed*, then it'll dump
current onto the line instead of sucking current from it. Older small-
time co-generation schemes did this, because maintaining synchronization
is _not_ trivial. Nowadays, it's mostly done with special inverters that
sense the voltage on the line and synchronize the current to the voltage.


Will a typical 3 ph motor throw out juice, if driven by a pony motor?


Current? maybe but it will be 90 degrees out of phase with the
voltage.

It is often stated as putting reactive power back into the supply.

Nope, sorry, you're just plain wrong.

Using induction machines as generators is an established -- if slightly
obscure -- practice. Real mechanical power is transformed to real
electric power. There are some inductive VARs, but there's real VARs, too.

But don't argue with me. Argue with the world wide web:

http://en.wikipedia.org/wiki/Induction_generator
http://www.aerostarwind.com/induction_generator.html
http://www.daviddarling.info/encyclo...generator.html
http://www.electrodynamics.net/docum...er_gen2002.pdf

(and all the myriad other pages that come up when you search on
"induction generator).

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On Wed, 9 Mar 2011 08:42:18 -0500, "Josepi"
wrote:

Not completely true.
Only reactive power (RVA) will flow back into the line and no "real" power
will flow into the line,except for losses due to heat in the "consumption"
direction.

The kW and kWh meter will not indicate backwards in this situation. The kVAR
and kVARh meters will indicate backward.
This is common with elevators that use their own motors for braking on
descent.

This is nicknamed "rotating capacitor" by some electric utilities and used
to correct power factor on lines and systems.

Don't give up your day job, Josepi.

"Winston" wrote in message
...
Ed Huntress wrote:
wrote in message
...
Ed Huntress wrote:

(...)

Used as generators, they need a way to provide initial excitement to at
least one of the coils. There were various setups for this, including
relatively weak magnetized armatures, start batteries, and so on. Once
they
were generating current they typically were designed to be
self-exciting.

Via parallel capacitors?
http://www.qsl.net/ns8o/Induction_Generator.html


--Winston

That's a different situation, Winnie. Those are being used to provide
initial excitement to *induction* motors used as generators. That's a
tricky
thing, and I didn't answer EA's question about three-phase induction
motors
because it's something with which I have no experience.

But it may well be used to excite some all-wound DC generators, too.
'Don't
know. They were mostly before my time.

Three phase induction? This looks promising:
http://ronja.twibright.com/exciter/

Though the most I could ever accomplish was 70 W for half an hour
a day, so I don't expect to run my house from one of these.

That's actually not bad.
How did you determine that it was 70 W?
--
EA


(That parallel FET Q1 cannot be the best possible way
to regulate output power!) Yeesh.

--Winnie

Don Foreman wrote:

(...)

"Requires a massive heat sink". Yes, I'll bet it does! Lake Superior
comes to mind...

Heh!

--Winston

On 03/09/2011 07:42 AM, Josepi wrote:
Not completely true.
Only reactive power (RVA) will flow back into the line and no "real"
power will flow into the line,except for losses due to heat in the
"consumption" direction.

Nope, it is called an induction alternator, and definitely can generate
real power, as opposed to reactive. They are often used in small
hydropwer systems, and use the grid as backup and for regulation.
However, there ARE some people who have rigged these up as prime
alternators, and use various schemes to achieve regulation of both
voltage and frequency.


This is nicknamed "rotating capacitor" by some electric utilities and
used to correct power factor on lines and systems.

There used to be large motors used for phase angle correction in large
factories, etc. They had a wound field, and the excitation was
controlled by a phase angle meter, to correct the power factor drawn
from the utility grid. They got a big break on their electric bill for
using such a device. Often called a "rotary condenser".

Jon

On 03/08/2011 10:39 PM, Ed Huntress wrote:

A motor that has both a wound rotor and a wound stator is not, as far as I
know, an AC induction motor. Induction motors have a rotor that's almost
always made up of very short conductors.

There is a class of AC induction motor, now rarely seen, that DOES have
a wound rotor and a commutator much like on a DC motor. One difference
is they often have a "bracelet" in the commutator that flies out and
shorts all the segments together when the motor reaches a certain speed.

A variable resistor can be put in series with the brushes to regulate
torque when starting. We have an ancient merry-go-round here that has
such a motor, it takes about 3 minutes to come up to synchronous speed,
which would fry a standard induction motor. The operator slowly cranks
out the resistor as the motor speeds up.

These were also used on streetcars, and a variety of other things that
took a long time to start moving. Now, of course, a VFD would be used.

Jon

Existential Angst wrote:
wrote in message
...

(...)

Three phase induction? This looks promising:
http://ronja.twibright.com/exciter/

Though the most I could ever accomplish was 70 W for half an hour
a day, so I don't expect to run my house from one of these.

That's actually not bad.
How did you determine that it was 70 W?

At the time, I had an exercise bicycle that used a magnetic
'reluctance brake'. There was a knob next to the handlebar
yoke that I could twist to provide any amount of pedal
resistance. A meter next to it indicated the number of watts
I was converting. It probably wasn't terribly accurate but
it was good enough for a 'ballpark' figure and interesting
for a guy that is ~97% fat

Between 'warmup' and 'cool down', I could keep the needle
above 70 W for a half hour, consistently without endangering
my health.

I was very impressed when I learned that world - class
bicyclists can generate over 480 (Four Hundred Eighty)
watts continuously during a one hour time trial!

Dayum.

--Winston -- Now walking around, turning off room lights.

I will address only 3 of your questions:

Existential Angst wrote:

How are back-up generators generally wound, as well as prime generators,
such as coal, hydro, etc?
I have a couple of 6.5 KW Onan 120/240 volt 60hz generators. They both
have wound rotors and stators. One takes the power off the rotor via
slip rings and the other (newer) takes the power off the stator. In
this case the field,(the rotor) has dc supplied to it via slip rings.
Even though there is usually enough residual magnetism to get generation
going, both sets "flash" the field with some of the starting battery
juice to make sure the field current builds up quickly.

Will a typical 3 ph motor throw out juice, if driven by a pony motor?
Yes. I bought the Nigel Smith book mentioned in another post on this
thread. I focused on the setup called "C-2C", using a 3 phase motor to
produce single phase ac power. It does work. I am using a 5 hp 3 phase
electric motor which is being driven by a 12 hp Briggs gasoline engine
that is running at about 2200 rpm and belted to produce 60 hz at that
engine speed.

Any primers on this stuff?
Yes, The Nigel Smith book is the one to get. Also, type "induction
generator" into youtube and you won't see the light of day for about a week.

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

On a wound coil armature and a wound coil stator any residual magnetism can
induce a current into one of the coils and excite the other one. With motion
energy applied this can feed itself (self excite), as if the battery was
there, once in motion.

Without two sets of windings this doesn't happen.

---------------

"BobH" wrote in message ...
That is not strictly true. I drove a 72 AMC (with a Motorola Alternator)
for months without a battery in it. The alternator retains enough
magnetism to self excite enough to fire the coil. This was a carburated
straight 6. I lived and worked in a hilly area. If I killed it in
traffic, I was hosed.

A newer fuel injected vehicle requires enough current to run the fuel
pump and the computer in addition to the coil, so you be walking now.

BobH



On 03/09/2011 04:26 PM, wrote:
A wound alternator needs some DC to start up, one reason you can't
push start a car with an alternator and a totally dead battery.

"Winston" wrote in message
...
Existential Angst wrote:
wrote in message
...

(...)

Three phase induction? This looks promising:
http://ronja.twibright.com/exciter/

Though the most I could ever accomplish was 70 W for half an hour
a day, so I don't expect to run my house from one of these.

That's actually not bad.
How did you determine that it was 70 W?

At the time, I had an exercise bicycle that used a magnetic
'reluctance brake'. There was a knob next to the handlebar
yoke that I could twist to provide any amount of pedal
resistance. A meter next to it indicated the number of watts
I was converting. It probably wasn't terribly accurate but
it was good enough for a 'ballpark' figure and interesting
for a guy that is ~97% fat

Between 'warmup' and 'cool down', I could keep the needle
above 70 W for a half hour, consistently without endangering
my health.

I was very impressed when I learned that world - class
bicyclists can generate over 480 (Four Hundred Eighty)
watts continuously during a one hour time trial!

Dayum.

I wouldn't be too impressed, just yet.....

480 W for a continuous hour is proly some laboratory confabulation, from
devices that are not measuring watts, but calculating/inferring watts.
A lot of these bicycle watt meters are "watt calculators" from piezo sumpn
strain gauges/load cells, not from true generated electrical power. Dollars
to donuts, if you tested these guys on a real generator, you'd get far more
modest results.

Here's why:

If you calc backwards from a 480 watt mechanical output, you wind up with a
VO2 of 100.
Keep in mind that the elite of the elite possess VO2 *MAXes* of about 95,
and VO2max is a semi-instantaneous value, NOT a sustained value.
I'll have to check, but I think VO2max need only be sustained for a fraction
of a minute to qualify as VO2 max.

Sustained (aerobic) VO2s are usually *maybe* 80% of VO2max values. And that
last 20% is almost exponential in its perceived exertion, ie, quite
unsustainable.
Iow, a marathon runner may win a race at 80% of his VO2max (2+hours), but if
he "miscalculates", and runs at 90%, he may crap out after 1/2 hour -- or
sooner.

Marathon runners are toodling along at 18-20 cals/min, while your above
cyclist is calc'ing out at 34 cals/min -- which is unheard of, on a
sustained basis -- at least for 150 lb. guys. 300# -- mebbe.....

I'll post the calcs iffin inyone is innerested, basically just conversions.

Was *your* 70 W really 70 watts? Hard to say.
I can tell you that I can run for a solid hour (if you pay me), albeit not
at any earth-shaking pace, but at 180# and with hills, that is some
effort/expenditure.

The point being, I couldn't keep a 100 W lite bulb lit up for more than 3
minutes, a few days ago, on my cycle-generator.
Now, I think I'm getting better quickly, as I haven't cycled in literally 40
years, but still, even with substantial improvement, 1/2 hour at that output
is proly beyond my wherewithall -- both physical AND psychological!

100 W calcs out to a moderate but still substantial 10 cal/min, but in
reality is certainly more, depending on the efficiency of a PM DC motor.

Inyway, just some perspective on some of these hyooge wattage claims.
A little more perspective:
Some cyclists claim 2000 W peak outputs, which I might believe, over a
second or two.
Powerlifters have been measured at near-10,000 W instantaneous efforts, no
doubt over fractions of a second, possibly milliseconds. Staggering, when
you think about it.

But, what you can do for second is a *whole* lot different than what can be
done for 10 secs, 1 min, 5 min, 10 min, 1 hour.

And then, of course, you have the HSN/QVC pod peeple, effervescing: Oh,
Oh, OH, I just burntid 500 cals in 1/2 hour, and dint even knowed it!!!!!
Not hardly, sweetheart..... If you burntid 500 cals in 1/2 hour, you
likely woudn't be goin to work the next day.....
--
EA






--Winston -- Now walking around, turning off room lights.

"Existential Angst" wrote in message
...
"Winston" wrote in message
...
Existential Angst wrote:
wrote in message
...

(...)

Three phase induction? This looks promising:
http://ronja.twibright.com/exciter/

Though the most I could ever accomplish was 70 W for half an hour
a day, so I don't expect to run my house from one of these.

That's actually not bad.
How did you determine that it was 70 W?

At the time, I had an exercise bicycle that used a magnetic
'reluctance brake'. There was a knob next to the handlebar
yoke that I could twist to provide any amount of pedal
resistance. A meter next to it indicated the number of watts
I was converting. It probably wasn't terribly accurate but
it was good enough for a 'ballpark' figure and interesting
for a guy that is ~97% fat

Between 'warmup' and 'cool down', I could keep the needle
above 70 W for a half hour, consistently without endangering
my health.

I was very impressed when I learned that world - class
bicyclists can generate over 480 (Four Hundred Eighty)
watts continuously during a one hour time trial!

Dayum.

I wouldn't be too impressed, just yet.....

480 W for a continuous hour is proly some laboratory confabulation, from
devices that are not measuring watts, but calculating/inferring watts.
A lot of these bicycle watt meters are "watt calculators" from piezo sumpn
strain gauges/load cells, not from true generated electrical power.
Dollars to donuts, if you tested these guys on a real generator, you'd get
far more modest results.

Here's why:

If you calc backwards from a 480 watt mechanical output, you wind up with
a VO2 of 100.
Keep in mind that the elite of the elite possess VO2 *MAXes* of about 95,
and VO2max is a semi-instantaneous value, NOT a sustained value.
I'll have to check, but I think VO2max need only be sustained for a
fraction of a minute to qualify as VO2 max.

Sustained (aerobic) VO2s are usually *maybe* 80% of VO2max values. And
that last 20% is almost exponential in its perceived exertion, ie, quite
unsustainable.
Iow, a marathon runner may win a race at 80% of his VO2max (2+hours), but
if he "miscalculates", and runs at 90%, he may crap out after 1/2 hour --
or sooner.

Marathon runners are toodling along at 18-20 cals/min, while your above
cyclist is calc'ing out at 34 cals/min -- which is unheard of, on a
sustained basis -- at least for 150 lb. guys. 300# -- mebbe.....

I'll post the calcs iffin inyone is innerested, basically just
conversions.

Was *your* 70 W really 70 watts? Hard to say.
I can tell you that I can run for a solid hour (if you pay me), albeit not
at any earth-shaking pace, but at 180# and with hills, that is some
effort/expenditure.

The point being, I couldn't keep a 100 W lite bulb lit up for more than 3
minutes, a few days ago, on my cycle-generator.
Now, I think I'm getting better quickly, as I haven't cycled in literally
40 years, but still, even with substantial improvement, 1/2 hour at that
output is proly beyond my wherewithall -- both physical AND psychological!

100 W calcs out to a moderate but still substantial 10 cal/min, but in
reality is certainly more, depending on the efficiency of a PM DC motor.

Inyway, just some perspective on some of these hyooge wattage claims.
A little more perspective:
Some cyclists claim 2000 W peak outputs, which I might believe, over a
second or two.
Powerlifters have been measured at near-10,000 W instantaneous efforts, no
doubt over fractions of a second, possibly milliseconds. Staggering, when
you think about it.

But, what you can do for second is a *whole* lot different than what can
be done for 10 secs, 1 min, 5 min, 10 min, 1 hour.

And then, of course, you have the HSN/QVC pod peeple, effervescing: Oh,
Oh, OH, I just burntid 500 cals in 1/2 hour, and dint even knowed it!!!!!
Not hardly, sweetheart..... If you burntid 500 cals in 1/2 hour, you
likely woudn't be goin to work the next day.....
--
EA

FWIW, when the Gossamer Albratross crossed the English Channel, which took 2
hours and 49 minutes, the power required in still air was said to be 0.4
hp -- about 300 W, on average. That assumed still air. Normal disturbances
increase the horsepower required.

Here's a quote from a cometitive cyclist and engineer. It agrees with what I
was told when I competed in road sprints, back when tires were made of cast
iron g:

"Most fit adults can produce 100 watts (0.134 horsepower) of mechanical
power on a bicycle for a sustained period. A world-class competitive cyclist
can produce up to 500 watts (0.67 horsepower) over a sustained period of
time."

Of course, you'll get a lot less from a small generator. IIRC, automobile
alternators are something like 60% efficient, and there is the mechanical
loss involved in driving them. Permanent-magnet alternators in the same
size, however, are said to be up to 90% efficient. Don't ask me.

--
Ed Huntress

Existential Angst wrote:

(...)

Was *your* 70 W really 70 watts? Hard to say.

I don't really know for sure. That's just what the instrument
indicated.

--Winston

Ed Huntress wrote:
"Existential wrote in message
...
wrote in message
...

(...)

Between 'warmup' and 'cool down', I could keep the needle
above 70 W for a half hour, consistently without endangering
my health.

I was very impressed when I learned that world - class
bicyclists can generate over 480 (Four Hundred Eighty)
watts continuously during a one hour time trial!

Dayum.

I wouldn't be too impressed, just yet.....

(...)

--
EA

FWIW, when the Gossamer Albratross crossed the English Channel, which took 2
hours and 49 minutes, the power required in still air was said to be 0.4
hp -- about 300 W, on average. That assumed still air. Normal disturbances
increase the horsepower required.

Here's a quote from a cometitive cyclist and engineer. It agrees with what I
was told when I competed in road sprints, back when tires were made of cast
irong:

We would have killed for cast iron.
They made *us* knap our tires from granite.

"Most fit adults can produce 100 watts (0.134 horsepower) of mechanical
power on a bicycle for a sustained period.

That is believable considering that a physically compromised
middle - aged schlub managed 70 W for 30 minutes twice a week.

A world-class competitive cyclist
can produce up to 500 watts (0.67 horsepower) over a sustained period of
time."

Stunning!

Of course, you'll get a lot less from a small generator. IIRC, automobile
alternators are something like 60% efficient, and there is the mechanical
loss involved in driving them.

...And the often - ignored massive amount of power needed for the
field winding.

Permanent-magnet alternators in the same
size, however, are said to be up to 90% efficient. Don't ask me.

Thus their use in 'n'+1 alternative energy devices:
http://www.google.com/search?hl=en&source=hp&q="PM+alternator"+&aq=f&aqi =g1g-v9&aql=&oq=

--Winston

"Winston" wrote in message
...
Ed Huntress wrote:
"Existential wrote in message
...
wrote in message
...

(...)

Between 'warmup' and 'cool down', I could keep the needle
above 70 W for a half hour, consistently without endangering
my health.

I was very impressed when I learned that world - class
bicyclists can generate over 480 (Four Hundred Eighty)
watts continuously during a one hour time trial!

Dayum.

I wouldn't be too impressed, just yet.....

(...)

--
EA

FWIW, when the Gossamer Albratross crossed the English Channel, which
took 2
hours and 49 minutes, the power required in still air was said to be 0.4
hp -- about 300 W, on average. That assumed still air. Normal
disturbances
increase the horsepower required.

Here's a quote from a cometitive cyclist and engineer. It agrees with
what I
was told when I competed in road sprints, back when tires were made of
cast
irong:

We would have killed for cast iron.
They made *us* knap our tires from granite.

Oh, c'mon. Now you're exaggerating. It takes too long to knap tires from
granite. There probably are some RCM members who have tried...


"Most fit adults can produce 100 watts (0.134 horsepower) of mechanical
power on a bicycle for a sustained period.

That is believable considering that a physically compromised
middle - aged schlub managed 70 W for 30 minutes twice a week.

A world-class competitive cyclist
can produce up to 500 watts (0.67 horsepower) over a sustained period of
time."

Stunning!

Of course, you'll get a lot less from a small generator. IIRC, automobile
alternators are something like 60% efficient, and there is the mechanical
loss involved in driving them.

..And the often - ignored massive amount of power needed for the
field winding.

I think that the 60% includes the power lost by exciting the field. Again,
going from memory, I think that automobile alternators are reluctance-type.
They're flexible but not particularly efficient.


Permanent-magnet alternators in the same
size, however, are said to be up to 90% efficient. Don't ask me.

Thus their use in 'n'+1 alternative energy devices:
http://www.google.com/search?hl=en&source=hp&q="PM+alternator"+&aq=f&aqi =g1g-v9&aql=&oq=

--Winston

"Ed Huntress" wrote in message
...

"Existential Angst" wrote in message
...
"Winston" wrote in message
...
Existential Angst wrote:
wrote in message
...

(...)

Three phase induction? This looks promising:
http://ronja.twibright.com/exciter/

Though the most I could ever accomplish was 70 W for half an hour
a day, so I don't expect to run my house from one of these.

That's actually not bad.
How did you determine that it was 70 W?

At the time, I had an exercise bicycle that used a magnetic
'reluctance brake'. There was a knob next to the handlebar
yoke that I could twist to provide any amount of pedal
resistance. A meter next to it indicated the number of watts
I was converting. It probably wasn't terribly accurate but
it was good enough for a 'ballpark' figure and interesting
for a guy that is ~97% fat

Between 'warmup' and 'cool down', I could keep the needle
above 70 W for a half hour, consistently without endangering
my health.

I was very impressed when I learned that world - class
bicyclists can generate over 480 (Four Hundred Eighty)
watts continuously during a one hour time trial!

Dayum.

I wouldn't be too impressed, just yet.....

480 W for a continuous hour is proly some laboratory confabulation, from
devices that are not measuring watts, but calculating/inferring watts.
A lot of these bicycle watt meters are "watt calculators" from piezo
sumpn strain gauges/load cells, not from true generated electrical power.
Dollars to donuts, if you tested these guys on a real generator, you'd
get far more modest results.

Here's why:

If you calc backwards from a 480 watt mechanical output, you wind up with
a VO2 of 100.
Keep in mind that the elite of the elite possess VO2 *MAXes* of about 95,
and VO2max is a semi-instantaneous value, NOT a sustained value.
I'll have to check, but I think VO2max need only be sustained for a
fraction of a minute to qualify as VO2 max.

Sustained (aerobic) VO2s are usually *maybe* 80% of VO2max values. And
that last 20% is almost exponential in its perceived exertion, ie, quite
unsustainable.
Iow, a marathon runner may win a race at 80% of his VO2max (2+hours), but
if he "miscalculates", and runs at 90%, he may crap out after 1/2 hour --
or sooner.

Marathon runners are toodling along at 18-20 cals/min, while your above
cyclist is calc'ing out at 34 cals/min -- which is unheard of, on a
sustained basis -- at least for 150 lb. guys. 300# -- mebbe.....

I'll post the calcs iffin inyone is innerested, basically just
conversions.

Was *your* 70 W really 70 watts? Hard to say.
I can tell you that I can run for a solid hour (if you pay me), albeit
not at any earth-shaking pace, but at 180# and with hills, that is some
effort/expenditure.

The point being, I couldn't keep a 100 W lite bulb lit up for more than 3
minutes, a few days ago, on my cycle-generator.
Now, I think I'm getting better quickly, as I haven't cycled in literally
40 years, but still, even with substantial improvement, 1/2 hour at that
output is proly beyond my wherewithall -- both physical AND
psychological!

100 W calcs out to a moderate but still substantial 10 cal/min, but in
reality is certainly more, depending on the efficiency of a PM DC motor.

Inyway, just some perspective on some of these hyooge wattage claims.
A little more perspective:
Some cyclists claim 2000 W peak outputs, which I might believe, over a
second or two.
Powerlifters have been measured at near-10,000 W instantaneous efforts,
no doubt over fractions of a second, possibly milliseconds. Staggering,
when you think about it.

But, what you can do for second is a *whole* lot different than what can
be done for 10 secs, 1 min, 5 min, 10 min, 1 hour.

And then, of course, you have the HSN/QVC pod peeple, effervescing: Oh,
Oh, OH, I just burntid 500 cals in 1/2 hour, and dint even knowed it!!!!!
Not hardly, sweetheart..... If you burntid 500 cals in 1/2 hour, you
likely woudn't be goin to work the next day.....
--
EA

FWIW, when the Gossamer Albratross crossed the English Channel, which took
2 hours and 49 minutes, the power required in still air was said to be 0.4
hp -- about 300 W, on average. That assumed still air. Normal disturbances
increase the horsepower required.

Here's a quote from a cometitive cyclist and engineer. It agrees with what
I was told when I competed in road sprints, back when tires were made of
cast iron g:

"Most fit adults can produce 100 watts (0.134 horsepower) of mechanical
power on a bicycle for a sustained period.

I hope "a sustained period" = three minutes! LOL!!!!
Makes you wonder how one defines "most fit adults"....

Heh, you *could* make it foolproof/tautological by defining fit adults as
those who can generate 100 W for 1/2 continuous hours.... LOL!!!

A world-class competitive cyclist
can produce up to 500 watts (0.67 horsepower) over a sustained period of
time."

I'll believe dat **** when I see five 100 W bulbs at full brightness for a
solid hour.....

Previously, I managed 2:45. Just now I managed 3:30... that's
minutes/seconds... LOL!!!

Now, "manage" is really context sensitive... at what point does one
"quit"?
With no objective blood/lab values, that's really a dicey Q for true
reproducibility, so I use a kind arbitrary "pain threshhold": where I'm
whining for my mommy, but not yet screaming for her....

I suspect Thurs or Fri I'll be up to 5 minutes, and mebbe 10 minutes in
another week, but the point is, Goddamm, I fairly regularly run a hilly full
1/2 hour (2.5 miles or so), so if 100 TRUE watts is hard for me.....

Now, I estimated the driveline friction at about 12 W, and mebbe the PM
motor (perty old... how can I tell? cuz it's not made like ****....) is
80% efficient??
So ackshooly, that adds up to 137 W....
But proly other true bicycle generators would similar characteristics....
but not these "interpreted cycle watt-meters"....

So the comparison issue is still a begged issue.... Who really knows WTF is
up with internal losses, or even true wattage readings, eh? So how do we
really compare results, over the internet with diff setups?


Of course, you'll get a lot less from a small generator. IIRC, automobile
alternators are something like 60% efficient, and there is the mechanical
loss involved in driving them. Permanent-magnet alternators in the same
size, however, are said to be up to 90% efficient. Don't ask me.

Funny, high efficiency motors are sposedly 98% efficient.... 3 ph, no
doubt.
--
EA



--
Ed Huntress

I highly doubt you can tell if a 100W bulb is lit 100%. The human eye is not
that sensitive to relative lighting.

Talk about using actual power measurements...LOL

--------------
"Existential Angst" wrote in message
...

I wouldn't be too impressed, just yet.....

480 W for a continuous hour is proly some laboratory confabulation, from
devices that are not measuring watts, but calculating/inferring watts.
A lot of these bicycle watt meters are "watt calculators" from piezo sumpn
strain gauges/load cells, not from true generated electrical power. Dollars
to donuts, if you tested these guys on a real generator, you'd get far more
modest results.

Here's why:

If you calc backwards from a 480 watt mechanical output, you wind up with a
VO2 of 100.
Keep in mind that the elite of the elite possess VO2 *MAXes* of about 95,
and VO2max is a semi-instantaneous value, NOT a sustained value.
I'll have to check, but I think VO2max need only be sustained for a fraction
of a minute to qualify as VO2 max.

Sustained (aerobic) VO2s are usually *maybe* 80% of VO2max values. And that
last 20% is almost exponential in its perceived exertion, ie, quite
unsustainable.
Iow, a marathon runner may win a race at 80% of his VO2max (2+hours), but if
he "miscalculates", and runs at 90%, he may crap out after 1/2 hour -- or
sooner.

Marathon runners are toodling along at 18-20 cals/min, while your above
cyclist is calc'ing out at 34 cals/min -- which is unheard of, on a
sustained basis -- at least for 150 lb. guys. 300# -- mebbe.....

I'll post the calcs iffin inyone is innerested, basically just conversions.

Was *your* 70 W really 70 watts? Hard to say.
I can tell you that I can run for a solid hour (if you pay me), albeit not
at any earth-shaking pace, but at 180# and with hills, that is some
effort/expenditure.

The point being, I couldn't keep a 100 W lite bulb lit up for more than 3
minutes, a few days ago, on my cycle-generator.
Now, I think I'm getting better quickly, as I haven't cycled in literally 40
years, but still, even with substantial improvement, 1/2 hour at that output
is proly beyond my wherewithall -- both physical AND psychological!

100 W calcs out to a moderate but still substantial 10 cal/min, but in
reality is certainly more, depending on the efficiency of a PM DC motor.

Inyway, just some perspective on some of these hyooge wattage claims.
A little more perspective:
Some cyclists claim 2000 W peak outputs, which I might believe, over a
second or two.
Powerlifters have been measured at near-10,000 W instantaneous efforts, no
doubt over fractions of a second, possibly milliseconds. Staggering, when
you think about it.

But, what you can do for second is a *whole* lot different than what can be
done for 10 secs, 1 min, 5 min, 10 min, 1 hour.

And then, of course, you have the HSN/QVC pod peeple, effervescing: Oh,
Oh, OH, I just burntid 500 cals in 1/2 hour, and dint even knowed it!!!!!
Not hardly, sweetheart..... If you burntid 500 cals in 1/2 hour, you
likely woudn't be goin to work the next day.....
--
EA






--Winston -- Now walking around, turning off room lights.

Probably much more accurate then an estimate of a 100W bulb brightness.

----------------
"Winston" wrote in message ...
I don't really know for sure. That's just what the instrument
indicated.

---------------

Existential Angst wrote:
Was *your* 70 W really 70 watts? Hard to say.

Ed Huntress wrote:
wrote in message
...

(...)

We would have killed for cast iron.
They made *us* knap our tires from granite.

Oh, c'mon. Now you're exaggerating.

Busted. Curses!

It takes too long to knap tires from
granite. There probably are some RCM members who have tried...

Doubtlessly.

I think that automobile alternators are reluctance-type.
They're flexible but not particularly efficient.

I see where Bosch are touting their new 70% efficient 'smart'
alternator that allows digital control so that field
current can be turned off during acceleration and
cranked up during braking, boosting engine efficiency
by as much as 3%. Smart Indeed!

http://csr.bosch.com/content/languag...ENU_XHTML.aspx


--Winston

"Josepi" wrote in message
...
Probably much more accurate then an estimate of a 100W bulb brightness.

First, not an informed statement, as most fitness mfr's don't really care
what a watt even is, never mind actually making accurate calibrations
against a standard.

Second, there is no estimating of bulb brightness if you've got a voltmeter
in front of you, and you are maintaining 120 V. This then becomes as
accurate as anything, short of accurate/expensive regulators, solidstate
integrators, etc.
--
EA



----------------
"Winston" wrote in message ... I don't
really know for sure. That's just what the instrument
indicated.

---------------

Existential Angst wrote:
Was *your* 70 W really 70 watts? Hard to say.

"Winston" wrote in message
...
Ed Huntress wrote:
wrote in message
...

(...)

We would have killed for cast iron.
They made *us* knap our tires from granite.

Oh, c'mon. Now you're exaggerating.

Busted. Curses!

It takes too long to knap tires from
granite. There probably are some RCM members who have tried...

Doubtlessly.

I think that automobile alternators are reluctance-type.
They're flexible but not particularly efficient.

I see where Bosch are touting their new 70% efficient 'smart'
alternator that allows digital control so that field
current can be turned off during acceleration and
cranked up during braking, boosting engine efficiency
by as much as 3%. Smart Indeed!

http://csr.bosch.com/content/languag...ENU_XHTML.aspx


--Winston

These innovations are great to think about. Then it comes time to analyze
something gone wrong...

Speaking of which, my wife's Sonata died today -- the battery died because
her passenger left the door ajar at lunchtime -- and I was freaked when I
went over to school to jump start it. The intrusion alarm was feebly wailing
a plaintive cry, like a baby animal that was being torn apart by a raptor or
something, and I couldn't get it to stop. There was just enough juice left
in the battery to give out that feeble squeak, but not enough to react to
the remote. When I connected the jumper cables it went into full blast --
with my head under the hood and about 18 inches from the alarm. Jesus. I
didn't know I could still jump like that.

I want something I can fix with a screwdriver and a box of tools I could put
under my arm. A Lotus 6 or 7 might do it. No doors, even.

--
Ed Huntress

"Josepi" wrote in message
...
I highly doubt you can tell if a 100W bulb is lit 100%. The human eye is
not that sensitive to relative lighting.

Talk about using actual power measurements...LOL

At first, I didn't understand why others here call you an asshole....

Oh, and btw, prior to the digital age, laboratory pyrometers were exactly
based on relative brightness, which could be assessed with some precision.

If you wanted to be real anal (speaking of assholes), you could have a bulb
powered from a wall outlet, and then power the bike-driven bulb to
comparative brightness, quite accurately.

But, as I stated in my other reply to you, a much better solution is to
simply monitor a voltmeter while powering the bulb.

Are you still LOLing???
--
EA



--------------
"Existential Angst" wrote in message
...

I wouldn't be too impressed, just yet.....

480 W for a continuous hour is proly some laboratory confabulation, from
devices that are not measuring watts, but calculating/inferring watts.
A lot of these bicycle watt meters are "watt calculators" from piezo sumpn
strain gauges/load cells, not from true generated electrical power.
Dollars
to donuts, if you tested these guys on a real generator, you'd get far
more
modest results.

Here's why:

If you calc backwards from a 480 watt mechanical output, you wind up with
a
VO2 of 100.
Keep in mind that the elite of the elite possess VO2 *MAXes* of about 95,
and VO2max is a semi-instantaneous value, NOT a sustained value.
I'll have to check, but I think VO2max need only be sustained for a
fraction
of a minute to qualify as VO2 max.

Sustained (aerobic) VO2s are usually *maybe* 80% of VO2max values. And
that
last 20% is almost exponential in its perceived exertion, ie, quite
unsustainable.
Iow, a marathon runner may win a race at 80% of his VO2max (2+hours), but
if
he "miscalculates", and runs at 90%, he may crap out after 1/2 hour -- or
sooner.

Marathon runners are toodling along at 18-20 cals/min, while your above
cyclist is calc'ing out at 34 cals/min -- which is unheard of, on a
sustained basis -- at least for 150 lb. guys. 300# -- mebbe.....

I'll post the calcs iffin inyone is innerested, basically just
conversions.

Was *your* 70 W really 70 watts? Hard to say.
I can tell you that I can run for a solid hour (if you pay me), albeit not
at any earth-shaking pace, but at 180# and with hills, that is some
effort/expenditure.

The point being, I couldn't keep a 100 W lite bulb lit up for more than 3
minutes, a few days ago, on my cycle-generator.
Now, I think I'm getting better quickly, as I haven't cycled in literally
40
years, but still, even with substantial improvement, 1/2 hour at that
output
is proly beyond my wherewithall -- both physical AND psychological!

100 W calcs out to a moderate but still substantial 10 cal/min, but in
reality is certainly more, depending on the efficiency of a PM DC motor.

Inyway, just some perspective on some of these hyooge wattage claims.
A little more perspective:
Some cyclists claim 2000 W peak outputs, which I might believe, over a
second or two.
Powerlifters have been measured at near-10,000 W instantaneous efforts, no
doubt over fractions of a second, possibly milliseconds. Staggering, when
you think about it.

But, what you can do for second is a *whole* lot different than what can
be
done for 10 secs, 1 min, 5 min, 10 min, 1 hour.

And then, of course, you have the HSN/QVC pod peeple, effervescing: Oh,
Oh, OH, I just burntid 500 cals in 1/2 hour, and dint even knowed it!!!!!
Not hardly, sweetheart..... If you burntid 500 cals in 1/2 hour, you
likely woudn't be goin to work the next day.....
--
EA






--Winston -- Now walking around, turning off room lights.

"Josepi" wrote in message
...
(moronic posting format fixed)

I would love to see an example of this where you turn asynchronous motor
at 3660 poles per second on a 60Hz line and it puts ***real*** power back
into the line and the O/C protection stays intact. That is a completely
moronic statement in itself.


Not sure about the 3660 poles per second part but pretty sure just about
every windmill that is placed onto the grid does exactly this.

--

"spaco" wrote in message
.. .
I will address only 3 of your questions:

Existential Angst wrote:

How are back-up generators generally wound, as well as prime generators,
such as coal, hydro, etc?
I have a couple of 6.5 KW Onan 120/240 volt 60hz generators. They both
have wound rotors and stators. One takes the power off the rotor via slip
rings and the other (newer) takes the power off the stator. In this case
the field,(the rotor) has dc supplied to it via slip rings. Even though
there is usually enough residual magnetism to get generation going, both
sets "flash" the field with some of the starting battery juice to make
sure the field current builds up quickly.

Will a typical 3 ph motor throw out juice, if driven by a pony motor?
Yes. I bought the Nigel Smith book mentioned in another post on this
thread. I focused on the setup called "C-2C", using a 3 phase motor to
produce single phase ac power. It does work. I am using a 5 hp 3 phase
electric motor which is being driven by a 12 hp Briggs gasoline engine
that is running at about 2200 rpm and belted to produce 60 hz at that
engine speed.

Any primers on this stuff?
Yes, The Nigel Smith book is the one to get. Also, type "induction
generator" into youtube and you won't see the light of day for about a
week.


FWIW,

I have had the Nigel Smith book for nearly a decade now-actually bought the
thing--if there is a prolonged power outage here what I do is I run a 50 hp
3ph motor as a single phase induction generator off from my 23 hp kubota
tractor PTO--which easily powers the entire house including starting a 5 ton
heat pump compressor..

C2C connection gives you single phase off of a 3 phase motor, rpm ( 60 hz )
is via throttle governor and isnt particularily critical, 20% is probably
okay but if in doubt use a ole telechron clock, and compare with a quartz
unit..they bothe should read within a few seconds after a minute's time on
line...if not, then adjust your throttle to suit.
--

Ed Huntress wrote:

(...)

These innovations are great to think about. Then it comes time to analyze
something gone wrong...

One More Thing To Break.

Speaking of which, my wife's Sonata died today -- the battery died because
her passenger left the door ajar at lunchtime -- and I was freaked when I
went over to school to jump start it. The intrusion alarm was feebly wailing
a plaintive cry, like a baby animal that was being torn apart by a raptor or
something, and I couldn't get it to stop. There was just enough juice left
in the battery to give out that feeble squeak, but not enough to react to
the remote. When I connected the jumper cables it went into full blast --
with my head under the hood and about 18 inches from the alarm. Jesus. I
didn't know I could still jump like that.

Queue sympathetic headache. Ouch!

I want something I can fix with a screwdriver and a box of tools I could put
under my arm. A Lotus 6 or 7 might do it. No doors, even.

I've owned 'simple' cars.

I *will not* go back to carburetors, for I have *seen* the glory
of fuel injection on a cold and dreary morning!

I *will not* return to breaker points for I have known the
power of the Fat White Electronic Ignition Spark!

I *will not* slide back to the days of the bias ply tire
for I have sat in awe over the Indestructible Radial Ply!

Can I get an Amen, brothers and sisters.

--Winston -- Happy Herbert Akroyd Stuart Day to all
and to all a good night.

On Wed, 09 Mar 2011 15:13:15 -0600, Jon Elson
wrote:


There used to be large motors used for phase angle correction in large
factories, etc. They had a wound field, and the excitation was
controlled by a phase angle meter, to correct the power factor drawn
from the utility grid. They got a big break on their electric bill for
using such a device. Often called a "rotary condenser".

Those are over-excited synchronous motors.