Inpedance Protection of Ceiling Fan Motor

[Doug Goncz]

My ceiling fan motor, surpluscenter.com #10-1134, is impedance protected. I am
told this is so it will not overheat in a stall. I don't intend to stall it. I
am trying to use it as a pedal powered 110 VAC 60 Hz generator:

ftp://users.aol.com/DGoncz/

ftp://users.aol.com/DGoncz/Bicycle/ACMotorGenerator/

What is impedance protection, can it be removed, and is it the reason my
generator isn't working?

I have various capacitors available to wire across the leads, but they do not
seem to work. I do not have a working capacitance meter. I have five 30
microfarad capacitors rated 330 WVAC each. They are run caps. They are not
identical, but are similar.

I have attempted to pole the rotor with DC on the main lead set ( the motor has
four leads and uses a phase shift capacitor for reversible rotation ). It never
seemed to work. I have a bit of magnetic test strip available around here
somewhere. I suspected that when I connected the field coil to DC, and then
disconnected it, a resonance produced degaussing.

I intend to load the battery charger with 6 x 85,000 microfarads at 15 WVDC and
an inrush current limiter, to slowly apply full battery charging voltage to the
field coil. That will take a bit of time to set up, but on uplugging or
disconnecting the charger, the caps should produce a slowly decaying DC that
will not degauss the rotor.

What is impedance protection, etc?


Yours,
Doug Goncz ( ftp://users.aol.com/DGoncz/incoming )
Student member SAE for one year.
I love: Dona, Jeff, Kim, Mom, Neelix, Tasha, and Teri, alphabetically.
I drive: A double-step Thunderbolt with 657% range.

 

[Pooh Bear]

My ceiling fan motor, surpluscenter.com #10-1134, is impedance protected. I am
told this is so it will not overheat in a stall.
Correct.

I don't intend to stall it. I
am trying to use it as a pedal powered 110 VAC 60 Hz generator:

Bad choice.

What is impedance protection,

It means that the motor windings have sufficient inductance ( and hence impedance
@ line frequency ) to limit the current ( and hence the power dissipated ) to a
safe level under all circumstances that won't burn out the motor.

can it be removed,
No.

and is it the reason my generator isn't working?

Probably not. If it's the type of motor I expect it is - it is unsuitable for use
as a generator. Generators requires permanent magnets or coils that perform a
similar task when provided with an external current source.


Graham

 

[Doug Goncz]

From: Pooh Bear [email protected]

Message-ID: <[email protected]>

Doug Goncz wrote:

Probably not. If it's the type of motor I expect it is - it is unsuitable for
use
as a generator.

It _is_ an induction motor, inducing currents into the rotor "winding" cast
between laminations of steel. This type of motor is said to be suitable for use
as a generator when a suitable capacitance is provided across the output leads.

I take my opinion from "Secrets..." (of alternators and generators) from
Lindsay Publications, no longer available, and

http://www.qsl.net/ns8o/Induction_Generator.html

What is known is that induction motors operated below synchronous speed slip
and transform applied electrical power into mechanical power and induction
motors operated above synchronous speed slip and transform applied mechanical
power into electrical power.

What is claimed is that by attaching a capacitance to the motor and using
residual magnetism in the rotor, such a motor will operate as a generator _if
no load is present at start_ to damp the tiny excitation. I have only operated
my ceiling fan in generator mode with a DMM as a load and with various
connections of leads and capacitance. I have read up to 5 VAC output, nowhere
near 110 VAC.

Poling the rotor with DC to the field coil induces residual magnetism in the
rotor. Often, ambient residual magnetism is sufficient to self-start an
induction motor this way. Or at least, that's the claim in the pamphlet I read
and the web page I give here.

Generators requires permanent magnets or coils that perform a
similar task when provided with an external current source.

Yes, they do. But induction motor/generators are extremely reliable. No brushes
to wear out, no difficult assembly, no magnets to attract environmental
magnetic dust (meteoritic dust, iron filings, scrap metal, road debris).

Reliability is key here. Not efficiency. The design load is only 8 W and goes
off line automatically at 80 VAC.


Yours,
Doug Goncz ( ftp://users.aol.com/DGoncz/incoming )
Student member SAE for one year.
I love: Dona, Jeff, Kim, Mom, Neelix, Tasha, and Teri, alphabetically.
I drive: A double-step Thunderbolt with 657% range.

 

[Joerg]

Hi Doug,

If you only need 8W then a good bicycle generator plus inverter might
do. Or a good automotive generator. These actually live a long and
healthy life in such apps since they wouldn't be exposed to the huge
sideways pull of a belt. Even with that belt they often last a car's
lifetime, thousands of hours. I have talked to a guy who had a few of
these in a river-based generator and they run day and night, since the
early 90's.

Regards, Joerg

 

[Doug Goncz]

Dear Joerg,

From: Joerg [email protected]

If you only need 8W then a good bicycle generator plus inverter might
do.

Yes, I know that. But I want to be able to put the mettle to the pedal. That
is, I want to be able pull over while riding, extend the ESGE dual leg
kickstand, which is braced to take the load of my weight, charge the
ultracapacitors by pedaling at a heart rate of around 136, then fold the
kickstand and continue.

Oh. I didn't mention the ultracapacitors in this thread, did I?

I have sixteen Maxwell Technologies PC 2500, 2700 F, 2.5 WVDC ultracapacitors
rated 0.001 ohm series reistance. They can deliver 625 amps into a short.

I plan to use six on the bike and have received three double boards from
ExpressPCB.com. Each will hold a PB DPDT relay to put the caps in series or
paralle, and an (a) LED to indicate state of charge. I have eight relays and
six LEDs.

I just haven't soldered them up yet.

Google MOEPED for more. I already have a DC generator rated 30 VDC drive, 12 A
stall as a motor. I have generated 50 W easily with it. In fact, the voltage on
the caps rose so quickly I had to take it off line. Stopping wasn't an option,
I was on a hill. We're talking big mobile energy here.

Let's get back OT.

These actually live a long and
healthy life in such apps since they wouldn't be exposed to the huge
sideways pull of a belt.

I know. I want to be able to power an abandonded house. And the vehicle has to
be repaired in any bike shop in the world, or with standard parts like the
ceiling fan motor, which has 17 mm bore single row sheilded ball bearings that
can last thousands of hours, and are available easily. Just run with what I
wrote, OK, everybody?

I have talked to a guy who had a few of
these in a river-based generator and they run day and night, since the
early 90's.

Induction motors are even more reliable, and this is a military application. I
intend to submit an unsolicited proposal to the US Army's Dual-Use Technology
program.

There isn't any running water on a bike to power the proposed paddlewheels.

What is impedance protection, please, how does it work, and is it the factor
that prevent this generator from working?

Or is it not? Is there something else I need to do to get this generator
online?

ftp://users.aol.com/DGoncz/Bicycle/ACMotorGenerator

See it for yourself.

It's not an electrically propelled bicycle. It's a mobile power station.

The motor running in the AVI files is just being used to tune the shifters and
derailers by moving the pedals at a constant, reasonable rate while adjustments
are made. That's a secondary benefit available wherever a plug is available.


Yours,
Doug Goncz ( ftp://users.aol.com/DGoncz/incoming )
Student member SAE for one year.
I love: Dona, Jeff, Kim, Mom, Neelix, Tasha, and Teri, alphabetically.
I drive: A double-step Thunderbolt with 657% range.

 

[Tim Wescott]

Dear Joerg,

You wrote:




Yes, I know that. But I want to be able to put the mettle to the pedal. That
is, I want to be able pull over while riding, extend the ESGE dual leg
kickstand, which is braced to take the load of my weight, charge the
ultracapacitors by pedaling at a heart rate of around 136, then fold the
kickstand and continue.

Oh. I didn't mention the ultracapacitors in this thread, did I?

I have sixteen Maxwell Technologies PC 2500, 2700 F, 2.5 WVDC ultracapacitors
rated 0.001 ohm series reistance. They can deliver 625 amps into a short.

I plan to use six on the bike and have received three double boards from
ExpressPCB.com. Each will hold a PB DPDT relay to put the caps in series or
paralle, and an (a) LED to indicate state of charge. I have eight relays and
six LEDs.

I just haven't soldered them up yet.

Google MOEPED for more. I already have a DC generator rated 30 VDC drive, 12 A
stall as a motor. I have generated 50 W easily with it. In fact, the voltage on
the caps rose so quickly I had to take it off line. Stopping wasn't an option,
I was on a hill. We're talking big mobile energy here.

Let's get back OT.




I know. I want to be able to power an abandonded house. And the vehicle has to
be repaired in any bike shop in the world, or with standard parts like the
ceiling fan motor, which has 17 mm bore single row sheilded ball bearings that
can last thousands of hours, and are available easily. Just run with what I
wrote, OK, everybody?

Lessee. 17mm bore single row shielded ball bearings, or an alternator
out of the nearest parked car. Hmm.

Y'know, I bet the alternator will be easier to find.

Induction motors are even more reliable, and this is a military application. I
intend to submit an unsolicited proposal to the US Army's Dual-Use Technology
program.

For what? Bicycle shock troops?

There isn't any running water on a bike to power the proposed paddlewheels.

His point was about reliability. Once you've reached sufficent
reliability, more is just waste.

What is impedance protection, please, how does it work, and is it the factor
that prevent this generator from working?

In order: we told you about one post in on this thread, we told you
about one post in on this thread, and no.

Or is it not? Is there something else I need to do to get this generator
online?

Yes, externally excite it with 60Hz, 120VAC. We told you that, too, in
your last thread. Once you get your inverter going you'll have enough
components that the MTBF of your assembly will be _much_ lower than the
alternator out of the nearest parked car.

ftp://users.aol.com/DGoncz/Bicycle/ACMotorGenerator

See it for yourself.

It's not an electrically propelled bicycle. It's a mobile power station.

Somehow I think that the DOD is going to view gasoline for a motor as
being less expensive than C-rations for a 20-year-old. From a
watts/dollar standpoint it doesn't strike me as a winner.

 

[Pooh Bear]

It _is_ an induction motor, inducing currents into the rotor "winding" cast
between laminations of steel. This type of motor is said to be suitable for use
as a generator when a suitable capacitance is provided across the output leads.

I take my opinion from "Secrets..." (of alternators and generators) from
Lindsay Publications, no longer available, and

Your induction motor is various lumps of copper and steel with no magnetism.

It isn't a generator. No magnetism = no flux to cut = no output. It was designed
exclusively as a motor.

Thinking that adding a capacitor will make it a generator is a joke.

I suggest you acquaint yourself with some knowledge of science.


Graahm

 

[Tim Wescott]

Doug Goncz wrote:




Your induction motor is various lumps of copper and steel with no magnetism.

It isn't a generator. No magnetism = no flux to cut = no output. It was designed
exclusively as a motor.

Thinking that adding a capacitor will make it a generator is a joke.

I suggest you acquaint yourself with some knowledge of science.


Graahm

Induction machines will generate electricity if you turn excite them
with their designed AC frequency and voltage, then turn them at faster
than their synchronous speed -- the torque/speed curve is symmetrical
around the synchronous speed and the power output = power input - losses.

The notion of using a capacitor, in my opinion, is highly questionable.
An induction machine used as a generator _does_ appear to by highly
inductive, and they are often accompanied by parallel capacitance, and
in theory you could keep it going with the right capacitor, but I'm not
sure that it'll self-start in theory and I highly doubt that it would in
practice, unless it's purpose-built (i.e. _not_ a ceiling fan)*.

Such machines are even in use commercially -- before fancy inverters
they were quite popular with wind turbines, because it's a fairly simple
machine that doesn't need to be driven at exactly the synchronous speed
to be hooked up to the power grid. I have no idea how many there are
out there now.

--

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

* Diagram that sentence, please.

 

[Pooh Bear]

Induction machines will generate electricity if you turn excite them
with their designed AC frequency and voltage, then turn them at faster
than their synchronous speed -- the torque/speed curve is symmetrical
around the synchronous speed and the power output = power input - losses.

I think the big issue here is the *if* you correctly mention. The OP's link suggested
that residual magnetism is sufficient to 'get it going' - then explained how to fix it
if not so - lol.

No initial magnetism = zero output.

The notion of using a capacitor, in my opinion, is highly questionable.
An induction machine used as a generator _does_ appear to by highly
inductive, and they are often accompanied by parallel capacitance, and
in theory you could keep it going with the right capacitor, but I'm not
sure that it'll self-start in theory and I highly doubt that it would in
practice, unless it's purpose-built (i.e. _not_ a ceiling fan)*.

The link suggested that the capacitor would provide excitation current IIRC.

Such machines are even in use commercially -- before fancy inverters
they were quite popular with wind turbines, because it's a fairly simple
machine that doesn't need to be driven at exactly the synchronous speed
to be hooked up to the power grid. I have no idea how many there are
out there now.

Why not simply get a vehicle alternator from a scrap / wrecker's yard. They are
designed to generate power. I assume a small current is likely to be availble for the
excitation coils given the application.


Graham

 

[Paul Hovnanian P.E.]

I think the big issue here is the *if* you correctly mention. The OP's link suggested
that residual magnetism is sufficient to 'get it going' - then explained how to fix it
if not so - lol.

No initial magnetism = zero output.
Correct.


The link suggested that the capacitor would provide excitation current IIRC.

Its sort of a bootstrapping process. But it might not work with an
'impedance protected' induction motor (even if there is some residual
magnetism present). The higher winding inductance in such a device will
result in a greater reactive power demand for excitation and a larger
capacitor.


Hooking up to the power grid solves the excitation problem and
eliminates the need to bootstrap an induction generator to get output.

Why not simply get a vehicle alternator from a scrap / wrecker's yard. They are
designed to generate power. I assume a small current is likely to be availble for the
excitation coils given the application.

Yes. Since vehicle alternators have DC fields, they tend to have pretty
good residual magnetism. If the OP doesn't need much power, there might
be smaller alternators available for motorcycles.

 

[Joerg]

Hi Tim,

Somehow I think that the DOD is going to view gasoline for a motor as
being less expensive than C-rations for a 20-year-old. From a
watts/dollar standpoint it doesn't strike me as a winner.

Agree. I believe this whole idea will be outfoxed by a fuel cell
solution anyhow. Especially when considering the weight and size of a
ceiling fan motor. Just my 2 cents.

Regards, Joerg

 

[Doug Goncz]

Lessee. 17mm bore single row shielded ball bearings, or an alternator
out of the nearest parked car. Hmm.

Y'know, I bet the alternator will be easier to find.

The bearing will be eaier to supply.

Quoting me:

For what? Bicycle shock troops?

Essentially, yes, but I don't know what a shock troop is or how it
differs from the infantry. Perhaps this is a rhetorical term.

Yes, externally excite it with 60Hz, 120VAC.

The web page says you don't have to.

We told you that, too, in
your last thread. Once you get your inverter going you'll have enough
components that the MTBF of your assembly will be _much_ lower than the
alternator out of the nearest parked car.

I had a DC generator and a capattery. Two or seven components,
depending on how you count. There was no problem accumulating energy
and driving and inverter. This is simpler. DC supply for DC loads, AC
supply for AC loads. Pedal power for stationary use and low gears,
road power for capturing the 90 percent of potential energy lost to
heating the air behind the bicycle as it descends a hill. I believe I
can capture 50 percent of that 90 percent.

Somehow I think that the DOD is going to view gasoline for a motor as
being less expensive than C-rations for a 20-year-old. From a
watts/dollar standpoint it doesn't strike me as a winner.

MREs are overhead. Gasoline is a direct cost. Currently troops need
energy for nav, com, and vision. Batteies are heavy and take time to
be recharged. Primary batteries simply get thrown away. Secondary
batteries have to be cared for.

I can charge the caps on this bicycle to 9 WHr in 9 seconds at 625
amps to start, with jumper cables. This is about as quickly as a
soldier can get a drink of water.

I can cut and weld metal with these capacitors. You can't do that with
a battery.

Currently, half of the space in the resupply HUMVEE (HMMWV) is taken
up by batteries of many different kinds. It's simpler to just load up
with food and bullets, and when bullets aren't being fired, to just
load up with food and go.


Doug

 

[Rich Grise]

Quoting me:

Essentially, yes, but I don't know what a shock troop is or how it
differs from the infantry. Perhaps this is a rhetorical term.

I'ts a double-entendre[sp?]. "Shock troops" are like blitzkrieg soldiers,
i.e. shock as in surprise attack. Or, kids on bicycles with cattle
prods would be "shock troops" as in electric shock. Get it?

You may groan now.

Cheers!
Rich

 

[Tim Shoppa]

Batteies are heavy and take time to
be recharged. Primary batteries simply get thrown away. Secondary
batteries have to be cared for.

My gut feeling is that the best solution for this is something like
the methane-powered fuel cells that are coming out of the labs and
into commercial use now.

I can cut and weld metal with these capacitors. You can't do that with
a battery.

You've never dropped a wrench across a truck battery, I see . Even
a D-Cell NiCad is something to be respected.

Tim.

 

[Doug Goncz]

You've never dropped a wrench across a truck battery, I see . Even
a D-Cell NiCad is something to be respected.

Yes, I have. You can't cut through a lock with a pack of D cell. They
put 10 amps into a short.

I'm getting off topic.

What do I need to do to make my ceiling fan motor into a generator?

Rewind it?

Doug