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**mbrownn** · 10-01-2011, 04:25 AM

Measuring efficiency

To calculate a motor's efficiency, you must measure its mechanical output power and divide it by the electrical input power.

It is interesting to note what efficiency is claimed for CD servo motors that are just ordinary DC motors but powered with pulsed DC under pulse width modulation.

The claims are typically 70 to 95% efficiency but if you power the same motors with plain DC you find their efficiency is only half that.

There is something fundamental that people need to understand here, the apparent gain in efficiency is because the current from the field collapse is is passed back to the motor via a diode across the motor terminals and in effect the current is being used twice.

http://homepages.paradise.net.nz/bha...les/esc_sw.gif

If we use a higher efficiency DC motor of 70% efficiency and run it under PWM with 50% duty cycle we can achieve up to 140%. Note that this is only obtained under optimum conditions.

I think this method of improving the efficiency of a motor is key to achieving a self running motor. It is possible

**Farmhand** · 10-01-2011, 04:58 AM

Originally posted by mbrownn View Post

Measuring efficiency

To calculate a motor's efficiency, you must measure its mechanical output
power and divide it by the electrical input power.

It is interesting to note what efficiency is claimed for CD servo motors that
are just ordinary DC motors but powered with pulsed DC under pulse width
modulation.

The claims are typically 70 to 95% efficiency but if you power the same
motors with plain DC you find their efficiency is only half that.

There is something fundamental that people need to understand here, the
apparent gain in efficiency is because the current from the field collapse is is
passed back to the motor via a diode across the motor terminals and in effect
the current is being used twice.

http://homepages.paradise.net.nz/bha...les/esc_sw.gif

If we use a higher efficiency DC motor of 70% efficiency and run it under
PWM with 50% duty cycle we can achieve up to 140%. Note that this is only
obtained under optimum conditions.

I think this method of improving the efficiency of a motor is key to achieving a
self running motor. It is possible

That may be so but if the electrical output is all that is being loaded then the
electrical load is the only load.

I am referring to a machine that is run to produce an electrical output only.

In my opinion any output that is not used to power the load is a loss. And
should be measured as loss. Only the useful output to power a load is useful.

So in my opinion if a motor generator takes 100 watts input to produce 50
watts useful output it is 50 % efficient, not 100 %, as the working efficiency
calculation would make it as far as I can tell.

50 % useful power means 50 % losses so the working efficiency would always
be 100 %.

That is what I'm trying to say.

The mechanisms used to run the machine are irrelevant, as is what the
current does after entering the circuit to what I am saying about overall and
working efficiency.

But I do see your point current can be used to create a field and recovered
mostly, I think I agree with that.

I'm just talking about the different calculations between total efficiency and
working efficiency.

I think apparent power consumed and real power consumed are another matter.
But also very relevant to the over 100 % efficiency thing.

Cheers

**mbrownn** · 10-02-2011, 08:23 AM

Yes I agree but lets look at this.

If we have a 70% efficient 100w motor running with PWM at the correct frequency we can get a measured mechanical power of 140W at the motor shaft. with a 70% efficient generator on that motor we get 98W. Now do you see why they make motors and generators with real efficiencies of 70% or less.

In the real world with resistances in the connecting wires and friction in bearings and gearboxes the problem is worse.

So if we take our 70% efficient motor on PWM and recover the coil collapse to a capacitor we get 70w of reusable energy that we can use to power the next pulse. So after the initial pulse we are only topping up the capacitor with 30 watts. now our motor is giving the same 140W of mechanical power as before but we are only powering the losses ie 30w. If we now connect our generator which gives 98w and have further system losses of 50% we still have 49w to power our motor giving an excess of 19w. Easily achievable.

Why is it that we haven't been able to do it? Ill tell you.

A motor is only 70% efficient at one given set of conditions and at all other conditions it is less than 70%, the same is true for a generator so in reality our motors and generators are running with around 35% efficiency most of the time.

Now lets do the math again 100w motor at 35% efficiency with PWM gives us 70w mechanical power with 30w recovery so our input power will be 70w and our generator will give 49w so even with no other losses we cant run our motor with the generator output.

The solution is running the motor and generator at their optimum performance, so the motor and generator have to be matched. With PWM it is relatively easy to get close to optimum with the motor but we have to have a generator that is matched to the power of the motor and they are not readily available. The rated power of the generator has to be exactly that of the output of the motor, less its efficiency and the generator has to be loaded with that power. Not only that but the rated speed of the generator has to match the rated speed of the motor, so it is a little more complicated than bolting them together.

Efficiency is everything and the equipment available off the shelf is designed to not be compatible. The purpose of http://www.energeticforum.com/renewa...tml#post143009 is to provide a means to balance the mismatch of the components by allowing the motor to run at higher voltage and speed, yet at the same power matching the generator requirements.

Again the generator has to be run at or close to its optimum or the efficiencies will cause the system to drop out of overunity. That's why the Lockridge device had to have a fixed load as a big deviation would cause a problem.

Do you see what I am saying?

**Farmhand** · 10-02-2011, 09:13 AM

Yes I can see what you're saying. Charging up the run capacitor with the
magnetic field energy from the previous cycle then topping up the losses.

That all sounds good, the motor could maybe do what you say, I think.

I'm not sure I agree with "all" of what you're saying, I need time to digest this
post and the other one in the other thread, but please bear with me,
I don't want to misunderstand.

I'll draw some pictures and and see if
I can visualize the system.

......

Umm What kind of motor ?

**mbrownn** · 10-02-2011, 09:52 AM

permanent magnet DC motor, unmodified

**Farmhand** · 10-02-2011, 10:22 AM

The first think I thought of was if the motor is an induction motor then some
current will be induced in the closed armature coils. Transferring energy there
by induction I guess. Do modern induction motors have capacitors in the
armature circuit ?

In this Book Chapter XXI Page 101 is a motor with one.
Probably standard practice.

Anyway
This is what I drew, Is this something like you mean. Have you modeled this
(simulator) ?

Uploaded with ImageShack.us

This is a simplified drawing. There could be two sets of two opposite series
connected coils I think. I drew adjustable cap and inductor only because as
you have said they would need "sizing". I'm imagining four separate phases
with switch one switching on two phases with the possibility of the sw1
phases overlapping the sw2 and sw3 phases.

Looks like a resonant charging circuit for a motor with motor coil recovery to
me. And looks like a very good idea also. I imagine the magnetic field could
move the motor and be recovered with some loss. Not sure if diodes are
sufficient though.
I wonder how well something like that would perform. I wouldn't like to speculate too
much with numbers until some tests were done in some scale at least.
Interesting.

..

**kcarring** · 10-02-2011, 10:28 AM

Originally posted by mbrownn View Post

It is interesting to note what efficiency is claimed for CD servo motors that are just ordinary DC motors but powered with pulsed DC under pulse width modulation.

The claims are typically 70 to 95% efficiency but if you power the same motors with plain DC you find their efficiency is only half that.

There is something fundamental that people need to understand here, the apparent gain in efficiency is because the current from the field collapse is is passed back to the motor via a diode across the motor terminals and in effect the current is being used twice.

Do inertia and momentum have a part in the extra efficiency? If I measure a machines output energy over time, and that machine is constant driven, versus pulsed, where there is no "coasting", am I in fact losing out on available output from inertia and momentum?

**mbrownn** · 10-02-2011, 10:45 AM

Originally posted by kcarring View Post

Do inertia and momentum have a part in the extra efficiency? If I measure a machines output energy over time, and that machine is constant driven, versus pulsed, where there is no "coasting", am I in fact losing out on available output from inertia and momentum?

When PWM is set up correctly a DC motor, it is driven all the time, inertia and momentum are not in the equation but it may play a factor although I am unaware of it. In the original Lockridge device it was a part of it as we could not get a high enough frequency with the commutator.

**mbrownn** · 10-02-2011, 10:49 AM

Originally posted by Farmhand View Post

The first think I thought of was if the motor is an induction motor then some
current will be induced in the closed armature coils. Transferring energy there
by induction I guess. Do modern induction motors have capacitors in the
armature circuit ?

In this Book Chapter XXI Page 101 is a motor with one.
Probably standard practice.

Anyway
This is what I drew, Is this something like you mean. Have you modeled this
(simulator) ?

Uploaded with ImageShack.us

This is a simplified drawing. There could be two sets of two opposite series
connected coils I think. I drew adjustable cap and inductor only because as
you have said they would need "sizing". I'm imagining four separate phases
with switch one switching on two phases with the possibility of the sw1
phases overlapping the sw2 and sw3 phases.

Looks like a resonant charging circuit for a motor with motor coil recovery to
me. And looks like a very good idea also. I imagine the magnetic field could
move the motor and be recovered with some loss. Not sure if diodes are
sufficient though.
I wonder how well something like that would perform. I wouldn't like to speculate too
much with numbers until some tests were done in some scale at least.
Interesting.

..

I dont know anything about induction motors so cant say.

Not quite, I have sent you a schematic

**Farmhand** · 10-03-2011, 02:14 AM

Back on topic. Efficiency calculations

Ok I want to stay on topic here, so I've just realized it is not really possible to
measure an input voltage for a device that operates from one wire, and so the
input power also seems impossible to measure.

Any idea's how the input power can be calculated for a setup with only one
input wire ?

This is related somewhat to using the AC grid power as a power source. If
efficiency can be calculated by measuring the input to a device from the Grid AC
as a source just after the socket, then efficiency can be calculated from any AC
source, without considering the cost of making available the AC power
source, and only using the input power to the device from the AC source as
the input for the efficiency calculation.

Any thoughts on this.

**Farmhand** · 10-04-2011, 07:03 PM

So nobody wants to comment on the actual efficiency of the machine in the
borderlands video ?

The Rotary Parametric Transformer.

Well that makes sense because no one wants to see that although it is
claimed to have a working efficiency of 108 % the real total efficiency
is only about 52 %. And considering the measurement error + or - 5 % then it is
only 103 %. In my opinion the 3 % is probably a measurement error as well
considering they were reading analogue meters. In my opinion the working
efficiency can only ever be 100 % as I show in the first post of this thread.

That device was outputting 182 watts for an input of 348 watts. That is 52.3 % efficient.
Everything else is just playing with numbers.

And yet I refer people to this post.
http://www.energeticforum.com/159983-post473.html

Quote:
Originally Posted by vrand
Hi Eric

Can you please suggest a simple experiment/device where we can build a free energy device to power our homes and cars? Around 10 kw power output?

Cheers Mike
Here is Eric's reply on his Yahoo egroup n6kph forum:
n6kph : N6KPH

Thank you Eric

Cheers Mike

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

From: Eric Dollard
Sent: Friday, September 30, 2011 1:55 PM
To: n6kph@yahoogroups.com
Subject: [n6kph] Response to the forum

Santa Barbara Rotary Parametric Transformer, tested gave transformation
ratio, power it to power out, of 108% +or- 5% error of measurement. It
works, see video.

This does not add up. Eric has recommended a 52 % efficient machine as the best
machine to build for free energy.

I am not interested in "working efficiency" as my first post shows working
efficiency is always 100 %.

In my opinion the working efficiency of the rotary parametric transformer is
100% not 108% and it's real efficiency is 52 % it is the real efficiency that is
the real efficiency.

In the video it is stated that the output was 182 watts and the input was 348 watts
the difference can only be losses and so when calculated as all output as
output and all input as input and all the difference as losses the working
efficiency is 100% as it can only be, logically.

What does this tell us ?

What it tells me is people don't want to acknowledge truth.

We are looking for efficiency's of over 100 % total efficiency. Not over 100%
working efficiency. The working efficiency means practically nothing.

Working efficiency is being used by "some" to claim Overunity

.

Although in the video the difference is clearly stated and no such claims are
made in the video. However far too much importance is given to the working
efficiency (in my opinion) simply because it showed a very dubious figure of
108 %, which looks good, and sounds cool.

But the fact remains the Variable reluctance transformer has an efficiency of
52.3 %. Not 108 %, as some have assumed. I repeat the difference is stated
in the video.

In my opinion many people are under the impression that the real total
efficiency of the variable reluctance transformer is 108 % when it is not, it's
real efficiency or total efficiency is 52.3 %.

Cheers

**Shadesz** · 10-04-2011, 07:25 PM

Yes it is important to distinguish the two. Personally I will leave that responsibility to the FE enthusiast. If they can't tell the two apart they will just be fooling themselves and wasting time.

My goal is a device that can power itself plus provide extra working energy. In this case I would consider it free energy.

**Farmhand** · 10-05-2011, 01:25 AM

The way I see it when we turn on a light, we do it to get the light, any heat
produced is a "loss". Same thing when we use a heater, if the heater makes light,
that is a "loss", or sound. These are not a "wanted and useful" dissipation of
energy so they are losses. And should be calculated as losses in an efficiency
calculation.

Also it takes dissipation of energy to make available the grid power at the wall
socket, so the energy dissipated in the process of making available the power at
the wall socket should also be calculated and factored as a loss in any efficiency
calculations done when grid power is used to power a device when determining
it's efficiency. Just paying for it is not good enough.

The only real way is to start with a source of stored energy and go from there.

Cheers

**Farmhand** · 10-05-2011, 07:54 PM

Hi all, I was expecting some comment on this since it seems to be we are all
doing stuff that requires efficiency calculations.

I'm waiting for someone to say it's OK to measure "total" efficiency for a
device powered from the grid and measuring between the socket and the device.

A device that appears efficient when powered from grid power might not look
so efficient during a blackout when you must provide the energy to create
you're own AC power source.

Seems to me that is not the correct way to do it. Seems to me the best easiest
and most convincing way to measure power is to measure DC power out of a
stored energy source (battery or capacitor) and into a stored energy source or
a DC load.

In all reality though what I want to achieve is an increase of stored energy after
powering a load.

Cheers

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