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Keppe Motor Overunity ClaimedThe Brazilian group that has been reporting super efficiencies in their motor now posts evidence that they have surpassed 100% efficient, which they say proves their claim that they are harnessing space energy.
by Sterling
D. Allan
I see a couple of problems with their report, one of which argues the actual
output as being lower, while the other argues for the output being greater than
reported. # # # Response from STOP to above questionsOn February 18, 2009 4:00 PM Mountain, Eduardo Castelγ Nascimento wrote: Below
are the answers to the points you mentioned: 1)
When they report the rpms, Cesar's voice says "920 rpm" but the video
at that point is actually more like 912 rmp, and jumping +/- 10 of that, not
stable. The measurement accuracy of the various probes is not that great;
and combined, the standard deviation is probably greater than 15%, thus not
giving a definite conclusion of overunity. / 60W
fan load not factored? Response:
If
you consider the average per second it is not 912 RPM, it is 916.13 RPM (see
attached file). So, from 920 to 916.13 the difference is 0.42%, almost
irrelevant. In the video, you will see that Roberto is holding the switching
element with his hands, this causes a RPM variation. With a well machined and
engineered motor this variation would be eliminated. Again, a difference of 4 or
8 RPM does not represent a relevant factor in this size of blade. If we consider
the lowest RPM in the video, 900, overunity still occurs, decreasing from 1.15
to 1.12. The standard deviation in this video is 5.86 RPM, much less than 1%,
but again, we do not think that this variable is so relevant, not even close to
the 15% you mentioned. 2)
Maybe I'm missing something, but their math doesn't seem to take into account
the 60-Watt equivalent resistance generated by the fan, which would result in
more output than what is reported. Response:
There is a misunderstanding in relation to the method utilized to measure the
torque of the Keppe Motor on the video. We did not use the Pony Break
method, because this method is not accurate enough to test motors. We used a
method similar to the Electric Dynamometric Brake, which is one of the most
precise and utilized methods in the mechanical industry to measure torque. The
electric dynamometric brake is conceived to carry out engine load tests in where
fast regulation and high precision is necessary. The only difference in our
measurement is that used a fan blade to generate load instead of electrical
resistors, generally used in this method. In other words, we used a mechanical
load instead of an electric load. The result is the same. In this method, when
the fan blade is spinning in one direction, it exerts on the body of the motor
an opposite force with the same intensity (Newton's third law of
action-reaction) and the body of the motor will tend to rotate as well, thereby
causing the 20cm-arm attached to it to press the plate of the weighing
scale in the same proportion of the fan blade spinning at a specific speed
(in the case, 920rpm). This method is one of the best because the internal
frictions cancel out (even if they are significant) and do not influence the measurements
and consequently the calculation. * * * * Measurements, Discrepancy, Maybe OverunityFebruary 18, 2009 8:22 PM "David Jenkins" <djenkins {at} garlic.com> wrote:
I've massaged the numbers that the Keppe people provided in I placed quote marks around "34" because the Simpson VOM is a damped analog meter whose accuracy rapidly deteriorates when the current is not d.c. The Keppe motor is a pulse motor whose duty cycle is very low (probably less than 10%). This means that the meter reading is lower than the true average. This could easily be 10% or more. To test this, I used a Triplett model 625 VOM, with mirrored scale, very similar to the meter in the video. I placed a 10-volt peak pulse, 1 mSec in duration, at period of 10 mSec, across a 49.6-ohm resistor in series with the meter. This simulates the coil pulsing of the motor. Because the peak current is 200 mA and it is a 10% duty cycle, the meter should read 20 mA. However, the meter reads 18.5 mA. Thus there is a 7.5% error using my meter. Thus just based on the measured power levels, the motor can not be claimed over unity. However, the rotation of the fan blade does require power which the video does not measure. 920 RPM is roughly the normal speed for a room fan and could easily be several watts. It would be easy to measure the power required to turn the fan at that speed. It's a measurement that needs to be made for this video to have substantial credibility. My conclusion is that the motor could be over unity but the video does not provide adequate information for that determination. I find it interesting, and probably not an accident, that the motor is running from a 200 volt supply (The kit motor runs from a 9-volt battery). * * * * Problems with Set-upOn February 19, 2009 9:26 AM Mountain, Dave Squires <djsquires {at} ultraplix.com> wrote (in blue): ...Because the peak current is 200 mA and it is a 10% duty cycle, the meter should read 20 mA. However, the meter reads 18.5 mA. Thus there is a 7.5% error using my meter.An old Simpson analog meter will not give the right answer averaging pulses. There's too much error built in already at 3% for DC to start with. Then you have to watch out for parallax when reading the scale. Something to measure the area under the pulse is required to be accurate. THEN you can divide by the period to get a true duty cycle average. Of course the sampling rate has to be high enough if an A/D type system is used so the peak is not missed. The only possible reason for OU is that the pulse gets enough current into the coil that the discharge of the current is stretched by the time constant to give a bit of extra torque from the flux collapse. I could believe that it could be a tad OU, but they are doing things rather sloppily in my opinion. I know this can be done using pulse techniques, but direct pulsing with a HV supply is not the way to go about it. Well, of course. With the recommended number of turns (500 if I remember right) the CEMF voltage will be pretty high. It was clear to me just from a first reading that they really didn't know what they were doing. I was not impressed. * * * * Keppe-Related Coverage by PESN
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