Bifilar pancake coil overunity experiment

[partzman]

Itsu,

OK, thanks for re-running your test and I would conclude that for some reason your bifilar coil has a somewhat reduced Q or possibly some other problem that is affecting the overall performance.  For comparison I have attached  the test results of a pcb based pancake coil.  The schematic is identical to that posted by TK and yourself with  one exception, a mosfet driver is providing a symmetrical square wave pulse with a 20v peak to a 35uH inductor which resonates with the distributed capacitance between the windings.  The resulting 1.7 MHz sine wave seen on CH1(yel) is the reference measurement input waveform.

The load is 20 ohms and the CSR is 1 ohm both non-inductive.  The probe used for current sensing is attached directly to the CSR with an RF spring and probe tip.

In  the first scope pix below, CH1(yel) is the input waveform, CH2(blu) is the voltage across the total load of 21 ohms and CH4(grn) is the current through the 1ohm CSR.  The Math(red) channel is the calculated mean input power as measured between the vertical A&B cursors.  Statistics of the measurements are shown and continuously averaged over 16 cycles with a 1Ms sample rate for the horizontal window.

As seen, the mean input power in the Math channel ranges from 411.9mw min to 450.8 max.  The statistical average output voltage across the load is 4.94v rms resulting in a Pout = 4.94^2/21 = 1.162 resulting in an apparent COPmin = 1.162/.4508 = 2.58 and a COPmax = 2.82.

The next scope pix shows the data for CH4 to allow comparison between the Math channel and measurement results using the input voltage/current phase angle.

Here we see the CSR current is 234.5ma rms.  Therefore, the Pinmin = 98.01*.2345*cos(-88.91) = 437.2mw and Pinmax = 98.01*.2345*cos(-88.28) = 689.8mw.  This should illustrate the demanding requirement for phase angle accuracy and how it affects the input calculations.  So, we see an apparent COPmin = 1.162/.6898 = 1.68 and a COPmax = 1.162/.4372 = 2.66.

A pix is also attached of the pcb based coil assembly.

Regards,
Pm

[ayeaye]

Partzman, oh no, no mosfet. This thing leaks like hell. One should avoid using mosfet in any overunity experiments, unless one is ready to calculate the leakage.

Itsu, i see that the calculations are correct. The ch2 and ch3 are in phase, this enables to calculate power from voltage on both of them. Interesting why, as there is the coil in parallel with R1, looks like that the bifilar coil acts only as capacitor there. All calculations have to be done though during the whole cycle of the input voltage. I'm not sure that the range is selected, i don't see it, but then i don't know that oscilloscope.

The current leads the voltage there, should mean that the circuit is capacitive.

Itsu, i believe you did good work. This thing may not work, whatever, important is to measure power.

[itsu]

PM,

thanks for the detailed info, allthough you use 4.94V in your Pout calculations (Pout = 4.94^2/21) while the
screenshot shows a mean of 4.694 in the blue data, the COP still is high and similar as TK reports.

But indeed, a slight deviation of the phase has a big influence on the end result.


I have a second identical bifilar pancake coil which i will use to double check my COP = 1 results.
I cannot think of what the cause is for the low (61°) phase angle in my present coil.

Itsu 

[F6FLT]

Thank you, very important.

One thing though, the output power is (ch3 - ch2) ^ 2 / R1 + ch2 ^ 2 / R2 (root mean square average voltages of ch3 and ch2), you calculated ch3 ^ 2 / R1, but this makes output only less and COP less.

You're right, ayeaye. The measurement method is wrong, not only Pout but also Pin.

The output power is not equal to CH3²/(R1+R2) but is equal to Pout = (CH3-CH2)²/R1 + CH2²/R2 as you stated.
And the input current is not given by CH2 because current from R1 is added so Pin is wrong too.

(As I may be wrong too, please guys explain your method with Pout=CH3²/(R1+R2) while it's not the same current in R1 and R2).

For me, if you want use the voltage at R2 terminals to know the input current and have Pout=CH3²/R1 + CH2²/R2 and Pin=CH1*(CH2/R2) then you have to connect the probes this way:

[tinman]

You're right, ayeaye. The measurement method is wrong, not only Pout but also Pin.

The output power is not equal to CH3²/(R1+R2) but is equal to Pout = (CH3-CH2)²/R1 + CH2²/R2 as you stated.
And the input current is not given by CH2 because current from R1 is added so Pin is wrong too.

(As I may be wrong too, please guys explain your method with Pout=CH3²/(R1+R2) while it's not the same current in R1 and R2).

For me, if you want use the voltage at R2 terminals to know the input current and have Pout=CH3²/R1 + CH2²/R2 and Pin=CH1*(CH2/R2) then you have to connect the probes this way:

Power calculations of the circuit attached to your post cannot be calculated using a scope with common grounds,unless the P/in and P/out are calculated separately.

The only way to measure P/in and P/out at the same time,using a scope,is to have a scope with isolated grounds.

P/in should be calculated by voltage across the primary of the isolation transformer,and current through the primary of the isolation transformer,as it is part of the circuit,and where the FG is the source.