Bifilar pancake coil overunity experiment

[F6FLT]

Hi Tinman

If you move a probe to measure either Pin or Pout, you change the configuration. The capacity of the probes is significant in the process.
The three probes must be connected at the same time. Is that the case?

[ayeaye]

Two probes are connected at the same time, as i understand. Two separate measurements, one for measuring input power, and the other for measuring output power. I think this is a good way of doing it, and decreases error.

Why two probes when measuring output power, it's because the voltage on R2 then will be calculated in math channel from two voltages. Good in that is that the oscilloscope's ground is always the same as the function generator's ground.

[F6FLT]

Therefore the measure can be irrelevant.
If the scope has only 2 channels, at least a third probe should be always connected to the device and terminated at the other free end by a 1 Mohm resistor.

[ayeaye]

at least a third probe should be always connected to the device and terminated at the other free end by a 1 Mohm resistor.

I think he uses 10 times attenuation probes, that's a good way to do it and all i can say by now about it.

I see however one problem.

[ayeaye]

at least a third probe should be always connected to the device and terminated at the other free end by a 1 Mohm resistor.

I think he uses 10 times attenuation probes, that's a good way to do it, all i can say by now about it.

Tinman, i see however one problem there.

The voltage calculated on R2 will be inverted too, but this doesn't matter, as what interests us is the square of its rms.

The problem is though, the voltage measured on R1 is inverted, because it is not measured in the right direction, considering the direction of the current. But, the ch2 in the input power measurement is not inverted. Yet, it is used in the math channel calculation not inverted, math channel is calculated simply as ch1 * ch2. One can see it too, ch2 represents current there, and the circuit as it has been known, is capacitive, that is current should precede the voltage, but on that oscilloscope image it lags the voltage.

No hell, it seems that you are right, ch1 * (-ch2) is - ch1 * ch2, also when calculating math channel. Ok, i pointed out that the ch2 is not inverted, as it properly should, we cannot see the channels in the right phases, the calculation though seems to be right.