Bifilar pancake coil overunity experiment

[Void]

Hi Brad.

What was the frequency of operation there? Was the scope set to 50nS per division? 13 MHz approx. ? ? ?
... or am I reading that wrong? Are you using non-inductive resistors for the CSR and load resistor?
It is looking like your load resistor R2 may actually be inductive, and if that is the case that could cause
the current reading across it to read considerably higher than the true resistive load current.

It is possible that Vin and Iin could be close to being in phase if the pancake coils are being driven
at a frequency that is close to a resonance point for them.

Also, see the attached picture of your latest test setup with some additions from me.
I have indicated three different currents: I1, I2, and I due to capacitive coupling back to the function
generator ground. All three of these currents are not equal in both magnitude and phase angle! These
are three different currents. The current returning to the function generator via capacitive coupling bypasses
the CSR R1. Your measurement of the input current therefore will not be accurate IMO.

It is for this reason that I said that I think using a current probe at the 'positive' output wire
of the function generator is probably the best representation of the input current for this type of setup,
assuming the current probe is reading reasonably accurately for both magnitude and phase angle.  However,
due to the complexities in making accurate measurements in this type of setup, I personally would still
not have a high degree of confidence in the accuracy of those measurements even when using the current probe.
That is just me however.

[ayeaye]

As much as i know, current in a single closed loop is everywhere the same, and its phase is the same.

If F6FLT or someone else points out some great difficulties in measurement, yes, oscilloscope is all about accuracy. My suggestion is then, measure some simple circuit, like a one containing only a capacitor, with similar frequency and voltages. Then simulate the same in LTspice, and see how great the error is.

[Void]

As much as i know, current in a single closed loop is everywhere the same, and its phase is the same.

Hello ayeaye. If you look at the diagram I attached above, it should be clear that such a circuit, where an open ended
coil is being driven from the generator, is not a 'single closed loop'. It is therefore not so straight forward
to make accurate measurements on such a setup.

[tinman]

Hi Brad.

What was the frequency of operation there? Was the scope set to 50nS per division? 13 MHz approx. ? ? ?
... or am I reading that wrong? Are you using non-inductive resistors for the CSR and load resistor?
It is looking like your load resistor R2 may actually be inductive, and if that is the case that could cause
the current reading across it to read considerably higher than the true resistive load current.

It is possible that Vin and Iin could be close to being in phase if the pancake coils are being driven
at a frequency that is close to a resonance point for them.

Also, see the attached picture of your latest test setup with some additions from me.
I have indicated three different currents: I1, I2, and I due to capacitive coupling back to the function
generator ground. All three of these currents are not equal in both magnitude and phase angle! These
are three different currents. The current returning to the function generator via capacitive coupling bypasses
the CSR R1. Your measurement of the input current therefore will not be accurate IMO.

It is for this reason that I said that I think using a current probe at the 'positive' output wire
of the function generator is probably the best representation of the input current for this type of setup,
assuming the current probe is reading reasonably accurately for both magnitude and phase angle.  However,
due to the complexities in making accurate measurements in this type of setup, I personally would still
not have a high degree of confidence in the accuracy of those measurements even when using the current probe.
That is just me however.

Hi Void

Yes,turns out these !so called! non inductive resisters become quite inductive after 2MHz-ok below that.

Swapping it out for a 1/2 watt carbon resistor made all the magical OU disappear 


Brad

[Void]

Hi Void
Yes,turns out these !so called! non inductive resisters become quite inductive after 2MHz-ok below that.
Swapping it out for a 1/2 watt carbon resistor made all the magical OU disappear 
Brad

Hi Brad. Ha ha. Ok, yes, it was kind of looking like that might well be the culprit when I
was looking over your test setup and measurement results. Have a happy new year guys!