Partnered Output Coils - Free Energy

[partzman]

Partzman,

Have you considered moving, or adding another, Rs between the sine out and the CH1 test point and using that Rs position to determine input power? (using the CH2 probe to measure the sine out level)

PW

PW,

Good suggestion and yes I have done that in the past. However, placing the sense resistor in series with the signal source requires differential measurements. With the low voltage levels across the sense resistor at these power levels, the accuracy was not as good as the ground referenced connection. By using this method and also using properly de-skewed current probes on the input, I was able to confirm that the amplitude and phase of input and output current sensing was identical. 

I think I know your concern in the fact that there is possibly a source or loss of current that is not being measured that is affecting the overall measurements. That was my concern in my early experiments with circuits of this type and by using the methods above, I was able to conclude that the ground referenced high quality Vishay resistors worked the best even up to 10Mhz or so. This makes sense as the circuit must adhere to Kirchhoff's law so unless there is some outside stray coupling, the voltage across the grounded Rs should accurately represent the current from the source.

partzman

[picowatt]

PW,

Good suggestion and yes I have done that in the past. However, placing the sense resistor in series with the signal source requires differential measurements. With the low voltage levels across the sense resistor at these power levels, the accuracy was not as good as the ground referenced connection. By using this method and also using properly de-skewed current probes on the input, I was able to confirm that the amplitude and phase of input and output current sensing was identical. 

I think I know your concern in the fact that there is possibly a source or loss of current that is not being measured that is affecting the overall measurements. That was my concern in my early experiments with circuits of this type and by using the methods above, I was able to conclude that the ground referenced high quality Vishay resistors worked the best even up to 10Mhz or so. This makes sense as the circuit must adhere to Kirchhoff's law so unless there is some outside stray coupling, the voltage across the grounded Rs should accurately represent the current from the source.

partzman

Partzman,

Similar to my earlier suggestion to Tinman, an analysis using a single cycle (or half cycle) N-cycle burst to excite the circuit  would be interesting.

Somewhat like ringing a bell...

PW

[partzman]

Partzman,

Similar to my earlier suggestion to Tinman, an analysis using a single cycle (or half cycle) N-cycle burst to excite the circuit  would be interesting.

Somewhat like ringing a bell...

PW

PW,

Good suggestion and will do that sometime in the next few days as time permits. BTW, I just noticed a typo in the description of the Vishay csr on the schematic that should read ".5 x 2 = 1 ohm" not ".05 x 2 = 1ohm".

partzman

[picowatt]

PW,

Good suggestion and will do that sometime in the next few days as time permits. BTW, I just noticed a typo in the description of the Vishay csr on the schematic that should read ".5 x 2 = 1 ohm" not ".05 x 2 = 1ohm".

partzman

Partzman,

Note that the Vishay series resistors used for Rs are only specified as being less than .08uHy.

PW

     

[partzman]

Partzman,

Note that the Vishay series resistors used for Rs are only specified as being less than .08uHy.

PW

     

PW,

Yes, they are spec'd at <80nh but honestly when I've tested them with the equipment I have available, I find no measurable inductance. They are also spec'd with no noticeable ringing using a 1ns risetime pulse but they are pricey!

Caddock also makes good non-inductive low valued resistors in smd spec'd at 5nh-10nh but they are only available on special order. They also have some reasonably priced radial packages off-the-shelf rated at 20nh but I've not tried these at this point.

partzman