STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM

[broli]

Your load is just a simple passive high pass filter. The current proble should not give a negative reading at 41 Mhz, unless your current probe is faulty.

Also, you were using a pulse source to power the circuit. A pulse waveform contains a lot of RF signals, all of which carry power at above the fundamental frequency. A current probe is  in effect a low pass filter. There is a possibility that your current probe has "filtered"  out some of those RF signals!

If the current in your bifilor coil went negative at 41 Mhz for no reason, then please show us the input current waveforms at that frequency range.

I am still skeptical of the accuracy of your current probe.

This called going backwards. The whole point of the current probe was to end the discussion and debate about measuring voltage across a resistor to calculate current, and to move forward. Yet now you argue that a 3000$ current probe is faulty?

I suggest you propose experiments, share circuits or do something else for the sake of advancing rather than going back to square one.

Closing the loop is a big goal but before that I would like to see how this effect scales up for instance in the watt range.

[Omnibus]

@All,

Recall, I did a comparison with measuring current by dividing the resistance of a metal oxide resistor into the voltage drop across it and compared it to the current measured with the current probe. That was during the times when parasitic inductance across the resistor was still a concern (that was the reason for me getting a high end current probe). The current measured in those two ways coincided (signals overlapped). That was sort of a calibration test and it makes the "low pass" filter argument moot. The current measured with the current is all the current which passes through the active resistance R. This is already firmly established experimentally.

[Omnibus]

@broli,

I'd like to go further but, unfortunately, I'm limited now by the parameters of the pulse generator as well as the active elements I have at hand if I wanna do some scaling. Would be good if we can think of self-sustaining by using what we have now. Wonder if that would be possible in view of the huge losses along the way?

[blueplanet]

A Hall effect CT is a low pass filter. Why don't you just show us the input/output current waveforms in the neighborhood of 41 MHz? Perhaps, we can learn something from there.

@blueplanet,

Start here:

Explain why a Hall effect-based current probe good for DC to >120 MHz Bandwidth should not give negative reading within that frequency interval if the current indeed has negative values (as is the case in this study).

This may also give you a clue as to why the rest of your concern (the probe being in effect a low pass filter) isn't viable.

[blueplanet]

I presume your pulse source is not sinusoidal. And I presume it is not 555 type, because 555 would unlikely end you up with 100 Mhz.

But all the waveforms you showed us were sinusoidal. If there is no low-pass filtering, what gives you a sinusoidal waveforms?

@All,

Recall, I did a comparison with measuring current by dividing the resistance of a metal oxide resistor into the voltage drop across it and compared it to the current measured with the current probe. That was during the times when parasitic inductance across the resistor was still a concern (that was the reason for me getting a high end current probe). The current measured in those two ways coincided (signals overlapped). That was sort of a calibration test and it makes the "low pass" filter argument moot. The current measured with the current is all the current which passes through the active resistance R. This is already firmly established experimentally.