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

[broli]

Now, notice this, the phase shift (which one may think is due to capacitance kicking in) whereby current is leading the voltage decreases with frequency but the OU effect increases. Indeed:

90kHz    2.8us
100kHz  2.08us
200kHz  1.8us
700kHz  0.328us

If we follow the capacitance theory it should be the opposite--the I-V phase shift should increase, indicating greater capacitance leading to a greater apparent OU. It seems the above is one piece of experimental evidence that goes against the theory that parasitic capacitance is being developed at higher frequencies which acts as a shunt and therefore the current we're observed and attributing to Ohmic losses is overestimated.

You should be careful with expressing the shift in absolute time figures. As you increase frequency the period shortens and any phase shift will shorten too. It's best to express the shift in percentages or degrees. A phase shift 1 sec in a period of 10 sec becomes 0.1sec in a higher frequency with period 1s. Both have the same shift but their time scale have changed.

[Omnibus]

You should be careful with expressing the shift in absolute time figures. As you increase frequency the period shortens and any phase shift will shorten too. It's best to express the shift in percentages or degrees. A phase shift 1 sec in a period of 10 sec becomes 0.1sec in a higher frequency with period 1s. Both have the same shift but their time scale have changed.

@broli,

That's true but, notice, I'm measuring the time difference with the cursors directly on the screen. I should have said that explicitly because the way I presented the pics it may seem that I estimated just roughly that deltat. The deltat measured is exact.

[broli]

@broli,

That's true but, notice, I'm measuring the time difference with the cursors directly on the screen. I should have said that explicitly because the way I presented the pics it may seem that I estimated just roughly that deltat. The deltat measured is exact.

Below you can see what I mean. The lower graph is just a higher frequency but it has the same angular shift, but if you measure the absolute time difference then it's smaller due to the higher frequency.
So it's more useful to calculate the angular shift using the equation in the image. To apply this on your data this would give:

90kHz    : 90.72°
100kHz  : 74.88°
200kHz  : 129.6°
700kHz  : 82.65°

[Omnibus]

@broli,

Please take a look at the upper right corner of the screen. You'll see two columns there. At the bottom of the left column (the third number down) you'll see the exact value of deltat measured with the two cursors. It indeed appears visually the way you've presented it but  measuring it with the cursors presents it in the actual scale along the x-axis. The numbers there in these two columns are the real values measured, using the actual scale.

[broli]

@broli,

Please take a look at the upper right corner of the screen. You'll see two columns there. At the bottom of the left column (the third number down) you'll see the exact value of deltat measured with the two cursors. It indeed appears visually the way you've presented it but  measuring it with the cursors presents it in the actual scale along the x-axis. The numbers there in these two columns are the real values measured, using the actual scale.

Yes we are on the same page there. What I'm talking about is frequency scale. You need to compare angular shifts and not the the times since you are comparing different frequencies. However you use those measured times to calculate angular shift, I hope that makes sense. What interests me most is the angular shift of 130°. This is a clear indication of more energy being put into the system.

But the most correct measurement is the integral one where instantaneous values are integrated over a time period like your graphs.