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Re: [TCML] RF Ground and Brass


Yes, Terry's value is 10Ap-p, 5Ap, 3.85A rms. Is that better? I simply grabbed the page to link in the post (simply to show several amps of base current) [I hope I still understand base current otherwise I will go back to school and shoot my the teachers and burn my books.]. I guess I should have deduced detail so I could have said "3.85A rms" on Terry's coil!

I don't know how many times now I have said "time dependent". At least 3 or 4 emails now. I've said all I can about that.

An rms value in the mA range: Is that Ambient temp dependent? Current dependent? BPS dependent? Energy dependent? Base current dependent? Lead length dependent? Wire size dependent?

Answer = All of the above.

Are you "so" sure mA range or is this just a number from Terry's email you listed?

Now your going to have to measure for yourself and deduce all of the above in the process.


OK, looking at Terry's paper, I see the waveform you refer to.  The Peak secondary base current is 5 Amps, not 10.  But I think you may have an incorrect understanding of RMS current.  If one has a _continuous_ sine wave with a peak current of 10 Amps, the RMS current is 7.07Amps.  But as you know, the secondary current in a disruptive coil is not continuous.  It has a low duty cycle of something roughly like 1%, and even during the bang-time, the amplitude envelope is very complex.  There is no simple conversion between the 5A peak current in Terry's waveform, and the RMS current.  The BPS, coupling, and quench time all factor heavily into the RMS current. There are ways to measure RMS current, the best being with a digital scope that does a lot of number-crunching over a time interval that includes both the bang on and off times.  Measuring the brightness of an incandescent bulb also works, because it has a sufficiently long thermal time constant to kind of average the current over the bang on and off times.  But the key is that you need to look at a waveform over a time interval where it repeats.  That's how a waveform with a peak current of many Amps can have an RMS value in the mA range.  You can't just look at the peak value and deduce the RMS value.  It's the RMS current that correlates to how much wire heating will occur.  If you're writing tools that purport to give RMS results, it's important to understand what that means.

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