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Re: New Coil



Original poster: "Gerald  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi Paul,

Dont really know what to say since I never have used a maxwell. I do find it curious that two maxwells in a row failed. The first one exploded and the second one cracked?? You did an optopsy on the second one and to me looked like a defect. Dont know if you were ever able to look at the first one. Since peak current doesnt seem to be a problem (at least spec wise). you might want to recheck the RMS current spec. Maybe heating is the culprit. You could estimate the RMS current by assuming peak sinusoidal current for the duration of the bang and average this out over the bang period (1/BPS). This would probably overestimate the RMS current by a factor of two. If you have a scope with a HV probe, you could try a third maxwell and see how the voltage across it changes as the variac is ramped up. JavaTC would give you a peak current and energy transfer time for your design for a quick calculation. I cant remember if you have a SRSG or static gap, but the scope should enable you to measure the real bang time given whatever notch you are quencing at and the real peak voltage you are subjecting the cap to. Then you can calculate a more accurate rms current.

Ipeak = Vpeak / sqrt (Lp/Cp)

Gerry R

Original poster: "Paul B. Brodie" <pbbrodie@xxxxxxxxxxxxx>

Gerry,
My 2 Maxwells measure 30.4nF and 30.0nF on my DMM. I haven't checked anything else.
Paul
Think Positive