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Background: I was looking at a spec sheet for a round metallized polypropylene film capacitor that gave two different current values for the "IRMS at 100 kHz -70 deg C" and the "Peak Current"

I'm planning on using a pulsed power system that produces 300 A pulses that last for 27 uS and occur at a frequency of 10 Hz. The IRMS at 100 kHz given was only 13.5 A, while the peak current was 432 A.

Question: What's the difference between the two? Based on the specs given, will the capacitor likely be able to handle the 300 A pulse I described?

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\$I_{RMS}^2*ESR=P_D\$ determines temperature rise.

Peak current is determined by destructive forces between plate foil on dielectric for a specified time duration.

Both need conservative margins for reliability.

You are responsible for correlating your design over all environental stresses and tolerances to the Do Not exceed limits of the component. Keep in mind how Mil-Std-883 MTBF is computed and what your expectations are (specs).

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