I want to measure frequency of impulses of the current passing during the discharge of the capacitor. Basically I thought about two options:
a) detection by microphone (spark gap makes noise)
b) Hall effect sensor
Now question is which solution would be better to my design and how to apply it? What do I need?
Hall effect sensor + low pass filter + impulse width expander ?
How should I apply hall effect sensor? What use as impulse width expander? I want to make from impulses square wave so that AVR can see signal and can adjust IGBT triggering signal width to charge capacitor appropriately to desired discharge frequency.