Hey Guys, I'd like you to take a look at the following circuit. It is powered by 3V or 6V. With 3V on the input you get 80V out and with 6V you get 200V out. I know that the transistor (JE200, not 2N3502) produces the AC signal and amplifies the voltage, but what does the transformer do? I want to power it with a 9V battery and have an adjustable potentiometer from 200V to 0V. Can someone explain how I calculate the correct potentiometer value? Thanks!