I am a volunteer at a museum. My project requires a magnitude/phase comparator. The supply is half rectified 115VAC 400Hz. The input is half rectified 0-58VAC at 0 or 180 phase relative to the source. Both supply and signal are referenced to ground. When the input signal is in phase with the supply the output is proportional to the input. The output needs to range from 0-5VDC, and feeds an op amp (i.e. hi input impedance).
I think I need a high voltage small signal FET arranged as a source follower, with a voltage divider on the input. That is about the limit of my circuit ability with FETs. Any suggestions as to the source resistor and capacitor values, the gate resistor values, and the FET number?
--jon
I think I need a high voltage small signal FET arranged as a source follower, with a voltage divider on the input. That is about the limit of my circuit ability with FETs. Any suggestions as to the source resistor and capacitor values, the gate resistor values, and the FET number?
--jon