Electronic – How to create a 120V-175V Variable Frequency Generator

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I am dealing with a system that requires me to drive a capacitive load at 120V-175Vrms, AC square/sine wave at two frequencies: 50Hz and 2000 Hz @ Ipeak = 100mA. I am currently trying to find the best way to achieve this.

I had originally used a HV driver chip that had a supply of 300V, modulate the output to create a 0-300V square wave, high pass filter it, and finally send it to my load. The issue with it was how I generated my power supply. I had used a voltage doubler + voltage divider to obtain 300V from 120VAC in. As you all know, voltage dividers are terrible for usage a power supply from a variable load.

My next plan was to instead use a high voltage op-amp with square wave input, and configure it like a comparator to create a AC square wave, which would drive my load. The issue is that again the power. Here I tried to implement a SMPS from 12V to 175V, but the problem was the efficiency was terrible and thus I could not find any economical 12V power supplies to adequately drive my load.

So my question to all of you: is there a better way to generate an AC sine/square wave of 120-175Vrms @I=100mA? Or is there easy solutions to the problems I have faced in my implementations?

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