There is electrochromic film (which is some kind of capacitive load) that need to be driven with 50Hz alternating current, load voltage should be controlled in range 0-100V (with 8 or more fixed voltage levels or with continuous change in given range) by ARM processor with PWM or any other way.
Film segments of desired size have around 50KOhm impedance magnitude and should be driven by AC in order to function properly. Load power consupmtion is aproximately 0.001-0.01 watts at 100V.
I want to control many segments in parallel so per segment part of the circuit price and complexity are significant, so scheme with shared ac source design will be better.
The only idea i have for now is to produce low voltage alternating current with PWM and low pass filter and then use step up transformer to get high voltage output, but it looks over complicated for me and i'm not sure it will work at all.