I did not connect any load to the Voutput when first turned out to test it after assembled the board. I realized it after the fact and now it does not seem to work as I have anticipated and not really sure if that caused a problem. Output voltage measurement is about 46 volt which is 10 times lower than what I have in mind with 10K load connected to Vout. Output voltage is regulated at about 46V with input varied from 70V to a few hundreds volt. The weird thing is that when I increased or decreased the output load from 10K it changed output voltage a lot. In simulation using LTspice the Output voltage should be 457 volt with input of about 480 volt and more regardless of the output load. Any suggestions?
Your board are rock stable regardless input and load current variation. I have not tested out the overload current feature yet. One thing I noted to watch out for (just for reference purpose in case someone do the measurement) if one takes a voltage measurement at R11 the voltage will be impacted by the loading input impedance of the multimeter. At first I did not pay attention to it and wonder why the output dropped 28 volt (in my case) when making measurement there.
Just completed testing all features of the power supply today. Input is about 470-485V. Regulated Output is 455V with varying load from 100mA to 300mA. I also tested out the overload feature and the circuit shut downed at about 310mA as expected and turned back on after I decreased the load current and activated the momentary switch feature. It worked great.