Hi I would like to know is it reasonable to make a astable multivibrator that is fed from about 325v dc , the rectified +filtered mains.? I understand that with the right transistors and resistors I will get some oscillation but the question is will i be able to get a nice square wave to drive some mosfets that would then drive a transformer primary? The idea is of a as simple as possible smps power supply not using any ic's or chips. So yes the question is can such an arrangement work efficiently and smoothly enough for it to be called a reasonable smps? I have done very much simulation before finalizing my schematic on multisim but the program is kinda weird sometimes as when I had one circuit with all the transistors and so and it worked very good the simulation showed a nice square wave. I had potentiometers set as reostats in the "r2" "r3" places so that I could tune in for the best performance.Now I calculated the resistance set on those potentiometers and made a new design with all the same just usual resistors in those places and the circuit didn't function at all even changing values was no luck.