Hi all,
I'm trying to build a variable DC power supply, 0-110V 5A. At the moment I use a 6A variac and 240:110 isolation transformer, this is ok but very bulky and there's no current limiting. I don't have any experience with SMPS but I figure this is the way to go, is it?
For a first attempt I built a half bridge converter and wound a small transformer (10 turn primary, 10 turn secondary, AL 145nH). Switching at 150kHz the rectified output into a 50ohm load looked promising. Am I right in thinking that in such a configuration a variable voltage is achieved by varying the duty cycle at a fixed frequency?
After testing the half bridge with my labs DC power supply (70V, drawing