Does anybody know if Roman still around? I tried to email him with a question about his 2 Trans SMPS but I haven't heard back from him. I built his basic SMPS circuit and I'm seeing some behavior that I cannot explain. It basically works but it is only switching in repetitive bursts. The period of the bursts varies with the size of the output filter capacitor. I have some scope screen shots that clearly show what is going on. I'd appreciate it if there is anybody on the list that has played with Roman's circuit or SMPSs in general who would be willing to take a quick look at my scope shots offlist and tell me what they think is going on. Please email me if you are interested. Thank you. Mark Peterson markjonnet@hotmail.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist