I am no expert in EE but, I ever came across a method of converting AC to DC using just capacitors ! I think it is called as, full-wave rectifer. The capacitor I came across is quite large (about the size of an eraser) and looks like it is made of ceramic/ plastic. Perhaps, you can visit this web address to see is this what you want; http://teachers.web.cern.ch/teachers/archiv/HST2002/smallexp/Vogt/diode.htm roines reenig wrote: Hi, I was just looking at this board that is intended to allow for remote control of a mains load. Meaning, let's say you've got a lamp. It's got just one wire coming in and one wire going out. That's the live-wire in, and live-wire out and in-between, you (the lamp in this case) are the load. This board goes in between the live-wire in and the lamp. This board appears to have some sort of processor, looks like a samsung 8 bit processor, some eeprom and some digital IO. I didn't get a chance to examine the board any further before it was taken away from me. Now, it's powering itself from the mains live-wire in and I presume grounding itself using the live-wire out, therefore increasing the leakage current. I assume that it's not leaking so much that a flourescent lamp would start to flicker. Any ideas how this power supply mechanism works? The CPU's very likely to be a 5Volt part, so they must be able to generate the 5 volt DC voltage and current from the mains. I realize that there are high voltage switching power regulators like the VB409 that could generate 80mA and regulated 5Volt from mains. Is that what they are likely to be using? Or do they have some special stuff since they don't have access to ground and neutral wires. Thanks, Roines --------------------------------- Do you Yahoo!? Friends. Fun. Try the all-new Yahoo! Messenger -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads --------------------------------- Do you Yahoo!? Friends. Fun. Try the all-new Yahoo! Messenger -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads