Hi, I tried to simulate the 2 transistor circuit Roman published to the list a while ago and I was not able to make it oscilate under switchCad spice simulator ! Is there any tricks the can be made to make it work in simulation ? I am absolutely sure it works in practice :-) By the way, everyone should download the software from linear tech site. It works as a charm and is much easier to use than other "spices". Best regards, Alexandre Guimaraes -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads