I"ve tried this with an induction motor connected to the mains, and driven by a gas motor (don't tell my power company). We could rev up the motor and watch the power meter run backwards when we were leading, it'd try to start the gas motor when we were lagging. Induction motors make neat connections to the mains - they will NOT produce power on their own without some exitation from the mains power. We tried this as well, getting the motor up to speed and running the power meter backwards, then suddenly disconnecting it. Voltage at the motor leads would quickly drop to zero even when driven by the gas motor. How this works I wish someone would explain. If you want a simple, and not inefficient, mains-synching solar system, a 12VDC motor running an induction motor might be simple enough! Total mains isolation, automatic synchronization, lightning proof, and bonehead simple. Now - how to measure the power output of the motor, and use it to feedback to the 12V motor speed control? Gotta have a purpose for the PIC, y'know! Not so interesting to us engineers, who want to make it too complicated, with all these PWM switching circuits, but maybe a really practical method. Lawrence Lile ----- Original Message ----- From: "Jess Hancock" To: Sent: Thursday, March 08, 2001 1:52 PM Subject: Re: [EE] high efficiency feed to mains > Roman, What you want to do is similar to operating two ac generators > (alternators) in parallel to supply a load. If you want alternator #2 to > supply more power (watts), then its phase angle must lead that of alternator > #1. If you raise the voltage of alternator #2 you will supply more reactive > power (vars, not watts -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads