It will always rotate in the same direction. It will run on square wave but hotter than normal and it will kickback into the drivers something terrific. It needs a full wave voltage to work (can't have dc through it although some motors can). This means transformer or H bridge or 1/2 H drive. The usual scheme is doubler rectifier from ac into two series capacitors and push-pull driver driving the motor between the pushpull output and the center point of the capacitors. As I have said, if the waveform is not sinus there will be major kickback issues. The starting current can be scary (depending on construction). You can always replace a synchronous motor with a stepper which is easier to drive (but won't do 3000 rpm easily). A stepper driven with 2-phase drive and a better driver IC will likely outperform the synchronous motor in all respects except cost and weight. Peter -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads