An easy way to remember the distinction between unipolar and bipolar is that in a UNIpolar coil the APPLIED current is always in ONE direction. UNI-POLAR. In a bipolar coil the APPLIED current may be in either of TWO directions. BI-POLAR. Bipolar coils are almost always driven with H Bridges. Fr. Tom McGahee ---------- > From: Wagner Lipnharski > To: PICLIST@MITVMA.MIT.EDU > Subject: Re: [OT] Driving a Stepper > Date: Thursday, August 19, 1999 12:31 AM > > Unipolar, Bipolar, arggggg, after so many people doing sex change, it is > starting to make people confuse when you make a fast question "What > would you think if you find that your best friend is heterosexual?"... > some people just keep thinking... :) You are 100% right, I crossed > names. > Wagner.