----- Original Message ----- From: "Rod Hower" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, October 01, 2002 9:13 AM Subject: RE: SepEx Motors and Controllers for EVs
> I've read about the advantages of sep-ex and don't really understand why > higher voltage systems aren't available. Would it be possible to have > Warfield or NetGain rewind a series motor for high voltage sep-ex? > Wouldn't building a high voltage sep-ex controller from scratch be much > easier than a similar voltage series controller? Things are a bit more complicated than that. A sepex motor needs interpoles so just rewinding a series motor wouldn't do the job except of course for a motor like a Kostov which has interpoles already. A good sepex controller is much more complicated than a series motor controller, not simpler. It needs a section similar to the series motor controller to control the sepex motor's armature current. Another section is needed for the sepex motor's field current. The field conrol section should provide high field current for good starting torque and for regeneration, weakening the field current for high speeds, and reversal of the field current to reverse the motor. It also needs to be programmable to allow setting it up for each application and user's preferences. A good example of a sepex controller is the Curtis model 1274 described at: http://www.curtisinst.com/Uploads/DataSheets/ACFEFE5.pdf A higher voltage, higher current version of the 1274 and a compatible motor could be a great sepex setup for EVs. A feature of any good sepex controller that distiguishes it from a simple series motor controller is programmability. My Curtis 1231C has three adjustment pots which I've never touched. A sepex controller needs adjustments to set up field control, regeneration, speed control, etc. The Curtis 1274 and other sepex controllers connect to a seperate handheld programmer module or to a computer to set up the controller to suit the application and the user's preferences. Tom Shay
