Re: [PSUBS-MAILIST] Re: Motor controller...

[Subscuba@aol.com]

John,

I have been looking at your application for the motor controller. Although I 
haven't drawn a schematic, I suggest we use a Unitrode UC2637 Motor 
controller (try www.Unitrode.com, look at application note U-102) and four 
IXYS IXFX 150N150 (www.ixys.com). These are 150 volt devices with a thermal 
impedance of 0.22 Degrees C per watt and have a 150 ampere rating. I didn't 
check on the cost but you might.

I'll be working on the schematic this week. It looks like it will be simpler 
than my controller and yet be an H bridge which you can use for all your 
motors. Your pot in the joystick would probably be a linear taper 1K pot. The 
real problem will be in packaging the electronics such that parasitic 
inductance's will be minimized. We will still need some very high quality 
capacitors to act as local bypass to avoid voltage spikes. Short leads to 
your batteries will help. Motor lead lengths are not important. The controls 
can be located anywhere you wish but the power controller needs to be located 
close to your batteries. Have you given any thought to fuses and contactors 
(solenoids) to apply power?

Ken Martindale