As for a source of fets to blow up, I've taken apart dozens of old PC power supplies. Quite often they just have bad fans. A local used computer store had a 'take it all away' sale, giving away all their old inventory (only really good for parts), and I got about 30 power supplies. But it looks like due to the generous offers from people on this list you will not have to go this route.
What you describe is very similar to what I made. I use mine for testing smaller amp-hour LiIon batteries, so it's smaller than what you need. I used some building blocks from here: http://www.geocities.com/hagtronics/load.html 0-100V, 0-10A, 150W total. Small, battery powered, and can be scaled for higher power. Can get most parts as 'samples'. I have a few extra PCBs. http://www.geocities.com/hagtronics/pic_das/index.html Simple pic based data acq. system. Serial port on one end, 8 ch. 12 bit A/D, 4 ch 12 Bit D/A, 8 ttl I/O. I've had problems with the FETs blowing, so I think I'm going to use the $100 LabJack, USB Based. But for the above, PCB is about $7.00 IIRC, and once again can get most parts as 'samples'. If you don't have to pay for it, LabVIEW is great for data acq. tasks. $2k is a bit much for a hobbiest, though. Our LabVIEW Rep. said that the licence allows you to use a copy at home. Not sure why most people would want to do this, but it works out great in my case. - Steven Ciciora Mason wrote: I'm building a battery load tester for a school design project and I'm looking for an IGBT or MOSFET to modulate the load. I was curious if anyone had one sitting around (maybe from a blown controller?) that you wouldn't mind getting rid of. I'm aiming for a maximum continuous current of 50 amps, so something with a rating higher than that would be great. The bigger the better... then I don't have to worry (as much) about heatsinking and venting. ;) For those that are interested, this is going to be a pretty nice device! My team is using LabVIEW to monitor and control our unit. It will work with a "typical" automatic battery charger and allow the user to select the desired discharge rate and load test cutoff voltage. Our device will then activate the external charger, recognize when the charger is done, deactivate the charger and perform the load test, then re-activate the charger and report the results of the load test. A nice, automated device for testing EV batteries... and not too bad of a senior design project either! Anyway, if anyone has an available transistor that meets the criteria, name your price and feel free to email me offlist. Thanks! mason
