FWIW, at the meeting last night I discussed the switching FETs slated for the new gizmocopter PWM motor drivers. They use a case which is somewhat like the TO-220, but a bit larger (TO-247). Here's a link to the package spec:
http://www.irf.com/package/hexfet/to247.pdf <http://www.irf.com/package/hexfet/to247.pdf> The datasheet for the transistor is here: http://www.irf.com/product-info/datasheets/data/irfp054.pdf <http://www.irf.com/product-info/datasheets/data/irfp054.pdf> The snubber diode I'm considering is here: http://www.irf.com/product-info/datasheets/data/hfa30pb120.pdf <http://www.irf.com/product-info/datasheets/data/hfa30pb120.pdf> I believe if we attach one set of these components (one FET and one diode) to each arm of gizmocopter -- directly under each propeller, then cooling won't be a problem. The FETs can drive up to 70 Amps continuously, but I can't imagine we're going to even get close to those conditions. The diodes are rated for just 30 Amps continuous, but 90 Amps repetitively pulsed, so I believe they'll do alright in their roll as snubbers. I may want to reconsider these particular diodes as their reverse breakdown voltage is much much higher than would occur in our 12 VDC system. _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
