ECE577J

When we designed the schematic for nervous machine there was a concern of how to run 80 motors off of the logochip. The problem was that the logochip can't sync enough current to run them. So there are several options to switch power on and off with the logochip. NPNs and PNPs can sync enough current to supply 2-5 motors but not enough for what we wanted. N and P channel FETs are one of the other options. P channels allow about 1 Amp each and that would be enough but just barely so N channels are the best option because TO-220s will sync 14 Amps. The ones we ended up with will sync 9 Amps and that was plenty for each group. The reason the we blew up 16 FETs is because 90% of the motors were shorted.

Here is the FET datasheet for the small FETs that we used