How many Amps does 1 FET give? 5A? Will 18FETs give 90Amps?
More FETs in a controller usually gives a more robust and cooler running controller...
GM's controllers have 6 FETs; 3 for handling motoring, and 3 for handling regen. (one for each phase)
The FETs used are P140NF75, which can handle max 75V, and max 120A continous
each with proper cooling.
If the controller had 2 FETs in parallel for each phase, it would still handle max 75V, but could handle max 240A for each phase, and would then run cooler for the same power run through. (now, the gm magic controllers (so far), handles only around 60V max, due to some capacitors at the voltage input.
)
All this said; the GM controllers are, by the firmware, limited to max 30A continous, 50A peak. This to protect said FETs, and of course, to avoid overheating and burnout of the GM motors which the controllers are designed for.
I am not familiar with other controllers, like the Infineon, but I'm sure if they're properly configured for the motors one use them on, they'll perform just as good as, if not better than GM's...
