Modeling motor control

[Kevin Sevcik]

They very well may have changed it for the FRC firmware. Again with my caveats that this is all based off the reference source code released by Luminary Micro, which may not be identical to the FRC firmware. I'm not much interested in hunting up a disassembler for pick apart the FRC firmware just to double check things though. Anyways, the only reason I can think of for not doing it is if the don't trust the dead time protection in their FET drivers.

FETs all have some delay between turning off the gate supply and when conduction actually stops. So if you're simply turning off the high side and turning on the low side at the same instant, you can get "shoot-through" where you've actually shorted V+ to V- for some small amount of time. This is obviously bad, so most integrated FET drivers have provisions for adding "dead time" between turning one side off and the other on. The Tan Jag's driver says it has built in dead time, but Luminary Micro may not have trusted it, or may have discovered a problem with their implementation of it. Or they may have just not wanted bother with the possibility of a problem.