I'd like to drive a standard DC motor (Perm or Etek) with a controller that can't tolerate CEMF. I'm thinking I can solve the problem by putting a freewheel, or snubber, diode across the outputs of the MOSFETs. I haven't measured the back EMF of these motors, but I typically see regen currents of up to 50 amps max. So I have two questions:
How best to measure CEMF? I do have access to some test bikes. Will I see the CEMF using a non-regen controller like the Alltrax? I admit to some laziness here - I should measure first, ask questions later.
What parameters should I look for in the diode? Clearly voltage and current capabilties - anything else? Switching times? I don't think heat dissipation will be much of an issue, as regen doesn't happen for very long. I suppose coming down a long steep hill might be a problem, and I should plan for that.