Non-FRC Motor Controller?

[Al Skierkiewicz]

OK,
Here goes...
The Red Spike which has not been sold for quite a while (+12 years) had a small limitation in that while it could reverse polarity to the output (M+ and M-) it could not independently switch from positive voltage to common. (It could make both outputs common) The Blue does allow that and so it has four states, one is both outputs high (+v), one is both outputs low (common), one where one output is high and one is low or one where the last condition is reversed. Spikes have never been solid state. In the strict definition of an "H" bridge i.e. four independent switches, the Spike meets that definition. It is simply two single pole, double throw relays, with the common terminal of each connected to the M+ and M- outputs.
The nature of the self resetting breakers used in FRC allow a 600% over current rating for up to 2 seconds before trip when at ambient temperature. That is 240 amps for the 40 amp breaker. It is likely that you will not experience a trip even at 45 amps. The CIM motor is rated at 133 amps in stall, and free speed current of almost 3 amps.
While you would think that software might be able to pulse the relay, in reality, the time it takes to move the contacts might make this a frustrating experience. When used with higher current motors, those above the rated 20 amps, significant arcing of the relay contacts will result from the inductive loading of a motor switched at a frequency needed to control motor speed. Used in this operation, the resulting degradation of the contacts may even fuse the contacts in some cases, rendering the relay permanently in one state.
Please note that while a single solid state relay is capable of switching the current to the motor, it is not capable of reversing the motor. An "H" bridge could be constructed using four such solid state relays. The cost of the four devices and drivers would approach the cost of a Victor or Jag. However one needs to be careful to use SSR designed for switching DC loads and rated currents. Please note that the IFI SSR linked above is rated for 7 amps.