What's the story of small NEMA 23-ish sized reluctance motors like this?
I've got a similar "20R-17A" series one from Rapidsyn, with a 1986 date code. It has 5 leads, has no cogging feel to it, and if you energize a winding, it loosely feels like it has 6 steps per turn. Considering there's no magnets and the inertial is virtually nothing, it has to be a reluctance motor.
I've never found a databook or even spec sheet from any of these small reluctance motors. Can it be driven with sequential steps if I can figure out the phasing or is quadrature driving the norm? Were these things designed for speed?
Reluctance motors seem to be the rage again for getting another 1% of efficiency over plain induction motors for industrial uses now, but there's about zero info on these smaller stepper sized motors.
Anybody ever use these things or know why they even exist?