Here's perhaps a strange question... I have a situation where I need both continuous rotation as well as incremental position control with hold capability. The approach that would work quite well would be to have a dual axis stepper motor between the AC motor and the load and have it disconnected (relays not just at the controller) while the AC motor is driving the load in a continuous fashion and then when I need to move it incrementally, turn off the AC motor, toggle the relays and use the stepper to do its thing... But I'm concerned that something would go badly after a while. The way I see it, if not powered, the stepper would just act as some kind of 4 phase generator, but considering that steppers usually run on low voltage & high currents, I am concerned that the voltages generated might be dangerously high or that the stepper is not designed for something like this.
Is it possible to drive a stepper motor like this for longer periods of time without damaging it? Anyone got any information about something like this? I was originally thinking of using a clutch, but the only way I could mount this is with the stepper between the AC motor and the load, not stepper behind AC motor. I would equally like to avoid gears if at all possible... The reason I cannot use the stepper in a continuous mode to drive the load is that I need a high HP motor for the continuous rotation and only a fairly low torque and low speed for the stepper part of the motion. I also don't think that I could use an encoder to then convert the AC motor to some kind of servo...
Anyone got some ideas on this?
Thanks in advance Joe