Background: I am considering a project to use a treadmill motor to run a table lift mechanism - heavy work table that will hang by one edge when stored. The motor is permanent magnet dc motor with brushes, rated at 130 vdc, 21 amps. I have run the motor on the bench with the original MC-60 motor controller, using 5K pot to control speed. The controller uses PWM to drive the motor.
The motor would be run at the lowest possible speed, and only momentarily while it raises/lowers the mechanism 15 inches.
Question: I wanted to use Arduino-controlled relays to control direction of the motor. Start, stop and speed could be done with the pot or switched resistors, I'm sure and I think I could manage that. But for direction, I was thinking of reversing the motor wires thru a relay shield. But, it seems the heftiest shields I can find are rated AC250V 10A ; DC30V 10A. Maybe that's sufficient when I find out what the equivalent voltage and current draw is at the low speed I plan to use. But, I'm not clear on that - anyone know how they would go about controlling higher DC voltage/current?
PS - I am aways from actually being able to work on this, so I probably won't be able to pursue an active dialogue here for a while. I'm still collecting my thoughts.
Thanks for any ideas.