ben said:
I have a golf cart charging transformer with two 45 V output coils. I
need 30 to 40 Volts DC at ~ 20A to run stepper motors. Can anyone help?
TIA, Ben
Hi, Ben. The easiest solution for a "tinkerer" would be to use a
rectifier and filter capacitor to get around 60VDC, then use a
resistive current limiter to keep the coil current to spec.
L-R drive has the advantage of getting somewhat more torque at higher
speeds, at the obvious cost of wasting a lot of power through heat.
See Jones on Steppers:
http://www.cs.uiowa.edu/~jones/step/
particularly Section 4: Current Limiting for more information on this
and other methods to accomplish what you want. See particularly Fig.
4.1a. -- suitable for lower speed operation.
If you're looking for an inexpensive source of surplus power resistors,
you could do worse than Surplus Sales of Nebraska.
http://www.surplussales.com
Be careful, and don't forget the diodes!
Good luck
Chris