Re: [CAD_CAM_EDM_DRO] Stepper Voltage and Current question

Bob Stone wrote:

> Hi,
>
> If the motors are 3 volts and 2 amps, that means the windings are 1.5 ohms.
> If you apply 25 volts to these coils you'll draw almost 17 amps which will
> shut down your supply, toast your driver circuit, etc.
>
> To limit current, say at 25 volts, you'd need a approx. an 11 ohm power
> resistor that could handle 110 watts. That would be nuts. You better have a
> chopper drive

Right. Nobody in their right mind builds unipolar drives unless they want to
prove how poorly they perform!

> and even then I'd go to a higher voltage motor with that
> supply.

No, the motor is a good choice. Even lower voltages are better as they have
lower inductance. But, running that motor with a 40 - 50 V power supply will
give better performance in the top speed range.

Jon