View Full Version : Stepper current rating

10-27-2006, 09:00 AM
Okay maybe this is a stupid question...

But i just wondered, does the maximum allowed current in unipolar mode double that in bipolar mode?

eg. unipolar stepper 12 volts rated, 10 ohm coil resistance (A-B) so 5 ohm resistance in common-A/B.

The maximum current will be in unipolar mode ie 12/5=2.4 amps (these are arbit values) that can flow through the coil.

In bipolar mode, 12/10=1.2 amps. But since we have 2.4amps flowing in the unipolar mode cant we double the voltage in bipolar and have the same (24/10=2.4amps) in bipolar?

Maybe it depends on whether the steppers are rated for maximum voltage or current through them. If its voltage(it is i think) why is it so? cause max current seems more logical to me (ref. overvolting-chopping). So can someone explain what decides the maximum electrical rating for it.
Thank you!