# Stepper Motor voltage allowable?

Discussion in 'Sensors and Actuators' started by eem2am, Aug 14, 2010.

1. ### eem2am

414
0
Aug 3, 2009
I have this stepper motor which i intend to drive with 36V even though its only 6V rated................

("UBB1", Rated Voltage = 6V, 18.5Ohms per phase)

....how can you tell what is the maximum allowable drive voltage for this (above) stepper motor...or indeed, for any stepper motor?

2. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,482
2,830
Jan 21, 2010
You're making a smoke machine, right?

In this case it says 6V.

The only way you might get away with 36V is to use PWM with a max "on" time of around 15%. Even then, I'm not sure it would be my fiirst choice.

3. ### Resqueline

2,848
2
Jul 31, 2009
For static purposes a voltage rating is fine, but for dynamic high-speed use one should consider using the current rating instead.
A stepper has a considerable inductance and so it takes a while for the current to rise after a voltage step. It is the current that drives the motor to a new position.
So to make the motor run real fast one needs to use a higher voltage than rated power supply and drive the motor with a constant current instead.
Using a (constant current) PWM scheme will be neccessary to avoid having a large power dissipation in the driver.
One may also need to know if the rating is for full-step use only or if it can take half-stepping too (which increases the average motor dissipation by 50%).