# Pololu A4983 Stepper Driver

Discussion in 'General Electronics Chat' started by Zapnologica, Oct 25, 2012.

1. ### Zapnologica Thread Starter Member

Jun 15, 2012
41
0
Good day,

I recently bought 3 * Pololu A4983 stepper drivers for a cnc i am building.

I am having some trouble with them:
http://www.pololu.com/catalog/product/1182

I have a 4v 1,3 A stepper.
But i see in the picture there it says that the motor volts are 8v-35v

Does this mean that it will not work with this stepper driver?

2. ### shortbus AAC Fanatic!

Sep 30, 2009
4,007
1,530
Stepper motors, to do useful work, are not driven at the nameplate voltage. The normal working voltage is much higher than the nameplate voltage, around 5 to 10 times higher.
The amperage is the important value, it should not be exceeded.

3. ### Zapnologica Thread Starter Member

Jun 15, 2012
41
0
so then i must measure the resistance of each coil?

and the work out what is the maximum volts i can give it for it to do 1.4A ?

4. ### Zapnologica Thread Starter Member

Jun 15, 2012
41
0
i measured now,

each coil is 3Ω ( with a multi-meter) and so if i run in bi-polar mode each coil will be 6Ω.

So then for me to get 1.4A

V = I .R 1.4 * 6 = 7.8

And so buy my calculations, i wont be able to power this stepper motor without exceeding the current rating ?

Sep 30, 2009
4,007
1,530
6. ### Zapnologica Thread Starter Member

Jun 15, 2012
41
0
Ok , i read it,
And it bases its whole calculation on Watts,

What if i don't know how many watts i want my stepper to do? (it says u have to calculate the weight of the dremmel etc) i just want to get the maximum drive out of the stepper? I am using small steppers for the machine,

Does that mean i must just drive them at their rated Amperage? and the voltage related to that?