How to calculate correct voltage for stepper driver ?

How do I calculate the correct voltage for my stepper drivers ? I have had a look at the wiki but I don't understand(I am not good with numbers) is it amps x inductance = voltage ?

Thanks Nikki

If you have "r100" shunt resistors on your driver ( most common) you can skip the math and say 0.4V equals 0.4 A
-Olaf

Thanks looking at one of my spare driver boards the r1 says 303 ?

Thanks Nikki

Not R1,
it´s one of the resistors marked on my picture ( red or blue box )
-Olaf

Thank You there are r100 ill get tweaking !

thanks Nikki

Quote
Nikki81
How do I calculate the correct voltage for my stepper drivers ? I have had a look at the wiki but I don't understand(I am not good with numbers) is it amps x inductance = voltage ?

Thanks Nikki

Nikki,

Close, right stadium, wrong seat.

For DC, it's Volts = Ohms * Amps. For AC, it gets a tad more complicated but boils down to Volts = Impedance * Amps. Impedance is a function of the frequency applied working against inductance, capacitance, or a combination of the two. When in full step mode, it is just pure DC with the stepper in current limit.

The resistor that is being spoke of is the current sense resistor that the stepper driver uses to monitor the amount of current going out to the stepper. It can be any value but it needs to be known to set the reference voltage for the stepper correctly. The supplier of the modules should be able to tell you what the value is or you will have to measure it. In the case of my Pololu DRV8825's, the reference voltage is 0.5 volts for 1 amp current limit. On this board, all I had to do was put one lead of my meter to ground and the other on the shaft of the screwdriver to make contact with the wiper and just adjusted for 0.5 volts. Did that and walked away from it.