# Thread: Please confirm my stepper voltage calculation?

1. ## Please confirm my stepper voltage calculation?

Could someone please verify that I have the calculations of voltage right for this motor that I bought?

It is a RS34-600oz stepper...2 phase

I am running it in Parallel from a Gecko 203V

The table below shows that the inductance of the motor in a parallel config is 1.2.
I have calculated (1.2 sqrt) X 32 = 35.05
So I bought a power pack that puts out 30 Volts and will supply 7 AMPS
The reason I ask, is that the company I bought the stepper from is telling me to run it at 50-60volts ( I think they are quoting the voltage for a series config.)

Am I correct with 30 - 35 volts in a parallel config, or am I wrong?

SERIES 3.7 V 3.5 A/phase inductance 4.8 +/- 20% mH/phase

PARALLEL 1.82 V 7.0 A/phase inductance 1.2 +/- 20% mH/phase

UNIPOLAR 2.6 V 5.0 A/phase inductance 1.2 +/- 20% mH/phase

Cheers
sco

2. You can run these steppers at 65-72volts no problem. I run my RS34-1200's at 65 and they run great.
It is important though not to run them at more than rated current. The 203V's are capped at 7.0 amps anyway, so you'll be fine.

Timothy

3. Really!?!?
I do believe you, but how does that work with the 'gecko equasion'?
sqrt X inductance X 32.
Does that equasion calculate per phase and because there are 2 phases, you multiply the result by 2?

cheers
rosco

4. I asked the same questions when I first bought my stepper motors for my retro fit project. This is the reply I received;

"The 20X rule has been thoroughly debunked by now even though certain individuals still put it forward. It's based on an equation that doesn't take a number of important fact into account. I've been selling the 1200's for over four years and was advised back then by a good mentor to apply 65-70 volts with a G201 for the best upper speed torque. 54V is no problem and don't forget that stepper are made to be run hot, unlike servos."

So I bought a 65volt power supply and everything is working fine.

Timothy