Measure current going to biploar stepper?

Forum 2005-2010 (read only) Hardware Interfacing
1

Anyone able to tell me how I could measure the current (amps/milliamps) going to a stepper?

I wired up from my previous post , everything is great but the stepper is rated for 600mA PEAK and my driver has a pot that goes from .25A -> 2.5A ... I felt it getting mighty hot and pulled it almost all the way down but would like to set it under PEAK and mark the pot so it doesnt get fried :slight_smile:

its a 4 wire m42sp-13nk running at 12V and < 600Ma I hope!

Thnx

2

Hi,

you need a shunt (0.1 Ohm or so) and an oscilloscope to measure the current. The amplitude of the square wave you can see on the oscilloscope in Volt divided by the shunt resistance in Ohm is the current.

Mike

3

Mike_Pa,

I was afraid you were going to say that LOL No shunt nor scope here LOL Could I read the resistance of the pot and multiply across the drivers rated .25 -> 2.5A for a ballpark?

4

I suspect it has more to do with the wattage rating of the potentiometer. Even at the minimum current you need a potentiometer with a 3 watt power dissipation rating. Get a 5 watt pot and try it again.