Electrical – How to measure Stepper motor current when using EasyDriver A3967

stepper motor

We are using EasyDriver stepper motor driver A3967 for running a stepper motor. We wanted to measure the current consumed by the motor using an oscilloscope. Can you give us some suggestions on how can we do that? I read about measuring the voltage across the sense register but I don't know whether it is the correct way? Where can we add a resistor in the circuit to measure current consumed by the motor?

Best Answer

You can measure right across R1 and R2 to get the current in each phase. Since they are 0.75 you must divide the voltage by 0.75.

With resistances this low, a good practice is to put a scope probe on either side of the sense resistor and use the math function (A-B) to subtract the traces.