Hi all,

As my workshop and office are all in storage, not that i could get to them in my wheelchair anyway, i need someone to carry out a little experiment for me. i'll explain why in a later post if the results are useful....

kit needed:
a stepper motor, any sort but lets say a nema23 bipolar for now
some way to turn the shaft at a regular but lowish speed up to 100rpm
a dc power supply with adjustable current limit up to the stepper current rating
an oscilloscope

Basically i want to spin the motor at various speeds while applying a controlled DC current to one phase winding and seeing what gets generated at the other phase.

My expectation is that the motor will get harder to turn as the current is increased and the other winding will generate a sinusoidal voltage, the amplitude at a given speed will have some relationship to the effort needed....