We are Driving stepper motor of Sanyo Denky make,Bipolar ,2 Amp/phase rating(40Kg-cm).The schmetic for the same is available at http://www.8052.com/users/archana.

We are facing a problem while driving this motor at particular speed .If we gradually (linearly) increase the steppings of motor from 50 steps/sec. to 150 steps/sec. we have observed that the motor loses Torque at particular range of speed of 60steps/sec to 70steps/sec. and above this speed it again becomes normal till range of 120steps/sec to 130steps/sec. after which it again becomes normal.

We suspect the effect of resonance either from electronic side or from mechanical side. Please suggest some possible reasons.


Anju Vaghasia.