The driving circuits adopt constant current chopping for the purpose of improving rotating torque and increasing working efficiency of the stepper motor.

This paper proposes an energy saving control mode for current source inverter(CSI) induction motor drive system with the motor driving a constant power load.

The trigger PCB consists of two parts, first (upper half of the schematic) the trigger and constant-current LED drive and second (lower half) the PWM motor current controller.