Driving the step motor with controlled phase currents

This work presents a study of the method of electronic subdivision of the step angle for stepping motors. The method is based on the control of the phase currents, and allows for the accurate subdivision of the motor's natural step angle. It is particularly interesting for applications where the required step resolutions are smaller than that offered by the motor. The main advantages are the elimination of mechanical reducers, the possibility to achieve any substep size, no increase in drive volume and no increase in cost as only small alterations in the electronic circuitry are required as compared to conventional driving. Substep sizes are programmable via software. It is described the methodology, simulation program and the electronic converter built in the lab. Experimental and simulated results are shown, compared and find to be quite good.