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Stepper Fundamentals Slide 22

Using the chopper controlled current drive to drive the stepper motor provides a very fast current rise and good efficiency in the circuit. Comparing the current waveform to the previous example, there is a slight improvement in the rise time compared to the L over nR configuration. This example shows the same motor from earlier operating at 5 times the rated voltage (25V) with a chopper current control set to control a peak current of 1A. There are a lot of advantages to using the chopper drive that improve the performance and give a very good efficiency. The disadvantages of complexity and additional circuitry have mostly been overcome by integrated motor drivers that include all of the control circuitry and, in many cases, also the power transistors on a single monolithic IC. Although some low end applications are still designed using a simple L over R drive and a unipolar motor, most applications today use a chopper drive with integrated driver ICs to drive bipolar stepper motors.

PTM Published on: 2011-12-14