Synchronous motor drive with chopper regulator

摘要

In the disclosed system, a switching circuit energized from a source applies current pulses to the windings of a motor, such as a stepping motor. A chopper regulates the winding currents during each current pulse through four or more control cycles, a power cycle, a circulating cycle, a reset cycle and a second circulating cycle. The chopper enables current from the source to the winding during the power cycle; disables the source and forces residual current entirely within the switching circuit and outside the source during the circulating cycles; and constrains current flow from the winding through the source against the plurality of the source during the reset cycle. Preferably, a second switching circuit energizes a second winding and the chopper times the cycles so that the power cycle in one winding coincides with the reset cycle in the other winding.