Microprocessor control of DC motor drives

A microprocessor-based control system for a DC motor, which uses standard hardware, is described. The theory of regenerative braking is used to develop a control system for DC drives which is based on the operation of a four-quadrant switching circuit. The system was designed with a new integrated circuit which contains a four-quadrant switching circuit and onboard control logic. The motor will force current back to the supply, which will reduce the speed of the motor. The system program contains a variable braking delay to ensure the slowing of the motor to a speed level that will not produce high surge currents during reversal. The system has many industrial and commercial applications and can be modified to conform to specific voltage, current and horsepower ratings. Applications of this system range from larger industrial drives to small DC drives and servo-motors such as those used in robotics, printers, and plotters. The system microprocessor can also be interfaced to other control units for process control applications.<>