A PROGRAMMED MICROPROCESSOR FOR A SPEED CONTROL SYSTEM FOR A D.C. MOTOR

摘要

System for controlling the speed of a motor receiving a feedback signal from the motor and sending a command voltage to the motor. It has been found that such systems, in the past, are often inaccurate and that speed drift can affect their performance. A system is provided for increasing the control accuracy of a motor (12) which feeds back a signal to a motor control circuit (14). The motor control circuit output (20) provides a command voltage to the motor winding. The motor control circuit (14) has an input (18) for receiving an input command from a source external of the motor (12). The actual speed of the motor shaft (26) is sensed and data representative of this actual speed is transmitted through a frequency to voltage converter (36) and an analog to digital converter (40) to a microprocessor (46) which calculates an input command based upon the received actual motor speed data. The input command is transmitted from the microprocessor (46) through a digital to analog converter (58) to the motor control circuit input (18). The command voltage from the output (20) of the motor circuit (14) is adjusted in response to variations in the input command transmitted from the microprocessor (46). This invention can be used to track and to control the speed of a DC motor.