摘要 |
A pulse width modulated DC motor control system is designed to operate a DC motor at constant velocity. Feedback pulses generated at a rate proportional to the rotational velocity of the motor are converted to control pulses having a fixed on-time period which is independent of changes in the velocity of the motor. The control pulses are used to modulate a constant current source whose output is integrated to generate a sawtooth voltage signal whose average DC value is used as the basis of or pulse width modulating a DC voltage applied to the motor drive circuits of a DC motor. |