| 摘要 |
A DC motor speed control circuit in which the current to the motor is delivered in a series of pulses the width of which is variable in accordance with the setting on a throttle control potentiometer. The pulses are shaped to provide a fast turn on and slow turn off of the control transistor to avoid heat build up and lessen the inductive kickback of the motor. A novel feedback circuit senses excessive current draw and automatically shuts down the circuit and remains latched in that condition until the throttle control potentiometer is reduced to zero whereupon the circuit automatically resets itself. High efficiency is achieved by directing both the power current and the control current through the motor windings thus increasing the battery life.
|
