Control circuit for linearly controlling the speed and direction of an AC powered DC motor in accordance with the magnitude and polarity of a DC reference signal

摘要

A control circuit for use in controlling both the speed and direction of an AC energized DC motor in a linear relationship to the magnitude and polarity of a DC reference signal. This is accomplished with a triggerable bidirectional current conducting device, such as a triac, which is connected in series with a DC motor across an AC power supply source. A control circuit serves to trigger the bidirectional current conducting device into conduction at a selected firing angle during the positive or negative half cycle of the AC source in such a way that the firing angle is linearly related to the magnitude and polarity of a DC reference signal.