| 摘要 |
<p>A circuit for control of the speed of an electric motor, particularly a shaded pole motor, in accordance with a control voltage includes a ramp generator (1) for generation of a sawtooth voltage, a comparison voltage (4) with two inputs which are supplied with the control voltage and the sawtooth voltage, respectively, a trigger circuit (5) whose input is connected to the output of the comparison circuit (4), and a triac (6) which is connected in series with the electric motor (7), the control electrode of said electric motor being connected with the trigger circuit. The output of the comparison circuit is connected to a control input on the ramp generator (1) which is arranged to give a steep ramp when the comparison circuit is OFF and a slightly less inclined ramp when the comparison circuit is ON. The circuit can thus also control e.g. motors with a greatly varying torque.</p> |
