| 摘要 |
PURPOSE:To stably control the rotating speed by triggering the gate of a thyristor by the difference between the voltage of a capacitor charged by the voltage applied across a thyristor and the prescribed voltage. CONSTITUTION:The output of an AC power source 11 is supplied through a full-wave rectifire 12 and a thyristor 14 to a motor 13. The voltage across the thyristor 14 is charged to a capacitor 17, and a comparator 20 starts charging a capacitor 22 when the voltage of the capacitor 17 becomes the prescribed value. A comparator 25 applies a trigger signal to a thyristor 54 when the voltage of the capacitor 22 becomes the prescribed value or higher. When the thyristor 14 is turned ON, the charge of the capacitor 17 is discharged through a diode 29. |
