| 摘要 |
PROBLEM TO BE SOLVED: To provide a revolution control circuit which is composed of small size and light weight components only and by which the revolution of a motor can be increased or decreased toward a predetermined revolution. SOLUTION: A revolution control circuit changes the charging current of a capacitor 5 and performs the phase control of not only a bidirectional trigger diode 4 but also a TRIAC 3. The AC terminal of a single-phase full-bridge circuit device 61 is connected to a point between one end of an AC power supply 1 and the capacitor 5. A series circuit of a filter capacitor 9 and a diode 8 is inserted between the negative side DC terminal N of the single-phase full- bridge circuit device 61. A P-N-P transistor 7 is inserted between the negative and positive DC terminals N and P of the single-phase full-bridge circuit device 61. A series circuit of a time limiter charging resistor 11 and a time limiter charging capacitor 13 is connected in parallel to the filter capacitor 9 and the connection point between the resistor 11 and the capacitor 13 is connected to the base of the P-N-P transistor 7 through a resistor 12. |
