| 摘要 |
PROBLEM TO BE SOLVED: To obtain a control circuit which elongates life and reduces the generation of inessential electromagnetic waves by a method wherein, whenever the supply of a voltage or a current to be applied to a DC motor is cut off, a polarity is inverted by a bridge circuit which is constituted of transistors or FETs. SOLUTION: When a main switch MSW is turned on, the FF 2 of a flip-flop IC is reset when an instantaneous current flows to a capacitor C2, and a voltage or a current is not supplied to a DC motor M from a bridge circuit composed of field-effect transistors FET 1 to FET 4 because gates A3, A4 of a gate IC are closed. When a power-supply cutoff switch BSW is turned off for a short while, the FF 1 of the flip-flop IC is inverted, the gates A3, A4 of the gate IC are opened, and the signal of the FF 1 of the flip-flop IC is sent out to a circuit at a next stage. A power supply is supplied from a storage-of- electricity circuit to gates A5, A6 of an inverter IC at the gate IC and to power- supply terminals of the FF 1 and the FF 2 of the flip-flop IC while the switch is turned off for a short while. |
