| 摘要 |
PURPOSE: To prevent long term discharge of a battery by ensuring an appropriate operation of a controller during a short or intermediate term interruption of a power supply from the main power supply and disconnecting the battery from the circuit during a long term interruption of the power supply. CONSTITUTION: The electronic controller comprises a circuit 12 for connecting a main power supply detection circuit 11 and a battery 13 with a circuit, and a logic processor 14. When the voltage of a main power supply drops below a predetermined level, the logic processor 14 is operated through the main power supply detection circuit 11, the battery 13 is discharged through a transistor and down counting is performed by means of a counter 19. The battery 13 is discharged continuously during count down and disconnected from the circuit when the main power supply is recovered. When the main power supply is not recovered upon finishing count down, the battery 13 is disconnected from the circuit. According to the arrangement, the battery can be prevented from being discharged for a long term. |
