| 摘要 |
PURPOSE: To provide a power circuit, in which power consumption caused by charging resistor is reduced in a buttery mounting state, while a malfunction caused by a leak current in a transistor is eliminated when a buttery is not mounted. CONSTITUTION: A voltage from an AC adapter is fed through a resistor R5 to the base of a transistor Q2 when a battery is not mounted. Then, the transistor Q2 turns on. A leak current of a transistor Q3 is discharged through a discharging resistor R1 and the transistor Q2. When the battery is not mounted, the transistor Q1 turns on and the base of the transistor Q2 becomes a low level, and then the transistor Q2 turns on. At this time, the discharging of the battery is stopped. |
