| 摘要 |
PROBLEM TO BE SOLVED: To provide an automobile clock capable of preventing the deterioration of display quality by preventing the change in luminance of a display caused by a reduction of power supply voltage. SOLUTION: A switching circuit 14 connects a power source to a clock circuit 2 through a Zener diode Z2 when the power source voltage is higher than a fixed voltage, and connects the power source to the clock circuit 2 through a booster circuit 16 and the Zener diode Z2 . A charge part power source circuit 18 supplies power for charging and boosting. A charge circuit 20 output a voltage boosted by repeating charging and boosting in response to the signal from an oscillating circuit 22. Accordingly, a prescribed voltage can be regularly supplied to the clock circuit 2, and the change in luminance of the display can be prevented. |
