| 摘要 |
PURPOSE:To realize a battery life detector with simple constitution in an electronic watch provided with a radio receiving function wherein two kinds of electric power supply parts for a radio receiver and for a watch are provided, by checking the power supply for the radio receiver at all times by utilizing a battery for the watch and a display device. CONSTITUTION:The electric power supply for a radio receiving circuit 1 is a battery of a voltage ER and operates when a switch SW is closed. The voltage ER is divided by resistances R1 and R2 and the voltage E0 thereof is inputted to an inverter circuit constituted of transistors Tr2 and Tr3. The output thereof is connected to a latching circuit 2 which holds the information thereof. This information controls the gate of an AND circuit 3. A 32Hz clock is supplied from B to the other input of the circuit 3, and when the voltage ER drops below a constant value, the BAT segments of a liquid crystal display device 6 of a watch circuit 5 are lighted. |
