| 摘要 |
PURPOSE:To extend a time when service is possible, by lowering the transmission output to reduce current consumption according as the voltage of a battery is lowered. CONSTITUTION:When the voltage of a battery 0 is a normal value, a voltage control circuit 8 is turned on, and the output of a trasmitter 10 becomes a normal prescribed value. Next, when the voltage of the battery is lowered to become a reference voltage or less of a reference voltage generating circuit 2, the output of a comparator 3 is inverted, and a switching circuit 9 lowers the transmission output of the transmitter 10. Next, when the voltage of the battery is lowered furthermore to become a reference voltage or less of the second reference voltage generating circuit 6, the output of a comparator 7 is inverted to release the output of the circuit 8. Consequently, the battery 0 is disconnected from a load circuit, and thus, overdischarge of the battery is prevented. |
