| 摘要 |
<p>PURPOSE:To prevent dead electric discharge, by providing a circuit for discriminating between service interruption in the course of operation and disconnection of an electric power supply due to an end of operation, and discharging a secondary battery only when the service interruption has occurred in the course of operation. CONSTITUTION:When service interruption occurs in the course of operation, a signal is still generated from an operating signal generating terminal PH of a microcomputer, a transistor Q3 in a discriminating circuit is conductive, but since a current passing through a resistance 13 and the transistor Q3 from a diode 14 is gone, the base potential of a transistor 11 drops, the transistor 11 becomes a conductive state, a current flows to a DC terminal D through a diode 10 and the transistor 11 from a secondary battery 8, and data in the microcomputer is held. On the other hand, when the operation ends, the operating signal from the PH is gone, therefore, the transistor Q3 becomes a cutoff state, the transistor 11 is cut off, and the current flowing to the microcomputer from the secondary battery 8 is gone.</p> |
