| 摘要 |
<p>PURPOSE:To prevent over charge and over discharge of a back-up power source by supervising the voltage of the back-up power source, and automatically controlling the charge and discharge of the back-up power source. CONSTITUTION:When a main power source part 5 is turned off, a voltage detecting part 4 executes voltage switching and power supply is executed from a back-up power source part 2 to an IC memory 9. When it is detected by the voltage detecting part 4 that the voltage of the back-up power source part 2 becomes lower than a voltage which is set in advance, a signal is sent to a relay control part 3 and the main power source part 5 and further, a power source switching signal is sent to a power source switching control part 1. Then, the power supply is executed to the IC memory 9 by the main power source part 5 and the charge is executed to the back-up power source part 2. When the charge to the back-up power source part 2 is completed, the voltage detecting part 4 executes again the power supply to the IC memory 9 by the back-up power source part 2 and the main power source 5 is turned off.</p> |
