| 摘要 |
<p>A backup power supply 7 is connected to a load via a switching circuit. When the supply of electric power from a main power supply is stopped, the backup power supply 7 supplies electric power to the load 8. When a given manual operation is performed, the switching circuit disconnects the backup power supply 7 from the load 8. When electric power is supplied form the main power supply 6 to the load 8, the switching circuit connects the preliminary power supply 7 to the load 8. The switching circuit is powered by the backup power supply 7.</p> |
