| 摘要 |
<p>PURPOSE:To permit a user to know the start of a backup without trouble by providing a means for detecting the start of the memory backup with a backup battery and a means informing the user of the start of the backup. CONSTITUTION:When a battery 1 is mounted to an electronic equipment and connected to a connection terminal 6, the potential-divided output voltage of the battery 1 is applied to the non-inversion input terminal of an operation amplifier 20 and a prescribed reference voltage is applied to an inversion input terminal via a Zener diode 21. When the output voltage of the battery 1 is enough to drive the electronic equipment and also enough to back up the memory 5, the potential-divided output voltageexceeds the reference voltage and an MPU 3 is reset with the output signal of the operation amplifier 20. The reset MPU 3 drives a buzzar 4 to output an initial tone informing of the start of the backup of the memory 5. Thus, the user can easily know the start of the backup without trouble.</p> |
