| 摘要 |
<p>PURPOSE:To really detect a voltage in a memory backup condition and to prevent an accident to erase the contents of a memory by detecting a voltage at the backup time of a memory backup battery to be charged in an integration circuit. CONSTITUTION:An integration circuit 9 is provided between a memory backup battery 2 and a detector 3 and the voltage at the back up time of the memory backup battery 2, which is charged in the integration circuit 9, is detected by the detector 3 when a power source is turned on. Thus, since the voltage of the memory backup battery 2 in the real memory backup condition is held to the integration circuit 9 when the main power source is turned off, correct decision is executed by the detector 3 and danger to erase the contents of a memory 1 can be reduced when the main power source is turned off.</p> |
