| 摘要 |
PURPOSE:To be able to detect the power interruption and recovery by unit circuit by prepairing the auxiliary power in addition to the main power and by obtaining the detecting signal faster than the main power when interruption and slower than it when recovery. CONSTITUTION:When throwing in the main power or when recovering, the large capacity condenser C1 is charged slowly by the rectified circuit D1 and the output is obtained at the output terminal 2 via regulator 1, capacitor C2. On the other hand, the output of the rectifying circuit D2 of the auxiliary power charges the small capacity condenser C3 quickly. When the charging voltage exceeds the predetermined value, Tr1 turns ON and Tr2 turns OFF. By this, the capacitor C4 is charged slowly, and after stabilizing the voltage of main power, Tr3 turns ON. And the detecting signal for recovery can be obtained from the output terminal 3. Next, when power failure, the capacitor C3 discharges quickly and reaches zero level due to its small capacity. So, the detecting signal can be obtained from the output terminal 3 before interruption of the main power. By these, it can be possible to protect the contents of memory when power interruption and to start operation after stabilizing the circuit when recovery. |
