| 摘要 |
PURPOSE:To control the conduction to the controlled unit for an optional preset time regardless of the service interruption and without using any back-up accumulator. CONSTITUTION:Down-counter 2a incorporating semiconductor nonvolatile memory 2M memorizes the contents of counter 2 via the input signal of terminal R/W. The contents is read out by the input signal of R/W when the service interruption is released to be preset to counter 2 in the form of the contents equal to that before the service interruption. The pulse is generated (1) by start signal ST1 or ST2, and counter 2 begins down-counting again with the count contents right before the service interruption as the starting point. When the contents of counter 2 becomes zero, the borrow signal B is transmitted to stop pulse generation 1. Then relay circuit 3 is driven to turn on or off power source E of controlled unit L. |
