| 摘要 |
PURPOSE:To prevent a switching board from malfunction, by suppressing an output from an operation switch for a fixed period after depressing the operation switch to forcedly prepare the time to check the effectiveness of the depressed switch. CONSTITUTION:Output signals from operation switches (SWs) 1-1-1-n, a cancell SW2 which cancels the registration of the depression of the operation SWs and an enable SW3 which makes the outputs of the operation SWs available are respectively applied to filter circuits 4-1-4-n, 42, 43 to convert these output signals into logical levels. If the SW1-1 is closed, a square wave SW signal (a) through the circuit 4-1 is inputted to a storage circuit 6-1 and a timer circuit 7-1. When the circuits 6-1, 7-1 are raised at the trailing edge of the signal (a), a signal (b) and a signal (c) having prescribed time width are outputted respectively and the signal (b) is interrupted by a gate 8-1 during the operation period of the signal (c). After completing the operation of the signal (c), the remaining component of the signal (b) closes the SW3 through the gate 8-1, and a signal (f) which is applied with AND gate 9-1 by signal (e) through a circuit 43 drives a driving circuit 11-1. At that time, a detecting circuit 10-1 detects the trailing edge of the sigal (f), resets the circuit 6-1 through the gate 5-1 and raises the signal (b). |
