| 摘要 |
PROBLEM TO BE SOLVED: To properly stop a machine when an abnormal signal is inputted by connecting a signal input to at least one relay through two capacitor, and having these capacitors alternately discharged toward the relay, in this monitoring circuit continuously monitoring four input signals. SOLUTION: A monitoring circuit 1 is provided with four signal inputs Z1 to Z4, and at a first phase, positive potential appears in the two signal inputs Z3 and Z4, and when earth potential has appeared in the signal inputs Z1 and Z2, it is so designed that a capacitor C43 is charged but another capacitor C41 is discharged. Three transistors V161, V165 and V169 are controlled by the potential appearing in the signal inputs Z3 and Z4, and when two transistors V169 and V179 are controlled, the capacitor C43 is discharged to two relays K1 and K2. A second phase gets up at each specified interval with this first phase, and at this second phase, two transistors V167 and V181 are controlled, the capacitor C41 is discharged to both the relays K1 and K2. This dischargedness is monitored through the relays K1 and K2, and when there is no discharge, a machine is stopped. |
