| 摘要 |
PURPOSE:To prevent the malfunction of a controller due to noise by equipping a safety circuit with a frequency detecting circuit which detects the frequency of a reset signal, and then automatically stopping program control only when the reset signal is generated frequently. CONSTITUTION:When an internal combustion engine is normally under program control, no reset signal is outputted, so a safety circuit 10 is not in operation. If noise is generated and a program counter gets out of order, the program counter refers to an empty area, so the reset signal is outputted. Then, the safety circuit 10 is put in operation to turn off the switch 51 of a relay 50, and each actuator 3 is powered down, thus stopping the program control. |
