RUNAWAY MONITORING SYSTEM FOR MICROCOMPUTER

摘要

PURPOSE:To prevent also a miniaturized computer from generating malfunction by utilizing a phenomenon continuously outputting a high or low signal from an output terminal at the time of generating runaway in a microcomputer and allowing the terminal voltage of any delay circuit to allow a threshold. CONSTITUTION:When voltage is impressed to the microcomputer 1, a high signal for driving a load 14 is outputted from a terminal Q and an output for alternately charging an integrating circuit 16 in the 1st delay circuit 2 and an integrating circuit 17 in the 2nd delay circuit 3 is generated from a terminal P. Thereby, the output voltage of an OR circuit 4 consisting of capacitors C1, C2 is reduced less than the non-operation voltage of a transistor (Tr) Tr3 and both the Trs Tr3, Tr4 are simultaneously connected by the high signal from the terminal Q, so that the relay 9 is excited and a high voltage is impressed to the load 14. If runaway is generated in the microcomputer 1, the output voltage of the circuit 4 is continuously increased and goes an interrupted state after being inverted by exceeding the non-operation voltage of the Tr3 and the relay 9 is disconnected, so that voltage supply to the load 14 is interrupted.