| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a failure detection device capable of certainly and highly accurately detecting a failure of a circuit element constituting an input circuit from a sensor (detection) resistor to a control means such as a CPU. <P>SOLUTION: The failure detection device comprises the input circuit 13 that is connected to a temperature sensor 53 for detecting various variations and detects the resistance of the temperature sensor 53, a monitoring circuit 14 that is connected to the input circuit 13 in parallel and monitors the failure of the circuit 13, and the CPU 1 that receives the resistance of the temperature sensor 53 detected by the input circuit 13 and switches between an input state of inputting a signal from the monitoring circuit 14 and an output state of outputting a signal to the monitoring circuit 14 when a failure of the monitoring circuit 14 is detected. The CPU 1 switches the monitoring circuit 14 from the input state to the output state when a failure of the monitoring circuit 14 is detected, and determines the failure of the monitoring circuit 14 when difference between the A/D conversion value of the input circuit 13 before the switching and the A/D conversion value of the input circuit 13 after the switching is not within a predetermined range. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
