| 摘要 |
PROBLEM TO BE SOLVED: To monitor a temperature abnormality in the entire period by detecting an abnormal temperature by means of an alarming temperature set value after a power source is turned on and before the temperature in a base reaches a steady-state temperature and detecting an abnormal temperature by means of a different set value after the steady-state temperature is achieved. SOLUTION: A timer 74 measures the time of a transient period T1 immediately after a power source is turned on in response to a source on signal 72 before a temperature in a base is brought by a thermostat device to a predetermined steady-state temperature. After this time has passed, an enable signal 74s is outputted and supplied to a selection control input terminal of a multiplexer 45. The multiplexer 45 inputs an alarming temperature set value D1a in a transient period T1 and an alarming temperature set value D1b in a steady-state period T2 to a comparator 46. A temperature detection signal 52 from a temperature sensor is converted by quantization at an A/D converter 42 thereby obtaining a temperature data D42. The comparator 46 compares the alarming temperature set value D1a with the temperature data D42 in the transient period T1 and the alarming temperature set value D1b in the steady- state period T2, with outputting an alarming signal 49 to indicate a temperature abnormality when the temperature data D42 are higher.
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