| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem in a control method, where a temperature of a semiconductor device is detected by a thermistor and the on/off control of a fan is carried out, when the detected temperature exceeds a range of set temperature, cannot protect the semiconductor device from anomalies in temperature cycle and in a thermistor circuit which are applied to the semiconductor. SOLUTION: In order to protect a semiconductor device 9 from thermal breakdown by the on/off control of a fan 10, the temperature values detected by a thermistor 11 are read (S1), and a deviation ΔT, between the lowest temperature in a set time and the present detected temperature value, is obtained (S2 and S3). If the deviation ΔT is larger than an on-condition differential temperature ΔTon (S4), the fan is turned on (S5); if the deviation ΔT is smaller than an off-condition differential temperature ΔToff (S6), the fan is turned off (S7). An integral value of a load current can correspond to the temperature detected by the thermistor, anomalies, such as contact failure of a thermistor circuit, etc., can be detected, and the thermistor circuit is dispensed with eliminated. |
