| 摘要 |
PURPOSE:To prevent a power device of an inverter from damaging due to an abnormal overheat by detecting the temperature of the device, and lowering or stopping the output of the inverter if the detected voltage is a predetermined temperature or higher. CONSTITUTION:If the temperature of an arranging part of a thermistor 33 becomes high, the electric resistance of the thermistor 33 gradually increases, and an input voltage (c) to a comparator 31 also rises. If the input voltage C exceeds V0, the input voltage (c) to the comparator 31 is inverted from negative to positive. The comparator 31 is turned OFF by the inversion, and the output (d) of the comparator 31 is opened. When the output (d) of the comparator 31 is opened, the input voltage (e) of a comparator 32 is inverted from negative to positive by VH. The comparator 32 is turned ON by the inversion, and the output voltage (f) of the comparator 32 becomes VL. Thus, a control voltage (z) also becomes VL, and a motor 11 is stopped. |
