Patent attributes
In a temperature protection device for power devices of the present invention, detected temperatures of power devices are compared with respective threshold values by determination units. If either one of the determination units determines that there is abnormal heat build-up of the respective power devices, the output of that determination units is maintained by a latch circuit, and the current carried by the power device subject to abnormal heat build-up is interrupted. In addition, due to the output of the determination units making the determination, the threshold value of the other determination units is changed to a temperature threshold value that is higher than that set previously, so that it is not determined that the normally operating power device is subject to abnormal heat build-up. This changing of the threshold value is only executed for a fixed time period based upon a timer circuit.
