| 摘要 |
PROBLEM TO BE SOLVED: To detect an open failure of a diode for a device for detecting the end temperature of a temperature detection object, based on the both end voltages of the diode. SOLUTION: The diode D1 is arranged near the IGBT 10 that is the temperature detection object. When the temperature of the IGBT 10 rises higher than the predetermined temperature, both the end voltages of the diode D1 are lowered accompanying the temperature rise of the diode D1, therefore the output signal of the comparator 2 changes from Hi level to Lo level. If the open failure of the diode D1 occurs, the current I3 flowing in the resistance circuit 30 which is connected parallel to the diode D1 increases, and the MOSFET 20 of N channel is turned ON, so that the input signal to the controller 40 outputted by the comparator 2 turns Lo indicating the occurrence of abnormality. COPYRIGHT: (C)2007,JPO&INPIT |
