Patent ID: 8487668

Claim:
A semiconductor drive device characterized by including: a turn-on drive circuit including a forward biasing power source, a first switching element, and a turn-on gate resistor for turning on a semiconductor element; and a turn-off drive circuit including a reverse biasing power source, a second switching element, and a turn-off gate resistor for turning off the semiconductor element, wherein the forward biasing power source and reverse biasing power source are connected in series, a first series circuit of a first thermistor thermally joined to the turn-on gate resistor and a first resistor connected in series is connected between the positive electrode of the forward biasing power source and the negative electrode of the reverse biasing power source, or between the positive electrode and negative electrode of the forward biasing power source, and a second series circuit of a second thermistor thermally joined to the turn-off gate resistor and a second resistor connected in series is connected between the positive electrode of the forward biasing power source and the negative electrode of the reverse biasing power source, or between the positive electrode and negative electrode of the reverse biasing power source, and wherein there is provided means of turning off the first or second switching element when the temperature of either one of the turn-on gate resistor or turn-off gate resistor rises to or above a predetermined value.