DRIVE CIRCUIT OF ELECTROSTATIC INDUCTION TYPE SELF ARC-EXTINGUISHING ELEMENT

摘要

PURPOSE: To prevent breakage of an electrostatic induction type self arc- extinguishing element (IGBT) even when load is short-circuited and overcurrents are generated by arc-extinguishing the IGBT after a fixed time when load connected in series with the IGBT is short-circuited and the voltage of the connecting section of load and the IGBT abnormally rises. ;CONSTITUTION: When load 23 is short-circuited and the collector voltage of an IGBT 21 is increased when the IGBT 21 is operated normally, the base voltage of a P-N-P transistor TR 7 is boosted and the TR 7 is turned off. A voltage drop by a resistor is generated and the gate of the IGBT 21 is given one-stage low voltage through N-P-N transistors(TR) 11, 10, and the ON resistance of the IGBT 21 is increased and the currents of the IGBT 21 are reduced. The base voltage of a TR 3 is lowered up to a fixed value after a fixed time composed of a time constant by a capacitor 4 and a resistor 5, and the TR 3 is turned ON and a TR 13 is turned ON. The gate voltage of the IGBT 21 is reduced up to the negative voltage of a DC power supply 2, and an arc is extinguished.;COPYRIGHT: (C)1993,JPO&Japio