Abstract: A gate driver, which drives an N-channel type transistor connected between an application terminal of an input voltage and an application terminal of a switch voltage, includes a capacitor circuit connected between an application terminal of a boot voltage higher than the switch voltage by a voltage between both ends of the boot capacitor and the application terminal of the switch voltage, and a timing control circuit that charges an input gate capacitance of the transistor with the boot voltage after precharging the same with the input voltage during turn-on transition of the transistor, and decreases capacitance value of the capacitor circuit after the turn-on transition of the transistor.

Abstract: A gate driver, which drives an N-channel type transistor connected between an application terminal of an input voltage and an application terminal of a switch voltage, includes a capacitor circuit connected between an application terminal of a boot voltage higher than the switch voltage by a voltage between both ends of the boot capacitor and the application terminal of the switch voltage, and a timing control circuit that charges an input gate capacitance of the transistor with the boot voltage after precharging the same with the input voltage during turn-on transition of the transistor, and decreases capacitance value of the capacitor circuit after the turn-on transition of the transistor.

Abstract: A narrow gap arc welding process comprises steps of defining a narrow gap between a pair of members to be welded arranged so as to face each other at a predetermined distance, feeding a consumable electrode into a guide cylinder which is movable along the narrow gap, and generating electric arc between the tip of the consumable electrode and the members to be welded to unite them with each other, wherein the consumable electrode, while being deformed plastically to have a wave-like pattern with a pitch of about 10 to 30 mm and a molding width of about 2 to 5 mm depending on welding conditions, is fed into the narrow gap with the direction of the molding width being in line with the direction of the width of the narrow gap and the direction of the tip of the consumable electrode being changed so as to point out one after the other facing edge of the members to be welded alternately at a high frequency. Also, an apparatus for practicing the process is described.