Title:
PROTECTING DEVICE FOR GATE TURN-OFF THYRISTOR
Document Type and Number:
Japanese Patent JPS61295861
Kind Code:
A
Abstract:
PURPOSE:To alleviate power loss at turning OFF time by bypassing part of a main circuit current which flows to a gate turn-OFF thyristor (GTO) when the GTO is turned OFF. CONSTITUTION:When a switch 3 is closed, a reverse current to that at turning OFF time flows through a resistor 8 from a drive power source 2 to a gate G to turn OFF a GTO 1. At this time, a potential difference generated across the resistor 8 is applied to the base B of a transistor 7, as a positive voltage to an emitter E. Accordingly, a base current IB flows to turn OFF the transistor 7, a part of a main circuit current IT of the GTO 1 flows through a connecting point 9, the transistor 7, a gate drive unit 6 and the connecting point 10 to bypass between the anode A and the cathode K of the GTO 1. Thus, the current duty at turning OFF time is reduced to decrease power loss.
Inventors:
NIWAYAMA KAZUHIKO
Application Number:
JP13961585A
Publication Date:
December 26, 1986
Filing Date:
June 24, 1985
Export Citation:
Assignee:
MITSUBISHI ELECTRIC CORP
International Classes:
H02M1/06; (IPC1-7): H02M1/00
Attorney, Agent or Firm:
Masuo Oiwa