Title:
DRIVE CIRCUIT FOR INVERTER
Document Type and Number:
Japanese Patent JPS60245477
Kind Code:
A
Abstract:
PURPOSE:To prevent a transistor from damaging due to a reverse bias by constructing to increase a safe operation range without applying the reverse bias to the transistor at the moment of the initial time of a malfunction by the abnormal voltage output. CONSTITUTION:When a photocoupler 2a is turned ON at a malfunction time and a switch 2 is operated, a negative side of a battery 32 is connected to the base through the switch 2 to become reverse bias applied state. Since a malfunction detector 4 operates at this time to supply a bias current to a bypass transistor 51, the reverse bias current from the switch 2 is absorbed during the moment corresponding to the charging period of a capacitor 53, and the reverse bias current is not flowed to a transistor 1. Accordingly, since the transistor 1 is operated in a safe operation range of wide forward bias time of a range wider than the safe operation range at reverse bias time, the transistor 1 might not be damaged even if an overvoltage is generated.
Inventors:
OOGAMI MASAKATSU
YAMAMOTO SHIYOUKOU
YAMAMOTO SHIYOUKOU
Application Number:
JP9960284A
Publication Date:
December 05, 1985
Filing Date:
May 17, 1984
Export Citation:
Assignee:
MITSUBISHI ELECTRIC CORP
International Classes:
H03K17/16; H02M7/537; H03K17/60; (IPC1-7): H03K17/16; H03K17/60
Attorney, Agent or Firm:
Hiroaki Tazawa