The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 20, 1994
Filed:
Feb. 25, 1993
Minoru Tanaka, Yokohama, JP;
Hiroshi Tanimoto, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A bidirectional switch circuit includes a parallel circuit of two unidirectional switch devices which are connected between a first and a second external current terminals. These switch devices are arranged to be reverse to each other in their current-forwarding direction. The switch devices are electrically biased by a single power supply unit, and turn on alternately in accordance with the potential difference between the external terminals. Each switch device may be an insulated gate bipolar transistor (IGBT), which is driven by a bias voltage generator including a resistor. A current flow controller is connected between the power supply unit and the IGBTs, for selectively supplying a control current to one of the IGBTs. A return-current path selector is connected between the external terminals, and has an output connected to the power supply unit through a return path line. The selector automatically performs a return-path changeover operation for a return-current of one of the switch devices being presently turned on.