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:
Apr. 11, 1978
Filed:
Sep. 28, 1976
Shinzi Okuhara, Fujisawa, JA;
Ichiro Ohhinata, Yokohama, JA;
Tatsuya Kamei, Hitachi, JA;
Masayoshi Suzuki, Hitachi, JA;
Hitachi, Ltd., , JA;
Abstract
A stable semiconductor switch comprising a PNPN switch, a transistor, a driving device, and diodes. The PNPN switch is composed of four-layered PNPN structure and has three PN-junctions, an anode, an anode gate, a cathode gate, and a cathode. The collector and the emitter of the transistor are connected to the cathode gate and the cathode of the PNPN switch, respectively. The driving device has its one end connected to the anode gate of the PNPN switch and its other end connected to the base of the transistor so as to drive the transistor in transient state. The diodes are connected between the driving device and the emitter of the transistor in a manner so that, when the PNPN switch is controlled to fire and a back current tends to flow through the PNPN switch temporarily, the back current does not flow through the transistor so as to prevent the transistor from causing any abnormal actions such as oscillation.