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:
Nov. 15, 1977
Filed:
Jul. 13, 1976
Hitachi, Ltd., , JA;
Abstract
A semiconductor switch is composed of at least a 4-terminal PNPN switch. The cathode gate and the anode gate of the PNPN switch are connected to a current-supplying type constant-current circuit with a power supply for feeding a current into the cathode gate and to a current-sinking type constant-current circuit without any power supply for taking out a current from the anode gate, respectively. A change-over circuit is connected between both the constant-current circits for automatically selecting a path of a drive current from the current-supplying type constant-current circuit to either selected one of the cathode gate and the anode gate or the current-sinking type constant-current circuit in response to the electrical potential of the PNPN switch. The semiconductor switch circuit composed of the 4-terminal PNPN switch may be thus controlled economically with a single power supply without any wasteful power consumption.