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. 05, 1978
Filed:
Aug. 09, 1977
Hitachi, Ltd., , JP;
Abstract
A constant current circuit includes two characteristic-correlated PNP transistors connected to a constant voltage source and having common-connected emitters and common-connected bases and an NPN transistor. A constant current is taken out of a collector of a first PNP transistor. A collector of a second PNP transistor is connected to a base of the NPN transistor and the common-connected emitters of the first and second PNP transistors is connected to a collector of the NPN transistor to form a negative feedback circuit in the first PNP transistor, whereby when a current gain of the second PNP transistor which is characteristic corelated to the first PNP transistor is high a large amount of feedback is applied and when the current gain is low a small amount of feedback is applied so that the magnitude of the output constant current taken from the collector of the first PNP transistor is adjusted.