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. 09, 1985
Filed:
Dec. 16, 1982
Dewayne A Spires, Plaistow, NH (US);
AT&T Bell Laboratories, Murray Mill, NJ (US);
Abstract
A relay load is connected in the collector path of a first transistor (Q1) of high current carrying capacity. A second transistor (Q2) of similar conductivity type is effectively coupled across the first transistor. The bases of said first and second transistors are connected together. A current mirror circuit (Q3-Q6) is coupled from the collector of said second transistor to said bases to provide the additional base drive necessary to drive the first transistor towards saturation regardless of its Beta when maximum load current is required. The mirror circuit is designed so that the effects of transistor V.sub.be mismatches in the mirror are minimized.