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:
Mar. 06, 1984
Filed:
Nov. 01, 1982
Applicant:
Inventors:
Gary Grantland, Hartselle, AL (US);
Eduard F Boeckmann, Huntsville, AL (US);
Assignee:
GTE Automatic Electric Inc., Northlake, IL (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
179 / ; 179 / ;
Abstract
In a hold circuit connectable to a subscriber telephone line, a line voltage storage capacitor is momentarily connected to the subscriber line charging to line potential and providing trigger current to a silicon controlled rectifier. When sufficient trigger current is gained the silicon controlled rectifier turns on discharging the capacitor through a latching relay coil and a transistor, thereby turning on the relay and connecting the hold circuit. The transistor is turned on by a bias voltage from the capacitor when the silicon controlled rectifier is turned on.