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. 28, 1981
Filed:
Dec. 31, 1979
Applicant:
Inventors:
Gerald J Yachabach, Lakeland, FL (US);
Gary L Eisenhauer, Lakeland, FL (US);
Assignee:
Akzona Incorporated, Asheville, NC (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
179 / ; 179184 ; 361 91 ; 361110 ;
Abstract
A circuit for protecting telephone lines from AC hazardous voltages. The circuit includes an amplitude discriminator triggered at a predetermined voltage level connected to the telephone lines, and providing an output pulse for each zero voltage crossover of the hazardous voltage. A digital pulse counter counts a predetermined number of output pulses from the amplitude discriminator, which in turn operates a switch after the predetermined number of pulses are counted, opening the telephone lines between the central office and the telephone instrument until the hazardous voltage has been removed from the lines.