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:
May. 28, 2013
Filed:
May. 30, 2008
Kelly C. Casey, Flower Mound, TX (US);
Kelly C. Casey, Flower Mound, TX (US);
Littelfuse, Inc., Chicago, IL (US);
Abstract
A protection circuit employing a pair of SCR devices connected respectfully from telephone line tip conductor and ring conductors to ground. The SCR devices are of the type providing internal semiconductor resistors between the gate and cathode terminals for sensing overcurrents in the telephone line conductors, and providing voltage sensitive semiconductor regions so that the SCR devices are sensitive to overvoltages on the telephone line conductors. A pair of diodes are connected across the cathode-anode terminals of the SCR devices to provide overvoltage protection for positive polarity overvoltages on the telephone line.