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:
Feb. 20, 1996
Filed:
Sep. 03, 1991
Melvin A Lace, Prospect Heights, IL (US);
Other;
Abstract
Surge protection for a data transmission line, typically a telephone line including two data signal conductors, incorporates a primary protector circuit for high voltage, high energy surges and a secondary protector circuit for low voltage surges. The primary protector circuit includes a normally non-conductive 'breakdown' or 'crowbar' device having a high breakdown voltage, a solid-state triac, or a thyristor, driven conductive by a surge exceeding its breakdown voltage; the crowbar device is connected from one or both conductors to ground. An inductance is connected in the circuit to extend the time in which the circuit reduces a surge to near zero voltage, and thus dissipates power from the surge. The second protector circuit includes at least one avalanche diode, Zener diode, or other threshold device in parallel with the primary protector circuit. The threshold device(s) in the secondary circuit have thresholds much lower than the primary breakdown voltage; typical values are ten to seventy volts for the threshold devices and two to three hundred volts for the primary breakdown devices. In all instances, impedances, particularly resistances, in series in the data signal conductors are avoided. The spacing between the primary and secondary protector circuits is at least two meters.