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:
Jul. 19, 1988
Filed:
Mar. 02, 1987
Thomas McCartney, Bannockburn, IL (US);
Oneac Corporation, Libertyville, IL (US);
Abstract
Overvoltage protection circuits are provided for coupling a subscriber's station to first and second conductors connected to a telephone system or other similar communications source. The overvoltage protection circuits include first circuitry connected between the first and second conductors for conducting current at a first breakdown voltage and for blocking current below the first breakdown voltage; second circuitry for conducting current at a second breakdown voltage and for blocking current below the second breakdown voltage; and circuitry connected in series between the first and second circuitry for filtering voltage signals on the first and second conductors responsive to the second circuitry conducting current. The overvoltage protection circuits are effective for suppressing noise and transient voltage signals occurring above the data signal and do not require a transient voltage signal to exceed the ring signal for operation.