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. 16, 1996
Filed:
Jul. 27, 1992
Chinnarao Mokkapati, Export, PA (US);
Ronald R Capan, Pittsburgh, PA (US);
Union Switch & Signal Inc., Pittsburgh, PA (US);
Abstract
A vital railway signal link for passing DC signals between a first terminal location and a second terminal location. A transmitter at the first terminal location receives a DC input signal and responsively produces a light signal modulated at a preselected frequency. The light signal is conducted through an optical fiber to the second terminal location. There, a receiver detects the light signal and produces a DC output signal. The receiver contains discriminator circuitry preferably including a bandpass filter to prevent light signals other than those modulated at the preselected frequency from giving an output signal.