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:
Dec. 07, 1982
Filed:
Nov. 14, 1979
Fredrik Schlyter, Fairfield, CT (US);
DuArt Film Laboratories, New York, NY (US);
Abstract
A system is provided for the simultaneous transmission of two asynchronous base-band logic information signals in opposite directions between first and second information stations using only a single pair of transmission wires, while maintaining electrical isolation between said information stations. The first information station includes a voltage source for driving the transmission line. The source voltage is constant in magnitude but its polarity is determined by the state of the signal being applied to the logic input port of the first information station. The second information station includes circuitry that responds to the polarity of the transmission line voltage and controls the logic output port of the second information station through a photocoupler. The second information station also includes a current sink controlled through a photocoupler by the signal applied to the logic input port of the second information station. The current sink controls the magnitude of transmission line current, which after sensing by circuitry included in the first information station, controls the logic output port of the first information station.