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:
Oct. 19, 1982
Filed:
Apr. 09, 1981
John S Phillips, Raleigh, NC (US);
Waymon A Melvin, Jr, St. Matthews Twsp., NC (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
A receiver for a distribution network power line carrier communication system is magnetically coupled to a distribution power line. A carrier signal, phase-shift keyed modulated by an information signal and carried by the distribution power line, is thereby coupled to the receiver circuitry. A first receiver amplification circuit includes an automatic gain control circuit, to prevent saturation of the receiver electronics, and a feedback circuit to determine the gain. The automatic gain control circuit utilizes a field effect transistor which cooperates with the amplifier's feedback circuit to modify the gain. The drain source resistance of the field effect transistor is varied in accord with the magnitude of the received noise or modulated carrier signal to lower the amplifier's gain when excessive positive or negative noise or modulated carrier signal peaks are encountered. The modulated carrier signal is then processed through several filter stages and further amplified. Finally, the information signal is removed from the modulated carrier by a phase shift keyed demodulator. The information is available for input to a remote device which is responsive thereto for performing any of a variety of automated functions.