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:
Apr. 27, 2004
Filed:
Jul. 23, 2002
Eric Lesguillier, Saint-Rédempteur, CA;
Yves Roy, Beauport, CA;
Pierre Longtin, Île d'Orleans, CA;
Domosys Corporation, Quebec, CA;
Abstract
The power line communication system includes a transmitter and a receiver, both providing a communication path between two communication control devices over a power line. The transmitter includes a voltage amplifier and a current amplifier. A switch between the transmit and receive modes is implemented within the voltage amplifier. The current amplifier also has a two-step output impedance. When the transmitter is active, the current amplifier shows a low impedance on the line to overcome other loads. If, however, the communication medium shows a high level of noise, the output impedance of the current amplifier decreases even further and creates a path to ground. The receiver advantageously uses a logarithmic amplifier for signal range compression. This type of amplifier preserves the shape of the signal that is important when the modulation scheme uses the zero crossings to store information. At the receiver, the communications control device mixes a reference signal with signals received on the power line. The mixed signal is then amplified before passing to the receiver output. At the communication control device, the reference signal is demodulated so as to detect whether what is received is noise or a communication signal.