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. 04, 1989
Filed:
Aug. 17, 1987
Dan I Hariton, Pinole, CA (US);
Prasanna M Shah, Sunnyvale, CA (US);
Signetics Corporation, Sunnyvale, CA (US);
Abstract
A transceiver system for high speed, low bit-error rate data communications over a.c. power lines in the presence of repetitive impulse noise includes an a.c. power line coupling network, a power line communications modem, and a microprocessor with a memory and a programmed avoidance algorithm. The a.c. line coupling network includes a zero crossing circuit to detect the start of each a.c. cycle; a transient-voltage limiting front end to detect impluse noises above a threshold and minimize ringing, and a timing circuit to determine the time and duration of each impulse in each sampled a.c. cycle. The microprocessor records the start and stop times of impulses, repetitively scans several a.c. cycles and determines whether or not the impulses are periodic. For periodic impulses, the microprocessor blocks communication on the modem during the impulses, enabling the transceiver to transmit and receive between impulses.