Method and apparatus for communicating message signals in a load control system
US8471687B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 11, 2011 |
| Grant date | Jun 25, 2013 |
| Priority date | — |
| Expiry date | Oct 11, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/0266
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A system for independent control of electric motors and electric lights includes a plurality of two-wire wallstations coupled in series via power wires between an alternating-current (AC) source and a light/motor control unit. The light/motor control unit is preferably located in the same enclosure as an electric motor and an electric light and has two outputs for independent control of the motor and the light. The light/motor control unit and the wallstations each include a controller and a communication circuit that is coupled to the power wiring via a communication transformer and communicate with each other using a loop current carrier technique. The light/motor control unit and the wallstations utilize pseudo random orthogonal codes and a median filter in the communication process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.