Flourescent lamp with integral proximity sensor for building energy management
US7923936B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 2008 |
| Grant date | Apr 12, 2011 |
| Priority date | — |
| Expiry date | Oct 14, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A fluorescent lamp sensor system is provided. The fluorescent lamp sensor system includes a plurality of bulbs and a plurality of electrodes coupled to the bulbs. A balanced differential circuit measures changes in electric fields produced by the bulbs in front of the electrodes. The balanced differential circuit includes a symmetric current source associated with alternating the surface potential of the bulbs. A current mode detection circuit detects the current associated with the capacitive effects of the balanced differential circuit. A synchronous detection circuit isolates the capacitive effects of the symmetrical current source from stray signals that differ in either frequency or phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.