Dimmable Solid State Ballast With Integral Capacitive Occupancy Sensor

Author

Avestruz, Al-Thaddeus ; Cooley, John J. ; Vickery, Daniel ; Paris, James ; Leeb, Steven B.

Author_Institution

Dept. of Electr. Eng. & Comput. Sci., Massachusetts Inst. of Technol., Cambridge, MA, USA

Volume

59

Issue

4

fYear

2012

fDate

4/1/2012 12:00:00 AM

Firstpage

1739

Lastpage

1750

Abstract

This paper describes and demonstrates an LED lighting system with an integral capacitive sensor that can detect occupancy both lighted and in the dark, and a driver (“ballast”) that is dimmable over a wide range. Sensing in the dark is accomplished by taking advantage of the logarithmic relationship between LED voltage and current. The ballast uses an inductor pre-charge technique to maintain efficiency during dimming, while maintaining relevant parameters for quality of lighting (e.g., chromaticity/color cast).

Keywords

capacitive sensors; inductors; lamp accessories; light emitting diodes; lighting; LED current; LED lighting system; LED voltage; dimmable solid state ballast; inductor precharge technique; integral capacitive occupancy sensor; lighting quality; Electrodes; Electronic ballasts; Inductors; Inverters; Light emitting diodes; Lighting; Pulse width modulation; Capacitive sensing; LED driver; dimming; occupancy sensing;

fLanguage

English

Journal_Title

Industrial Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0278-0046

Type

jour

DOI

10.1109/TIE.2011.2161057

Filename

5936716