Title :
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
fDate :
4/1/2012 12:00:00 AM
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;
Journal_Title :
Industrial Electronics, IEEE Transactions on
DOI :
10.1109/TIE.2011.2161057