Title :
Self-oscillating dimmable electronic ballast to supply two independent lamps
Author :
Costa, M. A Dalla ; Seidel, A.R. ; Bisogno, F.E. ; Prado, R. N do
Author_Institution :
Researching Group of Electron. Ballasts, Univ. Fed. de Santa Maria, Brazil
Abstract :
This paper presents a self-oscillating dimmable electronic ballast to supply two independent lamps. A simple modification in the drive circuit allows dimming of the lamps; this modification consists of just two additional low power passive components. The describing function method and the extended Nyquist criterion are used in the analysis and the design. An improved arrangement of the lamps in the half-bridge topology is done, putting one lamp in each switch of the converter. The advantages of this new arrangement are: if one lamp is damaged, the other keeps working; it has an efficiency improvement when compared to ballasts that supply only one lamp; and the voltage supported by the switches is smaller when compared to the conventional ballasts which supply two lamps in series.
Keywords :
Nyquist criterion; bridge circuits; describing functions; driver circuits; fluorescent lamps; lamp accessories; lighting control; oscillations; describing function method; drive circuit modification; efficiency improvement; extended Nyquist criterion; fluorescent lamps; half-bridge topology; independent lamps supply; low power passive components; self-oscillating dimmable electronic ballast; Circuits; Electronic ballasts; Energy consumption; Feeds; Filters; Fluorescent lamps; Frequency; Switches; Switching converters; Voltage;
Conference_Titel :
Power Electronics Specialists Conference, 2002. pesc 02. 2002 IEEE 33rd Annual
Print_ISBN :
0-7803-7262-X
DOI :
10.1109/PSEC.2002.1023869
