Premium
Trans‐admittance control for eliminating the temperature effect of piezoelectric transformer in the CCFL backlight module
Author(s) -
Lo YuKang,
Pai KaiJun,
Chiu HuangJen
Publication year - 2008
Publication title -
international journal of circuit theory and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.364
H-Index - 52
eISSN - 1097-007X
pISSN - 0098-9886
DOI - 10.1002/cta.476
Subject(s) - cold cathode , backlight , inverter , resonant inverter , electrical engineering , transformer , inductance , admittance , materials science , engineering , optoelectronics , voltage , cathode , liquid crystal display , electrical impedance
A half‐bridge (HB) resonant inverter for driving a cold cathode fluorescent lamp (CCFL) backlight module with a piezoelectric transformer (PT) is analyzed in this paper. The resonant inductance of the HB inverter is expressed as a function of the load current, the load resistance and the PT circuit parameters. Also, the trans‐admittance of the PT‐CCFL combination network is measured to track the operating frequency for the HB resonant inverter, which may be varied due to the temperature rise of PT. The lamp driving current and power can thus remain almost constant in a wide temperature range. Experiments show that the observed results match the theoretical analyses. Copyright © 2008 John Wiley & Sons, Ltd.