A Single-Switch High-Voltage Lamp Tester for Cold Cathode Fluorescent Lamps

This paper proposes a novel high-voltage generator served as a lamp tester for cold cathode fluorescent lamps (CCFLs). The proposed circuit consists of a buck-boost converter, an LC resonant network, and a step-up transformer. Only one active switch with simple control for turning on and off the switch at a high frequency is used. The proposed circuit has the advantage of simple configuration, small volume, and low cost. Besides, a high power factor at the ac line source can be obtained by operating the buck-boost converter at discontinuous conduction mode. A prototype circuit was built for testing 19-in CCFLs. It has proved that the proposed lamp tester can test the CCFLs quickly and effectively. Moreover, a test system is set up for obtaining the optical spectrum and the colorimetric values of CCFLs. By comparing the optical spectrum and colorimetric values of the test CCFL with the ones of the normal CCFL, light quality can be easily diagnosed. It provides an effective method to find out the possible defects in the manufacture process.

[1]  Yi-Hwa Liu,et al.  Design and Implementation of an FPGA-Based CCFL Driving System With Digital Dimming Capability , 2007, IEEE Transactions on Industrial Electronics.

[2]  Gerry Moschopoulos,et al.  Single-phase single-stage power-factor-corrected converter topologies , 2005, IEEE Transactions on Industrial Electronics.

[3]  Wei Yan,et al.  A Semi-Theoretical Fluorescent Lamp Model for Time-Domain Transient and Steady-State Simulations , 2007, IEEE Transactions on Power Electronics.

[4]  Wei Yan,et al.  Modeling of Cold Cathode Fluorescent Lamps (CCFLs) With Realistic Electrode Profile , 2010, IEEE Transactions on Power Electronics.

[5]  S. Ben-Yaakov,et al.  Cold Cathode Fluorescent Lamps Driven by Piezoelectric Transformers: Stability Conditions and Thermal Effect , 2007, IEEE Transactions on Power Electronics.

[6]  Hung L. Cheng,et al.  A novel single-stage high-power-factor ac/dc converter featuring high circuit efficiency , 2009, 2009 IEEE International Conference on Industrial Technology.

[7]  C.-C. Chen,et al.  Design and development of digital control multi-lamp back-light modules for TFT-LCD TV , 2005, Fourtieth IAS Annual Meeting. Conference Record of the 2005 Industry Applications Conference, 2005..

[8]  R. Zane,et al.  Low Frequency Architecture for Multi-Lamp CCFL Systems With Capacitive Ignition , 2009, Journal of Display Technology.