| Title |
A Study on the Low-Cost Device for Improving the Drive Failure of External Electrode Lamp in the Dark States |
| Authors |
Myung-Hwan Kim ; Jae-Jung Yun |
| DOI |
http://dx.doi.org/10.5207/JIEIE.2018.32.2.024 |
| Keywords |
Dark Driving Failure ; External Electrode Fluorescent Lamp(EEFL) ; Inverter ; LCD Backlight |
| Abstract |
LCD backlight which uses the external electrode fluorescent lamps (EEFLs) connected in parallel has a problem that some lamps are not turned on during the initial drive in the dark state. To solve this problem, the conventional method uses lights emitted from LEDs which are driven by an electric circuit consists of a DC power source and several passive and active components, because LED lights can help the lamps to turn on easily. This paper proposes a new low-cost device for improving the dark drive failure of EEFLs without a DC source and an electric circuit. The proposed device consists of a LED, a diode, and a metal line and is installed on the PCB board which is used to drive EEFLs connected in parallel. The operation principle is to drive LEDs with the induced LED driving voltage on the floating metal line of the proposed device from the high voltage and high frequency EEFL driving voltage. To verify the operation of the proposed device, it is tested on a 42-inch LCD backlight which driven by the inverter producing the EEFL driving voltage having the operating frequency of 45kHz and rms value of 1000Vrms. As a result of the experiment, the LED lights were emitted simultaneously with the initial lighting of the LCD backlight by the proposed device and the measured LED current was 2.4mArms in the case of the metal pattern of 3mm width and 250mm length. |