Lcd's cover a wide range of applications including led tv's to cmputer monitors, PDAs, digital monitors and much more. Lcd Backlight mainly consists of a light source, diaphragm, light leading board and a plastic frame. Cold-cathode fluorescent lamps (CCFLs) have a phosphor coated glass cylinder with cathodes at each end. The CCFL inverter accepts a low-level DC input voltage and provides a high-level AC output to run the backlight Ccfl tube. Here's a CCFL tester circuit that often needed to check a faulty LCD backlight circuit for finding the dead components.
| Circuit schematic of CCFL tester. |
The ciruit is portable6V battery operated and can be used to test almost all types of LCD Backlight Ccfl tubes.Here the NE555 timer IC is working as an astable multivibrator. This drives to drive a standard MOSFET T1 (IRF 512/IRF 830). Here an ordinary step-down transformer is used as the inverter transformer by reversing its primary and secondary windings.
