Apparatus for driving cold cathode fluorescent lamps

Abstract

A starting voltage adjustment circuit (70), which can vary starting voltages to CCFLs (40) according to variations in the temperature of the immediate environment, is employed in an apparatus for driving CCFLs. The starting voltage adjustment circuit includes a zener diode (710), a thermal resistor (720), and a voltage dividing resistor (730) connected in series between a buck converter, a resonant boost converter, and ground. The starting voltage adjustment circuit also includes a control chip (740) which includes pins, of which one is connected between the thermal resistor and the voltage dividing resistor and outputs a constant voltage, and another is connected between the voltage dividing resistor and ground. The thermal resistor has a voltage drop thereacross varying with the temperature. The starting voltage adjustment circuit adjusts an input voltage to the resonant boost converter, thereby adjusting the starting voltage to the CCFLs according to variations in temperature.

Dependencies are inferred from the claim text.