BACK-LIGHT INVERTER WITH CURRENT DETECTING FUNCTION OF INDUCTION TYPE

摘要

A back-light inverter having a current detection function of an induction type is provided to maintain a uniform luminance by controlling a lamp current stably and uniformly. A back-light inverter having a current detection function of an induction type includes a driving unit(100), a main transformer(200), a sub transformer(300), a full wave rectifying unit(400), and a driving control unit(500). The driving unit(100) generates a first voltage controlled by a PWM scheme. The main transformer(200) has first and second coils, and converts the first voltage of the driving unit(100) into a second voltage according to a winding ratio of the first and second coils. The main transformer(200) outputs an AC driving current according to the second voltage to a lamp having both ends connected to both ends of the second coil. The sub transformer(300) has a first sub coil which is formed on a current line between the lamp and the second coil of the main transformer(200), and a second sub coil which is induced to the first sub coil. The sub transformer(300) detects a current which flows on the lamp according to a winding ratio of the first and second sub coils. The full wave rectifying unit(400) full-wave-rectifies the current detected by the sub transformer(300). The driving control unit(500) controls a PWM duty of the first voltage based on a voltage from the full wave rectifying unit(400).