Abstract: A backlight inverter using electromagnetic induction and full-wave rectification at a second side of a main transformer includes a drive unit for generating a first voltage and a main transformer having first and second coils. The main transformer converts the first voltage from the drive unit into a second voltage, and outputs an AC current of the second voltage to both ends of a lamp. An auxiliary transformer has a first auxiliary coil formed on a current line connecting between the second coil of the main transformer and the lamp and a second auxiliary coil inductively coupled with the first auxiliary coil. The auxiliary transformer detects the current flowing to the lamp. A full-wave rectifier rectifies the current detected by the auxiliary transformer, and a drive controller controls the PWM duty of the first voltage based on a voltage from the full-wave rectifier.

Abstract: The present invention relates to a transformer. In the transformer, secondary winding sections are placed in both sides of a primary winding section, all terminals of the secondary winding sections are used as output terminals, and an input terminal is placed in the opposite side to the output terminals. Therefore, a return wire in the high-voltage output side does not need to be provided, and a sufficient insulation separation distance is secured in the relation with a printed circuit board, which makes it easy to implement a circuit. Further, improved efficiency is obtained over a conventional transformer, there is a significant reduction in cost, and products using the transformer can be small in size.