Abstract: A lamp driving device includes first, second, and third voltage converters. The first voltage converter converts a direct current (DC) power voltage to a first pulse voltage. The second voltage converter converts the DC power voltage to a second pulse voltage. The third voltage converter generates a high alternating current (AC) voltage based on the first and second pulse voltages. The lamp driving device generates the high AC voltage without a transformer, so that a manufacturing cost of a display apparatus adopting the lamp driving device may be reduced.

Abstract: A lamp driving device includes first, second, and third voltage converters. The first voltage converter converts a direct current (DC) power voltage to a first pulse voltage. The second voltage converter converts the DC power voltage to a second pulse voltage. The third voltage converter generates a high alternating current (AC) voltage based on the first and second pulse voltages. The lamp driving device generates the high AC voltage without a transformer, so that a manufacturing cost of a display apparatus adopting the lamp driving device may be reduced.

Abstract: A switch coupled active forward converter comprising an AC power supply circuit for supplying AC power, a filtering circuit connected to the AC power supply circuit, for filtering an output current from the AC power supply circuit, an up converter connected to the filtering circuit, for generating a saw tooth wave signal in response to an output voltage from the filtering circuit, the saw tooth wave signal having a peak value following an input voltage to the AC power supply circuit when a switch ON operation is performed, a clamping circuit connected in common to the up converter, AC power supply circuit and filtering circuit, for clamping an output voltage from the up converter to a desired level, a transformer having a primary coil connected to the up converter, and an output circuit connected to a secondary coil of the transformer.

Abstract: A high-power factor series resonant rectifier circuit comprising a first rectifier for rectifying an AC input power, a push-pull switching circuit for changing a polarity in the output of the first rectifier in response to a resonant frequency, an isolation transformer for transforming the output of the push-pull switching circuit, an LC resonance tank for resonating the output of the isolation transformer, a second rectifier for rectifying the output of the LC resonant tank, and a boost chopper switch connected in parallel to the output of the second rectifier. The boost chopper switch performs a switching operation when a resonant current becomes zero, resulting in an increase in power density. The increase in power density results in a reduction in switching loss. Therefore, the rectifier circuit of the present invention is operable at a high frequency.