Abstract: Disclosed is a multi-output DC/DC converter controlling power-conversion switching in synchronization with a frequency of one output voltage among multiple output voltages in an LLC resonant DC/DC converter. The multi-output DC/DC converter includes a power conversion circuit performing alternate switching on an input DC voltage to output multiple DC voltages including a first DC voltage and a second DC voltage each having a preset voltage level, and a control circuit controlling the alternate switching of the power conversion circuit in synchronization with a preset resonant frequency.

Abstract: There are provided an integrated transformer in which a power conversion transformer and an inductor for stabilizing output power by the transformer are integrated into one transformer structure, and a power supply using the same. An integrated transformer according to an aspect of the invention includes: a core part including: first and second supports; and first and second outer legs and a center leg provided between the first and second supports, and magnetically connecting the first and second supports to each other, wherein a cross-section of the first and second outer legs and a cross-section of the center leg have a width of the first support and a width of the second support in a longitudinal direction, respectively, and a width of each of the first and second outer legs exceeds 0.5 times a width of the center leg but does not exceed 2 times the width of the center leg.

Abstract: Provided is a power supply device including a power supply unit that supplies a driving voltage for driving at least one or more loads; a current balancing unit that maintains a current balance of the driving voltage supplied to the respective loads; a detection unit that detects currents flowing in the current balancing unit through electromagnetic induction so as to output a detection signal; and a control unit that receives the detection signal to judge whether the loads are opened or not and outputs a control signal for controlling the magnitude of the driving voltage.

Abstract: A direct current (DC) power supply for varying an output voltage according to a load current variation is disclosed. The DC power supply includes an alternating current(AC)/DC conversion unit converting commercial AC power into DC power, a DC/DC conversion unit converting a voltage level of the DC power and outputting output power, and a control unit controlling conversion of the voltage level of the fed-back DC power according to a variation in a load current of the output power from the DC/DC conversion unit.

Abstract: Provided is a DC/DC converter including a power supply unit that includes a transformer having one primary side and a plurality of secondary sides and outputs a plurality of driving voltages for driving a load; and a constant current converting unit that is connected to one secondary side and a low-voltage stage of another secondary side adjacent to the one secondary side among the plurality of secondary sides of the transformer and boosts a driving voltage output from the one secondary side.

Abstract: There is provided a backlight driving system for a liquid crystal display that can reduce size and weight of a product because a DC-DC converter is not used when commercial AC power is converted into lamp driving power. A backlight driving system for a liquid crystal display according to an aspect of the invention includes a power supply unit converting commercial alternating current (AC) power into direct current (DC) power having a voltage level set beforehand, an inverter unit converting the DC power from the power supply unit into AC power at a one-to-one conversion ratio set beforehand, a boosting unit boosting the AC power from the inverter unit into lamp lighting power set beforehand; and a lamp group receiving the lamp lighting power from the boosting unit to emit light.