Abstract: There are provided a single stage forward-flyback converter, and a power supply apparatus capable of increasing power factor correction and power conversion efficiency. The single stage forward-flyback converter includes: a forward converter unit including a transformer having a primary winding receiving input power and a first secondary winding magnetically coupled to the primary winding to receive power induced thereto, and converting the power in a forward scheme; and a flyback converter unit sharing the transformer, including a second secondary winding, and converting the power in a flyback scheme, wherein the forward converter unit is selectively operated according to a voltage level of the input power.

Abstract: There is provided a switching mode power supply including: a direct current (DC)/DC converting unit converting a DC power level; an auxiliary power supply unit discharged in a no load mode in which a load is not connected to an output terminal of the DC/DC converting unit; and a controlling unit sensing a change in impedance according to whether or not the load is connected to the output terminal to thereby determine whether or not the switching mode power supply is in the no load mode, and driving a pulse width modulation integrated chip (PWM IC) when a voltage level of the auxiliary power supply unit is at a preset level or less in the no load mode.

Abstract: A switching mode power supply includes an EMI filter unit, a PFC unit, a DC/DC unit, a PFC controller including a feedback stage to which a link voltage at an output side of the PFC unit is fed back and an overvoltage protection stage, a DC/DC controller generating a burst mode operation signal in a light-load or no-load condition, an error signal generation unit for sensing an output voltage of the power supply to generate an error signal, and a control unit for enabling the PFC unit to operate in a burst mode by connecting the overvoltage protection stage and the feedback stage. When the error signal is smaller than a predetermined value, the DC/DC controller generates the burst mode operation signal. When the link voltage fed back to the feedback stage exceeds a threshold voltage of the overvoltage protection stage, the PFC controller deactivates the PFC unit.

Abstract: An adapter power supply includes an AC/DC converter converting a commercial AC power into a DC power; a DC/DC converter including a transformer composed of a primary terminal and a secondary terminal in order to output an output power by converting a link voltage of the DC power; and a controller presuming a load current of the output power through a primary current of the transformer and varying the link voltage of the DC power according to variation of the estimated load current.

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: An advantage of the present invention is to provide an adapter power supply which varies a link voltage of DC power serving an input power of a DC/DC converter according to variation of a load current estimated by measuring a secondary current using a lossless current measurement technique at a primary terminal of a transformer of the DC/DC converter and thus presuming a load current of an output power. An adapter power supply according to present invention may include an AC/DC converter converting a commercial AC power into a DC power; a DC/DC converter including a transformer composed of a primary terminal and a secondary terminal in order to output an output power by converting a link voltage of the DC power; and a controller presuming a load current of the output power through a primary current of the transformer and varying the link voltage of the DC power according to variation of the estimated load current.

Abstract: The present invention relates to an adapter power supply, which includes a switching unit for switching a DC voltage; a transformer which has a primary winding connected to the switching unit, a secondary winding electromagnetically coupled to the primary winding, and an auxiliary winding electromagnetically coupled to the primary winding; a rectifier for rectifying a voltage outputted from the transformer; and a controller for controlling the switching unit to operate according to the PWM scheme in a normal operation mode, and to operate according to a quasi-resonant scheme in a standby mode, by detecting information of a load connected to the rectifier.

Abstract: In accordance with one aspect of the present invention to achieve the object, there is provided a switching mode power supply for reducing standby power including an EMI(Electro-Magnetic Interference) filter unit for removing a high frequency noise component by being connected to an input power source; a PFC(Power Factor Correction) unit connected to the EMI filter unit; a DC/DC unit connected to the PFC unit; a synchronous rectifier unit connected to the DC/DC unit; a PFC controller connected to the PFC unit and provided with an overvoltage protection stage; a DC/DC controller which is connected to the DC/DC unit and generates a burst mode operation signal; a synchronous rectifier controller for controlling the synchronous rectifier unit by being connected to the synchronous rectifier unit; an error signal generation unit for sensing an output voltage to generate an error signal and then transmitting the error signal to the DC/DC controller; a control unit for synchronizing the DC/DC unit and the PFC unit so

Abstract: An advantage of the present invention is to provide an adapter power supply which varies a link voltage of DC power serving an input power of a DC/DC converter according to variation of a load current estimated by measuring a secondary current using a lossless current measurement technique at a primary terminal of a transformer of the DC/DC converter and thus presuming a load current of an output power. An adapter power supply according to present invention may include an AC/DC converter converting a commercial AC power into a DC power; a DC/DC converter including a transformer composed of a primary terminal and a secondary terminal in order to output an output power by converting a link voltage of the DC power; and a controller presuming a load current of the output power through a primary current of the transformer and varying the link voltage of the DC power according to variation of the estimated load current.

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.