Abstract: Provided are a transformer, capable of simplifying a manufacturing process and enhancing heat dissipation characteristics and insulating characteristics by adopting a dual-bobbin structure and configuring a secondary winding as a metallic plate extending to the outside, and an electronic device including the same. Heat dissipation from a primary winding is facilitated by forming a primary winding at the outer side. Furthermore, a secondary metallic plate, although formed inside, includes extension portions to thereby facilitate heat dissipation from the secondary metallic plate. Also, by adopting a dual bobbin structure for outer and inner bobbins, a sufficient distance for insulation between the primary winding and the secondary metallic plate is ensured to thereby enhance an insulating function. Further, a manufacturing process can be simplified by forming a secondary winding as a metallic plate manufactured in advance.

Abstract: In accordance with the present invention, the switching power supply device using a current sharing transformer includes an inverter switching unit for switching an input voltage; a set of share inductors connected to the inverter switching unit for distributing a current applied by the inverter switching unit; first and second transformers of which each primary side connected to the set of share inductors is connected in parallel to each other; and a rectifying unit connected to secondary sides of the first and second transformers.

Abstract: There is provided a transformer improved in leakage inductance including: a core having first, second and third legs electromagnetically coupled to one another; a primary winding formed of a conductor having one end and another end receiving power from the outside and dividedly wound around the first, second and third legs; and a secondary winding wound around at least one of the first, second and third legs and receiving induced power by electromagnetic induction with the primary winding.

Abstract: The present invention relates to a load sharing device and a parallel power supply therewith. There is provided a parallel power supply, including: a plurality of power supply modules each connected to a single load in parallel to provide balanced output currents to the single load; a common voltage control signal output unit that generates a common voltage control signal from output voltages of the plurality of power supply modules and outputs the common voltage control signals to the plurality of power supply modules; and output voltage control units that are provided in the respective plurality of power supply modules to detect output currents of the plurality of power supply modules and to control output voltages of the plurality of power supply modules according to the detected signals, controlling the output voltages to be in a predetermined voltage range according to the common voltage control signals.

Abstract: The present invention provides a power supply for a server including: a PFC (Power Factor Correction) unit for meeting harmonic regulation by being connected to an input power source; a DC/DC unit including a switching stage provided with at least one switching device to switch a voltage of a link capacitor as an output voltage of the PFC unit to a predetermined operation frequency and a DC/DC stage driven by the switching stage; a DC/DC control unit for controlling the DC/DC unit by being connected to the switching device; and a frequency varying circuit unit for supplying the DC/DC control unit with a frequency control signal to adjust the operation frequency of the switching device according to load after detecting an output current of the link capacitor and acquiring load information.

Abstract: Provided is a transformer having resonant inductance, the transformer including a core that includes a first leg formed in one side thereof, a second leg which is formed in the other side thereof so as to be electromagnetically coupled to the first leg, and a third leg which is formed between the first and second legs so as to be electromagnetically coupled to the first and second legs; a primary winding that is wound around one side of the third leg; a secondary winding that is wound around the other side of the third leg so as to induce power through electromagnetic induction with the primary winding; and a resonant inductance winding that is wound around the outside of the core so as not to be magnetically induced by magnetic fluxes generated from the primary and secondary windings.

Abstract: Provided is a transformer having resonant inductance, the transformer including a core that includes a first leg formed in one side thereof, a second leg which is formed in the other side thereof so as to be electromagnetically coupled to the first leg, and a third leg which is formed between the first and second legs so as to be electromagnetically coupled to the first and second legs; a primary winding that is wound around one side of the third leg; a secondary winding that is wound around the other side of the third leg so as to induce power through electromagnetic induction with the primary winding; and a resonant inductance winding that is wound around the outside of the core so as not to be magnetically induced by magnetic fluxes generated from the primary and secondary windings.

Abstract: There is provided a variable switching frequency type power supply that can achieve high efficiency by fixing a switching duty cycle to 50% and varying switching frequency. A variable switching frequency type power supply according to an aspect of the invention may include: a switching unit switching input power; a transformation unit converting a voltage level of the power switched by the switching unit into a predetermined voltage level; a rectification unit rectifying the power converted by the transformation unit; and a control unit fixing a switching duty cycle of the switching unit to a predetermined switching duty cycle, and varying switching frequency of the switching unit according to a voltage level of output power.

Abstract: A phase shift full bridge converter with a reduced current stress includes: a switching unit that switches an input voltage; a transformer that includes a first capacitor serially connected to, and having a primary side and a secondary side; an auxiliary circuit unit that includes a first switch, a second switch, and a second capacitor, which are connected in parallel to the secondary side of the transformer; and a rectification unit that is connected to the auxiliary circuit unit, with an output inductor being removed.

Abstract: In accordance with the present invention, the SMPS circuit for PDP includes first and second transformers inducing voltages supplied to primary sides to secondary sides; a plurality of DC/DC converters connected to secondary sides of the first and second transformers and supplying voltages of different sizes; a clamp circuit connected to the secondary side of the first transformer and outputting an address voltage of a predetermined size by receiving a voltage supplied from the first transformer; and a linear regulator unit connected to the DC/DC converter for supplying a low voltage among the DC/DC converters connected to the secondary side of the first transformer and outputting a gate voltage of a predetermined size by receiving the low voltage supplied from the DC/DC converter.

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: In accordance with the present invention, the switching power supply device using a current sharing transformer includes an inverter switching unit for switching an input voltage; a share inductor for classification connected to the inverter switching unit for distributing a current applied by the inverter switching unit; first and second transformers of which each primary side connected to the share inductor for classification is connected in parallel to each other; and a rectifying unit connected to secondary sides of the first and second transformers.

Abstract: There is provided a bridgeless power factor correction circuit that corrects a power factor by complementarily switching two switches according to phase of input power without using rectifier bridge diodes. A bridgeless power factor correction circuit according to an aspect of the invention may include: a switching unit having a plurality of switches and alternately switching input AC power; a stabilizing unit rectifying and smoothing the power switched by the switching unit; and a control unit controlling an alternate switching operation between the plurality of switches according to phases of the input power.

Abstract: There is provided a transformer improved in leakage inductance including: a core having first, second and third legs electromagnetically coupled to one another; a primary winding formed of a conductor having one end and another end receiving power from the outside and dividedly wound around the first, second and third legs; and a secondary winding wound around at least one of the first, second and third legs and receiving induced power by electromagnetic induction with the primary winding.

Abstract: Provided is a flyback DC/DC converter for a power supply. In the flyback DC/DC converter, a flyback driver unit provides a primary current. A transformer includes a plurality of secondary coils for inducing energy from the primary coil receiving the primary current. A rectifier unit includes a plurality of rectifier diodes for rectifying secondary currents of the corresponding secondary coils of the transformer. A plurality of clamp diodes are connected in series to the corresponding rectifier diodes of the rectifier unit in a forward direction to clamp ringing voltage across the corresponding rectifier diodes when the power switch is turned off. Accordingly, the voltage across the rectifier diode on the secondary side can be reduced such that it is lower than the output voltage. Also, it is possible to remove the ringing voltage of the rectifier diode and to enhance the efficiency of the flyback DC/DC converter.

Abstract: Provided is a flyback DC/DC converter for a power supply. In the flyback DC/DC converter, a flyback driver unit provides a primary current. A transformer includes a plurality of secondary coils for inducing energy from the primary coil receiving the primary current. A rectifier unit includes a plurality of rectifier diodes for rectifying secondary currents of the corresponding secondary coils of the transformer. A plurality of clamp diodes are connected in series to the corresponding rectifier diodes of the rectifier unit in a forward direction to clamp ringing voltage across the corresponding rectifier diodes when the power switch is turned off. Accordingly, the voltage across the rectifier diode on the secondary side can be reduced such that it is lower than the output voltage. Also, it is possible to remove the ringing voltage of the rectifier diode and to enhance the efficiency of the flyback DC/DC converter.