Abstract: The invention relates to a power conversion system, wherein a first switch is connected between a input voltage source and a second switch, wherein the second switch is connected to a third switch wherein the third switch is connected to a fourth switch, wherein the fourth switch is connected to the input voltage source, wherein a first diode is connected between a neutral point and the second switch, wherein a second diode is connected between the third switch and the neutral point. Two or more current transformers are arranged such that a drive signal is produced in an interleaved mode.

Abstract: A digital slope compensation apparatus and method for a switched-mode power supply use a sensor for sensing and generating an analog inductor current (iL) of the switched-mode power supply, a comparator (2) for generating a trigger signal according to a comparison of an analog current threshold level and the analog inductor current (iL), and a pulse width modulator (PWM) for controlling the operation of a switched-mode power supply, wherein the pulse width modulator (PWM) is arranged to be triggered by the trigger signal of the comparator. A first analog to digital converter is arranged for converting an analog output voltage (Vout) of the switched-mode power supply into a digital output voltage, means are arranged for transforming the digital output voltage into a digital current threshold level (icmp) and a digital to analog converter is arranged for generating the analog current threshold level according to the digital current threshold level (icmp).

Abstract: The invention relates to a power converter and a method for power conversion. A converter transformer with a primary winding and a secondary winding, an integrated current transformer and a synchronous rectifier are provided, wherein a controller is arranged in order to close respectively to open the synchronous rectifier depending on the measured winding current. The controller is arranged to close and/or to open the synchronous rectifier as a function of the winding current at a later and/or at an earlier time, whereby the time difference between the later and the earlier time is linearly dependent on the winding current difference, particularly in order to optimise a discharge process, and/or that an auxiliary supply circuit is arranged in order to provide auxiliary supply power, wherein the auxiliary supply circuit is arranged to derive auxiliary supply power from the integrated current transformer, in particular in overload situations.

Abstract: A winding assembly for a transformer includes a wire winding and a sheet winding. The wire winding includes a spirally wound insulated wire and the sheet winding includes a metallic winding sheet that forms a single turn winding. Instead of winding the wire winding on a bobbin, sleeve or the like, the wire winding is attached directly to a surface of the winding sheet by means of a self-bonding technique.

Abstract: An inductive element comprises at least two core-parts including a magnetically permeable material and at least one winding of an electrical conductor which can be a foil winding, a stranded wire (litz) winding or a conventional wire winding. Each core-part has an elongated center piece with an outer winding surface. At each of its longitudinal ends, the center piece has a contact element with a lateral contact surface. The winding is wound directly on the core-parts without a bobbin or the-like. The core-parts of the inductive element are arranged with their longitudinal axes essentially in parallel in a manner that the lateral contact surfaces of each contact element abut on a lateral contact surface of another core-part. Such an inductive element can be manufactured by co-axially arranging the core-parts and using them as a roll-shaft. After the windings have been applied to the core-parts, they can be rearranged, i.e. “flipped over,” in a stack-like arrangement in order to form an inductive element.

Abstract: A magnetic component, with a first and a second U/UR core (U1, U2) assembled to a first O-shaped core assembly, wherein an U/UR core has—according to its shape—a first post and a second post with free ends on one side and a leg connecting the first post and the second post on their other side, wherein the first and the second U/UR core (U1, U2) are assembled with their free ends abutting each other to form the first O-shaped core assembly. The free ends of a third U/UR core (U3) are abutting the outside of the first O-shaped core assembly on one side and that the free ends of a fourth U/UR core (U4) are abutting the outside of the first O-shaped core assembly on an opposite side. In another embodiment, the leg of a third U/UR core (U3) is abutting the outside of the first O-shaped core assembly, wherein the ends of a fourth U/UR core (U4) are abutting the ends of the third U/UR core (U3). In a further embodiment, the ends of a third U/UR core (U3) are abutting the outside of the first O-shaped core assembly.

Abstract: A DC-DC flyback converter that has a controlled synchronous rectifier in its secondary circuit, which is connected to the secondary winding of a main transformer. A main switch (typically a MOSFET) in the primary circuit of the converter is controlled by a first control signal that switches ON and OFF current to the primary winding of the main transformer. To prevent cross-conduction of the main switch and the synchronous rectifier, the synchronous rectifier is turned ON in dependence upon a signal derived from a secondary winding of the main transformer and is turned OFF in dependence up a signal derived from the first control signal. In one embodiment the first control signal is inverted and delivered to a logic circuit along with the voltage across the main transformer secondary winding and the voltage across the synchronous rectifier.

Abstract: A DC-DC switching converter device (101), in particular a quarter-brick or eighth-brick device having an industry standard pin out, comprises a pulse-width modulation circuit (132) for driving a power converting switch, a trim connector (109) for adjusting an output voltage of the device, where the device (101) is designed such that the pulse-width modulation circuit (132) is synchronizable to an external oscillator by an external synchronization signal applied to the trim connector. A DC-DC converting circuit comprises a plurality of DC-DC switching converters (101) featuring trim connectors (109) for adjusting output voltages of the converters (101), whereby the converters (101) are connected such that they share a common input bus. It further features a system EMI (electromagnetic interference) filter common to all the DC-DC switching converters (101) and an external oscillator delivering an external synchronization signal to the plurality of DC-DC switching converters (101).

Abstract: In a control circuit for powering up a switching power supply into a powered output bus, the control circuit is built such that before a turning-on of the switching power supply the controller reference is the slave that follows the bus voltage which is the master. At the moment when the converter is turned on, the master/slave relationship changes such that after the turning-on of the switching power supply the output voltage of the switching power supply is the slave that follows the controller reference. Hence, the status of the output level is memorized by the voltage loop prior to start-up of the converter such that the conflict between the soft-starting voltage loop of the converter and the pre-biased output is minimized.

Abstract: The configurations of a commutation failure detection circuit for a back-to-back SCR circuit and the controlling methods thereof are provided. The proposed commutation failure detection circuit includes a first detecting signal generator coupled to the back-to-back SCR circuit for detecting a commutation at a negative half cycle of an AC input voltage and including a first non-conductive signal amplifier circuit generating a first non-conductive signal when the back-to-back SCR circuit is not conductive at the negative half cycle of the AC input voltage and a second detecting signal generator coupled to the back-to-back SCR circuit for detecting the commutation at a positive half cycle of the AC input voltage and including a second non-conductive signal amplifier circuit generating a second non-conductive signal when the back-to-back SCR circuit is not conductive at the positive half cycle of the AC input voltage.

Abstract: The present invention is directed to a switch mode power converter for supplying an output power to a load, which includes a switching device having a switching input, a switching output, and a control input for enabling or disabling the switching device from conducting current from the switching input to the switching output. The converter also includes a network in which the switching device input, the switching device output, and the load are connected together to form a circuit. The converter also includes a bias winding in the circuit for producing a bias voltage representative of the output power, and a control circuit. The control circuit is for (a) determining the rate of change of the bias voltage, (b) characterizing the rate of change, and (c) controlling the control input as a result of the characterization (b).

Abstract: A magnetic device to be surface mounted on a substantially planar thermally conductive surface comprises a circuit board containing a winding pattern having at least one winding and a magnetic core that is at least partially encompassing the winding pattern. On a bottom side of the circuit board a region corresponding to a substantial part of the winding pattern is covered by a thermally conductive material for thermally contacting the thermally conductive surface. A transformer arrangement comprises such a magnetic device as well as a thermally clad circuit board having a surface area covered by a thermally conductive material, corresponding to at least substantially the covered region on the bottom side of the circuit board. For assembly, the covered region on the bottom side of the circuit board is soldered to the covered region on the surface of the thermally clad circuit board.

Abstract: DC-DC converters such as flyback converters achieve self-regulation by communication information between primary and secondary circuits through the power transformer. Operating in accordance with a generalized concept or algorithm, the converter can be bi-directional and self-regulating. Control of the turn OFF times of semiconductor switches in first and second circuits coupled to first and second windings of the power transformer determines whether power flow is in one direction through the converter or the other direction. Turn ON timing of each semiconductor switch is when there is a reverse current through the switch and voltage across the switch is at or near zero. Turn OFF of a switch can be controlled from one or more operating parameters of the converter such as output voltage, in which case the converter's self-regulation is affected through duty cycle variation with variations in output voltage.

Abstract: A coil form for forming an inductive element (10) includes a coil body (2) and at least one, for example three separating plates (3). The coil body (2) has an opening (4.1) and includes two portions, a coil portion (6) and a flange portion (7). To put the inductive element (10) together, the separating plates (3) are pushed over the coil portion (6) of the coil body (2). For positioning of the separating plates (3), recesses (8) are provided on the surface of the coil portion (6). The separating plates (3) divide the surface of the coil portion (2) into a plurality of coil areas where the coil or the coils of the inductive component (10) can be provided, for example by winding an isolated wire around the coil portion (6) in a coil area. Afterwards, the core of the inductive component is installed by fitting the two E-shaped core parts (11.1, 11.2) together such that the middle leg (13) of each core part (11.1, 11.2) is inserted into the opening (4.1) of the core body (2).

Abstract: The casing of a power supply includes a bottom and a cover. Both of them have a U-like shape. Since the cover is slightly wider than the bottom two air ducts are provided between the side plates of the bottom and the corresponding side plates of the cover respectively. A printed circuit board is mounted within the casing, particularly on the bottom. Different mechanical, electric and/or electronic components are mounted on the printed circuit board. Furthermore, heat generating components are mounted on the printed circuit board such that they are in right contact with the side plates of the bottom. The waste heat generated by the components is transferred to the side plates of the bottom and further on to the cover and its side plates. From there the heat is dissipated into the air and particularly into the air ducts from where it is dissipated by the air flow from two fans that are arranged at the inlet of the air ducts.

Abstract: An improved snubber is electrically switched to close a current path to a capacitor (C) in a series connected RC circuit at the onset of an abrupt voltage change otherwise producing ringing in a resonant circuit to which the snubber circuit is connected. The current path to the capacitor (C) is then interrupted before the capacitor (C) discharges and thereafter at each such voltage change in the resonant circuit the capacitor (C) is no longer charged from its totally discharged state but nevertheless damps the ringing by virtue of current flow to the nearly completely charged capacitor (C). By preventing complete charging and discharging of the capacitor (C) in the RC circuit every cycle, power dissipation in the resistance of the snubber circuit is greatly reduced.

Abstract: A DC-to-DC power adapter includes a first DC power input portion, a DC-to-DC power converting circuit and a first DC power output portion. The first DC power input portion is selectively connected to an AC-to-DC power adapter or a DC power connector for receiving a first input DC voltage from the AC-to-DC power adapter or a second input DC voltage from the DC power connector. The DC-to-DC power converting circuit is electrically connected to the first DC power input portion for converting the first input DC voltage or the second input DC voltage into a first DC output voltage. The first DC power output portion is electrically connected to the DC-to-DC power converting circuit for receiving and outputting the first DC output voltage.

Abstract: A low profile magnetic element used in cooperation with a multilayer printed circuit board has two or more core arms penetrating the board from one outer surface to the other and a series of magnetic core elements, at least one on each side of the board, bridging pairs of the core arms to form a closed, unbranched flux path. Series-connected windings form a transformer primary and are wound on the core arms that penetrate the board. Parallel-connected windings form a transformer secondary and are also wound on the core arms. The series-connected windings and the parallel-connected windings may be buried windings printed on internal surfaces of the multilayer board. The connected in series primary windings all have the same number of turns and the parallel-connected secondary windings all have the same number of turns. The parallel secondary windings are connected in current additive fashion to afford a high current transformer output.

Abstract: A coil form for forming an inductive element (10) includes a coil body (2) and at least one, for example three separating plates (3). The coil body (2) has an opening (4.1) and includes two portions, a coil portion (6) and a flange portion (7). To put the inductive element (10) together, the separating plates (3) are pushed over the coil portion (6) of the coil body (2). The separating plates (3) divide the surface of the coil portion (2) into a plurality of coil areas where the coil or the coils of the inductive component (10) can be provided, for example by winding an isolated wire around the coil portion (6) in a coil area. The separating plates are made of metal and form another coil of the inductive component. Afterwards, the core of the inductive component is installed by fitting the two E-shaped core parts (11.1, 11.2) together such that the middle leg (13) of each core part (11.1, 11.2) is inserted into the opening (4.1) of the core body (2).

Abstract: A DC/DC power supply with two transformers (10, 20), which for example are connected in parallel on the primary and in series on the secondary side, comprises two passive, non-dissipative snubber circuits (1.1, 1.2). Each snubber circuit comprises a series circuit formed by a capacitor (3.1, 3.2) and a diode (4.4, 4.7), which is connected to the output capacitor (13) of the power supply. The transformers are interleaved with a push-pull configuration. On the secondary side, the power supply has an output choke (12, 22) and two output rectifiers (11, 21) are connected to the secondary winding (14, 24) of each transformer. Each snubber circuit further comprises two additional diodes (4.5, 4.6, 4.8, 4.9), one electrode of these diodes being connected to the joint electrode of the snubber capacitor (3.1, 3.2) and the first snubber diode (4.4, 4.7) and the other electrodes being connected respectively to an end of the secondary winding (14, 24) of a transformer.