Koninklijke Philips Corporation N.V.

U.S. Philips Corporation

Bobinados De Transformadores S.l.

Pieter Jan Mark Smidt

Thomas Duerbaum

Tobias Georg Tolle

Hendrikus Johannes Jacobus Domensino

Rudi Jonkman

Jorge Luiz Duarte

Thomas D&uuml;rbaum

Robert Eduard Fransiscus Einerhand

Fatmir Ribari

A switch mode power supply for feeding a single ended class D amplifier, having. two voltage sources () is disclosed. The power supply comprises a voltage equalizer circuit including a coil () having a first terminal connected to said common point (), a first switch () connected between a second terminal of the coil () and the positive side of the first source (), a second switch () connected between said second terminal of the coil () and the negative side of the second source (), and control circuitry () for determining when the voltage (v, v) of one of the voltage sources (or) exceeds a predetermined threshold value (vthresh,ON), and, in response to such a determination, periodically operate the switch (or) associated with said one voltage source ON and OFF, thereby redistributing energy from said one voltage source (or) to the other voltage source (or). The inventive voltage equalizer thus acts as a switch mode converter, redistributing energy from one voltage source to the other, thereby ensuring that the output voltages of both sources are essentially equal. Further, the voltage equalizer requires very few components, and is thus simple to implement. As the two switches only need to handle the excess of power they can be relatively small and cost efficient.

Switch mode power supply with output voltage equalizer

The present invention relates to a bidirectional flyback switch mode power supply (SMPS), such as a bidirectional flyback converter, and a method for operating it. The SMPS comprises a transformer having primary and secondary windings inductively coupled together, said primary winding being coupled to a voltage input of the converter and said secondary winding being coupled to a voltage output of the converter; a primary control unit comprising a primary switch arranged in series with the primary winding and a secondary control unit comprising a secondary switch arranged in series with the secondary winding. The primary control unit is adapted to compensate input voltage variations, and the secondary control unit is adapted to provide a controlled output power on the secondary side.

Bidirectional flyback switch mode power supply (SMPS)

The invention relates to a transformer () with a core () which has a center piece () with a first and a second flange (), in which a first and a second winding () of the transformer () are wound on the center piece (). To produce a transformer as compact as possible which allows simple adaptation to limit leakage currents, it is proposed that the winding end pieces () of the first winding () guided out of the winding body are guided through at least one recess in the first flange () and that winding end pieces () of the second winding () guided out of the winding body are provided which form at least partly loose line ends. Alternatively, the winding end pieces () of the first winding () guided out of the winding body are guided immediately about the edge of the first flange () and connected with connecting elements () which are arranged on the side of the first flange () opposite the center piece ().

Transformer

An amplification device is disclosed providing a way of integrating a switch mode power supply and a class D amplifier (switch mode amplifier). This results in the usage of basically one magnetic component (), one major energy storage element () and switches () that are controlled in such a way that both the power supply function and the amplification function are achieved. In this way a cheap, small and highly efficient current configuration is achieved. This amplification device is especially useful in audio products.

Isolated converter with synchronized switching leg

An electrical circuit arrangement provides a low power rectified low voltage from an AC line voltage. The circuit consists of two circuit blocks combined together via an intermediate circuit, of which the first circuit block contains a capacitive input stage for producing a voltage-limited intermediate voltage that is substantially less than the line voltage, and a second circuit block that contains an asymmetric half-bridge that receives the intermediate voltage and produces an AC voltage that is decoupled from the line voltage via a transformer that is operated at the substantially lower voltage. The output of the transformer is rectified to provide the low-level DC output.

Low-power low-voltage power supply

According to one example embodiment, a power-supply system describing a bi-directional flyback topology includes two flyback converters working in opposite directions. Current flowing from a power supply unit to an apparatus is converted from a mains input in the power supply unit to a rectified output current fed to the apparatus via a two-lead cable. In the opposite direction, a secondary control circuit, situated in the apparatus, including a secondary switch causes excess current to be fed back to the power-supply unit where primary control circuitry reacts to stabilize the current fed to the apparatus. The primary control circuitry serves to minimize the amount of energy received from the feedback. The excess current in the apparatus is determined by monitoring the voltage and the current in the apparatus is load. If the measured parameters are too high, transfer of more energy back to the power-supply unit will be performed.

Power supply system with secondary control circuitry providing power-based feedback

A buck converter, boost converter or flyback converter is generally represented as a two-port having a primary side with a primary switching device ( ), and a secondary side with a secondary switching device ( ). The primary switching device is controlled in such a way that the on-time is adapted to the voltage at the primary side of the converter. The relation between the on-time of the primary switching device and the primary voltage is a generally hyperbolic function.

Bidirectional converter with input voltage control by a primary switch and output voltage regulation by a secondary switch

A multimode switched-mode power supply operates in a first control mode when the output power supplied is lower than a predetermined value, and in a second control mode when the output power supplied is higher than said predetermined value. The switched-mode power supply comprises a series arrangement of a switch (S ) and an inductor (L; Lp), the series arrangement being coupled to receive a DC input voltage (Vin). A control circuit (CC) controls the on and/or off times of the switch (S ) to generate a periodical inductor current (Ip) in the inductor (L; Lp). In the first control mode, a peak value of the inductor current (Ip) is substantially constant, independent of the power supplied. The substantially constant peak value is substantially equal to a peak value of the inductor current (Ip) at an instant when the second control mode is altered into the first control mode.

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Eindhoven, Netherlands

Pieter Jan Mark Smidt