U.S. Philips Corporation

Koninklijke Philips Corporation N.V.

Hubert C Raets

Manfred Albach

Thomas Duerbaum

Reinhold Elferich

Carsten Deppe

Eberhard Waffenschmidt

Dirk Hente

Georg Sauerlaender

Ulrich Boeke

Pawel M Gradzki

Armin F Wegener

Jan Zwier

Theo Husgen

Gerd Schiefer

Thomas D&uuml;rbaum

Ulrich B&ouml;ke

Johannes A A Wijntjes

Georg Sauerl&auml;nder

A resonant converter includes an inverter for generating an AC voltage which is fed to a resonant arrangement with a capacitor and a transformer. The circuit provides two types of secondary units, each having a secondary winding of the transformer and at least one rectifier element. Secondary units of the first and second type are then distinguished by opposite orientation. At least two output voltages are delivered on the output, a first output voltage of which being supplied as a direct output of a first-type secondary unit and a second output voltage as a &ldquo;stack output&rdquo; of a first-type secondary unit and a second-type secondary unit. The two output voltages can be regulated separately and independently of each other with a regulating device by suitably choosing frequency and duty cycle of a pulse width modulated voltage generated by the inverter driven by the regulating device.

Regulating device for a resonant converter

The invention relates to a DC&mdash;DC converter and a power supply unit formed thereby, with which a DC input voltage (V ) may be converted into two DC output voltages (U Usb) via a resonant switched-mode power supply. Via a circuit stage (M M ), a control circuit (C) generates a first AC voltage (V ), which is converted via two resonant circuits with different transmission behavior and two rectifiers (G Gsb) in frequency-dependent manner into DC output voltages (U1, Usb). To achieve a standby mode, in which the first DC output voltage (U ) is designed to be very low and hardly any power is drawn on the output side, a second, thinner auxiliary circuit stage (M M ) is provided, which is coupled to the resonant circuits via an inductor (L ). The current consumption of the circuit in standby mode may be reduced considerably by appropriate dimensioning.

DC-DC converter with switchable control mode

A switched-mode power supply includes at least one capacitor ( ) and a transformer having a plurality of windings ( ). Advantageously a capacitor ( ) is integrated in the transformer by way of at least one multi-layer foil winding ( ). This foil winding ( ) of the transformer consists of a plurality of planar conductive electrodes ( ) which, alternately with an insulating dielectric foil, are stacked onto each other to form an electrode stack.

Capacitor integrated into transformer by multi-layer foil winding

A circuit arrangement for supplying a lamp with a DC lamp current and comprising only passive components and equipped with mains input terminals for connection to the poles of an AC supply voltage source. A rectifying apparatus has two input terminals coupled to the mains input terminals and two output terminals for generating a DC voltage from the low frequency AC supply voltage. A ballast capacitor is coupled between the mains input terminals and the output terminals of the rectifying apparatus. A load circuit is coupled to the output terminals of the rectifying apparatus and has terminals for connection to the lamp. The load circuit includes a series arrangement of only passive components which connect the output terminals of the rectifying apparatus and comprise an inductor and the terminals for connection to the lamp. The circuit arrangement is simple and inexpensive and is very suitable for operating a discharge lamp and for incorporation into a compact lamp.

Discharge lamp DC ballast employing only passive components

A DC to DC converter converts a DC input voltage into a plurality of DC output voltages and includes a circuit stage having switching elements for converting a DC input voltage into a first AC signal (V ). A first resonant circuit converts a first AC signal into a second AC signal which is used for forming a first DC output voltage. A second resonant circuit converts the first AC signal into a third AC signal which is used for forming a second DC output voltage. A control circuit sets various frequency ranges for the first AC signal to set various supply power modes, such as for normal operation and standby mode.

DC to DC converter

A converter includes circuit elements for chopping a DC voltage, in which switch-on phases of the circuit elements are alternating. A circuit assembly with resonant elements is used for processing the chopped DC voltage and for producing an output voltage. The voltage present at one of the circuit elements is compared with a threshold in a dead time phase before the circuit element is switched on. The comparison result is used to determine whether an inductive or capacitive converter load is present. Alternatively, a differential quotient of the voltage present at one of the circuit elements during the dead time phase is used to determine whether an inductive or capacitive converter load is present.

Converter with resonant circuit elements for determing load type

The invention relates to a converter comprising switching elements for chopping a direct voltage, in which turn-on phases of the switching elements alternate with one another, and comprising a circuit arrangement with resonant circuit elements processing the chopped direct voltage and serving for the supply of an output voltage. To improve such a converter in such a way that zero voltage switching (ZVS) can be ensured in an extended range of converter operations with possibly inexpensive converter modifications, it is proposed that the length of the dead-time phases, which are present between two consecutive turn-on phases and during which the switching elements are turned off, is automatically adapted so that switching losses, which occur particularly when the switching elements are turned on, can be minimized.

Converter comprising resonant circuit elements

A high-voltage generator includes a high-voltage unit (,) and a further voltage generating unit (,) for generating DC high voltages (U,, U,), the voltage generating unit (,) including an adjustment unit (,) for adjusting a DC high-voltage (U,, U,) in an adjusting range between a lower and an upper limit voltage. In order to enable an as low as possible electric strength of the adjustment unit (,) and to reduce the impedance of the voltage generating unit (,), a DC voltage of between 100% and 200% of the upper limit voltage is applied to one connection point of the adjustment unit (,) whereas a DC voltage of between 50% and 100% of the lower limit voltage is applied to the other connection point of the adjustment unit (,).

High-voltage generator including a high-voltage unit

A transformer, particularly for a voltage converter, has a primary winding having a predeterminable leakage inductance and at least one secondary winding magnetically coupled to the primary winding with a predetermined voltage-transformation ratio. The (primary) leakage inductance is increased as compared with a conventional transformer without violating the limits for implementing an appropriately functioning transformer, and without choosing an additional coil or a larger core than is required for the power transformation, in that the primary winding comprises at least two winding sections whose magnetic couplings to the at least one secondary winding are implemented such that they operate in mutually opposite senses and are arranged such that they are at least substantially magnetically decoupled from one another.

High leakage inductance transformer

A voltage converter for converting an input voltage into at least a first high output voltage and a second lower output voltage. An input resonant circuit includes a transformer primary winding. At least first and second output circuits, each of which includes a respective secondary winding or a part of a secondary winding of the transformer and which supply the first and second output voltages. The second output circuit includes a rectifier arrangement supplying a DC output voltage. To improve the synchronism of the output voltages, i.e. reduce the cross-regulation, an additional capacitance is connected parallel to the secondary winding of the second output circuit and is dimensioned such that its capacitance, transformed to the primary winding essentially corresponds to the capacitance, transformed to the primary winding, of a parallel capacitance of the secondary winding of the first output circuit. Alternatively, a subsidiary circuit can be added to the second output circuit comprising an additional transformer secondary winding with an additional capacitor and an additional rectifier arrangement in a series circuit arranged parallel to a branch of the rectifier arrangement and to a load connected thereto.

Multiple output voltage converter with improved cross-regulation

In a voltage converter for converting an AC input voltage into a DC high voltage and further DC power supply voltages, in which the AC voltage applied to the converter is applied to a rectifier arrangement (1, 2, 3, 4) whose output signal is coupled to two consecutively switched electronic switches (6, 7), and in which this DC voltage is converted into the DC high voltage and into the DC power supply voltages, the circuit arrangement has a simple structure in that a series arrangement of a capacitance (8), an inductance (9) and a primary winding (10) of a transformer (11) is arranged in parallel with one of the electronic switches (6, 7), in that a secondary winding (12) of the transformer (11) precedes a capacitance (15) at the output end, in that a control circuit (20) is provided which controls the switching frequency of the electronic switches (6, 7) in such a way that a DC voltage of the desired value decreases across the capacitance (15) at the output end, and in that the transformer (11) is provided with additional taps (16, 17) at the secondary end, from which the DC power supply voltages can be derived.

Voltage converter

A circuit arrangement including an EHT cascade circuit (1) with at least a series arrangement (2, 3) of capacitors having staggered conductive strips (19, 20, 21, 22, 23, 24, 25) provided on both sides of a dielectric layer (18, 18a, 18b) which, together with the conductive strips (19, 20, 21, 22, 23, 24, 25), is wound about a support to constitute a winding form (15, 15a, 15b). A compact and low-cost construction, particularly for use of the circuit arrangement in an EHT generator for a picture display tube, is achieved in that the EHT cascade circuit (1) precedes an EHT output capacitor (6, 12), and in that the EHT output capacitor (6, 12) is the support.

Circuit arrangement including an EHT cascade circuit

A simple circuit arrangement for supplying a load (10) with energy from a power supply means (1 to 5) ensures both a uniform energy supply of the load and a reliable suppression of interference, both from the load into the power supply mains and in the reverse direction. The circuit accomplishes the foregoing by utilizing at least two energy storage devices (7, 9), at least one of which can be alternately connected either to the load or to the power supply mains (1 to 5).

Circuit arrangement for supplying a load

A circuit arrangement for supplying a load (15) with energy from a power supply mains (1 to 5; 21, 22, 23) conveying at least one alternating voltage (UW; R, S, T) includes a simple network to ensure both a uniform energy supply of the load (15) and a reliable suppression of interference from the load to the power supply mains and in the reverse direction by means of a rectifier arrangement (7 to 10) which for each terminal (4, 5; 21, 22, 23), of the power supply mains includes a rectifier stage (7, 8; 9, 10; 24, 25; 26, 27; 28, 29) constituted as a first branch of a bridge rectifier. For each rectifier stage an energy storage device (11; 12; 30; 31; 32) can be charged by and is connected to said stage in accordance with a complementary branch of the bridge rectifier. For each stage a switching element (13; 14; 33; 34; 35) is provided for connecting each energy storage device to the load. A control circuit (18; 36; 191, 192) switches the switching elements-- cyclically following the charge of the energy storage devices from the power supply mains, via the rectifier stages. The switching elements are switched to conduct outside of the charge time intervals of the storage devices (i.e. the conducting phases of the rectifier stages).

A circuit arrangement for feeding a load (3) from a low voltage energy source (1) via a direct-voltage conversion circuit (2). The direct-voltage conversion circuit periodically takes energy from the energy source by means of a main switching element (10) and supplies this energy as an increased supply voltage (at 12) to the load via an inductive element (9) and a rectifier (11). A starting switching element (15) takes energy for generating the supply voltage (at 12) from the energy source during a starting phase. The circuit arrangement is simple and compact and the energy losses produced are so low that it is economic to use it for energizing a small appliance particularly a small domestic appliance, from a battery or a rechargeable accumulator. A main control circuit (13) is supplied with energy directly from the supply voltage (at 12) and periodically controls the main switching element. A starting control circuit (16) is fed directly and exclusively from the energy source and periodically controls the starting switching element (15) so that is switching periods are shorter than those of the main switching. The starting control circuit, and thus the starting switching element, are switched off when the supply voltage reaches a predetermined value.

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Nieuwenhagen, Netherlands

Hubert C Raets