Abstract:
Es wird ein Sendeverstärker zum Verstärken eines Signals in einem drahtlosen Übertragungssystem vorgeschlagen. Der Sendeverstärker weist eine Vorverstärkerstufe und eine Verstärkerendstufe auf, die mit der Vorverstärkerstufe gekoppelt ist. Die Verstärkerendstufe ist aus Gatterbausteinen gebildet und ist dazu eingerichtet, ein eingespeistes Signal als verstärktes Ausgangssignal ausgangsseitig bereitzustellen. Durch die Verwendung von Gatterbausteinen kann ein kompakter und günstiger Sendeverstärker bereitgestellt werden, der einen Wirkungsgrad von ungefähr 90% aufweist.
Abstract:
A method for producing an output voltage to a load may include, in a power stage comprising power converter having a power inductor, a plurality of switches arranged to sequentially operate in a plurality of switch configurations, and an output for producing the output voltage comprising a first output terminal and a second output terminal, controlling the linear amplifier to transfer electrical energy from the input source of the power stage to the load in accordance with one or more least significant bits of a digital input signal, and controlling the power converter in accordance with bits of the digital input signal other than the one or more least significant bits to sequentially apply switch configurations from the plurality of switch configurations to selectively activate or deactivate each of the plurality of switches in order to transfer electrical energy from the input source of the power stage to the load.
Abstract:
A switching power stage for producing an output voltage to a load may include a power converter and a controller. The power converter may include a power inductor and plurality of switches arranged to sequentially operate in a plurality of switch configurations. The controller may be configured to, based at least on an input signal to the switching power stage, determine the differential output voltage to be driven at the load, and based on the differential output voltage to be driven at the load, apply a switch configuration from the plurality of switch configurations to selectively activate or deactivate each of the plurality of switches in order to generate the differential output voltage.
Abstract:
A multi-channel switchmode audio amplifier is configured by a programmed processor such that each channel drives separate loads, is connected in parallel or is configured in a bridge-tied mode as well as combinations thereof. In one embodiment, amplifier channels that are connected in parallel have power amplifiers that are driven with signals from a single modulator. A feedback circuit and error amplifier from one channel controls the modulated signal that is applied to each parallely connected amplifier channel. Current feedback circuits for parallely connected amplifier channels are eliminated by tightly controlling the timing of switching in the power amplifier output stages.
Abstract:
Unter den Verstärkerarten sind sogenannte Klasse-D-Verstärker bekannt, welche ein analoges Signal zunächst mit einem Pulsweitenmodulator in ein pulsweitenmoduliertes Schaltsignal umwandeln, das dann verstärkt und nachfolgend über einen Filter wieder in eine sich stetig veränderliche Spannung zurückgewandelt wird. Diese Art der Verstärker sind besonders energieeffizient und werden daher bevorzugt bei Verstärkern mit hohen Leistungen eingesetzt. Es wird eine Verstärkervorrichtung (1) mit einer Steuerungseinrichtung (5) vorgeschlagen, wobei die Steuerungseinrichtung (5) eine Eingangsschnittstelle für ein Audiosignal (2) aufweist, mit einer der Steuerungseinrichtung (5) nachgeschalteten Verstärkereinrichtung (9) zur Verstärkung des Audiosignals (2, 8), wobei die Steuerungseinrichtung (5) ein Verzögerungsmodul 6 aufweist, wobei das Verzögerungsmodul (6) ausgebildet ist, das Audiosignal (2) um einen Verzögerungswert delta_t verzögert an die Verstärkereinrichtung (9) weiterzugeben und in einer Anpassungsphase AP den Verzögerungswert delta_t automatisch und/oder selbsttätig von einem Startwert delta_t zu einem Endwert zu verringern.
Abstract:
A gradient coil power supply (100, 812) for a magnetic resonance imaging system (800) comprising: at least two H-bridge circuits (104, 106, 108, 200, 202, 204, 206); wherein the H-bridge circuits are connected in series; wherein each of the H-bridge circuits supplies voltage of a first polarity when in a first switching state (200); wherein the each H-bridge circuit supplies voltage of a second polarity when the H-bridge is in a second switching state (202); wherein each H-bridge circuit supplies no voltage when in a third switching state(204); wherein each H-bridge circuit supplies no voltage when in a fourth switching state (206); and a controller (814) for controlling the switching of the H-bridge circuits, wherein the controller is adapted for: - receiving (600, 700) a gradient pulse sequence (818), - creating (602, 702) a switching plan for controlling the switching of each of the H-bridge circuits, wherein the switching plan comprises controlling the voltage output of the gradient coil power supply by alternating between the first switching state and the second switching state, wherein the switching plan further comprises operating (710) at least one H- bridge circuit selected from the H-bridge circuits in either the third or fourth switching state for part of the switching plan to cool the H-bridge circuit, - executing (604, 704) the switching plan.
Abstract:
There is described a self oscillating modulator circuit comprising at least two coupled self oscillating loop modules, that achieved a good efficiency and a good linearity.
Abstract:
A driver (Highside Driver, Lowside Driver) adapted to drive each of final transistors (M H , M L , M power ) included in a power amplifier, the driver including: a first plurality of switches (M psiow , M pmoderate , M pfast ) having their respective main current channels coupled between a bias voltage terminal (V ddx ) and a control electrode of the respective final transistors (M H , M L , M power ), said first plurality of switches (M psiow , Mpmoderate, Mpfast) being selectively turned ON for enabling a progressive charging of the respective control electrode of the final transistors (M H , M L , M Power ), a second plurality of switches (M nsiow , M nfast ) having their respective main current channels coupled between another bias voltage terminal (V source ) and the control electrode of the respective final transistors (M H , M L , M power ), said second plurality of switches (M nsiow , M nfast ) being selectively switched ON until a current through the respective final transistors (M H , M L , M power ) changes its polarity.
Abstract translation:驱动器(Highside Driver,Lowside Driver),其适于驱动包括在一个或多个驱动器中的最终晶体管(M,H,M,L,M SUB) 功率放大器,所述驱动器包括:其各自的主电流通道耦合的第一组多个开关(MΩ,MΩ,MΩ,MΩ) 在偏置电压端子(Vddddx)之间和各个最终晶体管的控制电极(M H H,M L L,M N)之间, 功率<! - SIPO - >,所述第一组多个开关选择性地导通,以使得能够对最终晶体管的相应控制电极进行逐行充电(M&lt; 第二组多个开关(M N S N N N,M L),第二多个开关, SUB)),其各自的主电流通道耦合在另一个偏置电压端子(V SUB源极)和相应的最终晶体管的控制电极之间(M < ),所述第二多个开关(M SUB,N,N,N) 被选择性地导通,直到通过相应的最终晶体管(M H H,M L,M SUB)的电流改变其极性。
Abstract:
The invention relates to a switch mode power amplifier. A first and a second change-over switch are inserted between a DC voltage supply and a primary side of an isolation transformer. Two secondary windings are connected to a power output terminal. A first and a second secondary side power switch are adapted to connect the two secondary windings to the power connector of the power output terminal. The pulse width modulation means is adapted to generate control signals for the driver means of the first and the second change-over switch so as to cause every second pulse to be inverted. The pulse width modulation means is also adapted to generate a third and a fourth control signal for said driver means of the power switches of said first and said second secondary. The invention also relates to a method of controlling a switch mode power amplifier.