Abstract: A control device (8) for an inverter (2) that feeds an electric machine (3), wherein the control device (8) is configured to provide pulse-width modulated switching signals (15) for driving switching elements (12) of the inverter (2), wherein the control device (8) is configured to determine a modulation type by means of which the pulse-width modulated switching signals (15) are generated depending on operating point information that describes an operating point defined by at least one operating parameter, and to use a first modulation type in at least one first operating region (21, 28, 30, 31) and a second modulation type in another operating region (32, 32a, 32b).

Abstract: A control device (8) for an inverter (2) that feeds an electric machine (3), wherein the control device (8) is configured to provide pulse-width modulated switching signals (15) with a carrier frequency to drive switching elements (12) of the inverter (2), wherein the control device (8) is configured to determine the carrier frequency depending on operating point information that describes an operating point defined by a rotation speed and a torque of the electric machine (3) and, as the rotation speed increases and the magnitude of the torque falls, to increase the carrier frequency within an operating region (22) that extends within a rotation speed interval with a lower rotation speed limit (23) differing from zero and with an upper rotation speed limit (24) lying in a power-limiting operating region (21) or field-weakening operating region.

Abstract: A control device (8) for an inverter (2) that feeds an electric machine (3), wherein the control device (8) is configured to provide pulse-width-modulated switching signals (15) at a carrier frequency to drive switching elements (12) of the inverter (2), wherein the control device (8) is configured to ascertain the carrier frequency within at least one operating range (22, 23) depending on a piece of operating point information that describes an operating point defined by a rotation speed and a torque of the electric machine (3) in such a way that the carrier frequency is reduced within the at least one operating range (22, 23) compared to a maximum carrier frequency operating point at which a maximum carrier frequency is specified in the operating range.

Abstract: An EMI suppression component includes a piezoelectric element that is configured to provide a low impedance propagation path for electromagnetic disturbances at a resonance frequency of the piezoelectric element.

Abstract: A control device (8) for an inverter (2) that feeds an electric machine (3), wherein the control device (8) is configured to provide pulse-width modulated switching signals (15) for driving switching elements (12) of the inverter (2), wherein the control device (8) is configured to determine a modulation type by means of which the pulse-width modulated switching signals (15) are generated depending on operating point information that describes an operating point defined by at least one operating parameter, and to use a first modulation type in at least one first operating region (21, 28, 30, 31) and a second modulation type in another operating region (32, 32a, 32b).

Abstract: A control device (8) for an inverter (2) that feeds an electric machine (3), wherein the control device (8) is configured to provide pulse-width modulated switching signals (15) with a carrier frequency to drive switching elements (12) of the inverter (2), wherein the control device (8) is configured to determine the carrier frequency depending on operating point information that describes an operating point defined by a rotation speed and a torque of the electric machine (3) and, as the rotation speed increases and the magnitude of the torque falls, to increase the carrier frequency within an operating region (22) that extends within a rotation speed interval with a lower rotation speed limit (23) differing from zero and with an upper rotation speed limit (24) lying in a power-limiting operating region (21) or field-weakening operating region.

Abstract: A control device (8) for an inverter (2) that feeds an electric machine (3), wherein the control device (8) is configured to provide pulse-width-modulated switching signals (15) at a carrier frequency to drive switching elements (12) of the inverter (2), wherein the control device (8) is configured to ascertain the carrier frequency within at least one operating range (22, 23) depending on a piece of operating point information that describes an operating point defined by a rotation speed and a torque of the electric machine (3) in such a way that the carrier frequency is reduced within the at least one operating range (22, 23) compared to a maximum carrier frequency operating point at which a maximum carrier frequency is specified in the operating range.

Abstract: An EMI suppression component includes a piezoelectric element that is configured to provide a low impedance propagation path for electromagnetic disturbances at a resonance frequency of the piezoelectric element.

Abstract: The invention relates to a circuit for a system for contactless, inductive power transmission, in particular for use in supplying power to mobile devices, and to an associated charging circuit. The circuit comprises a primary-side circuit, which is disposed on a primary side and can be connected to a primary-side supply voltage, and a secondary-side circuit, which is disposed on a secondary side and can be connected to a load to be supplied with power. Furthermore a transformer stage having galvanic isolation is provided for the contactless transfer of power from the primary side over an air gap to the secondary side, wherein at least two magnetically coupled coils are provided for inductive power transmission and can be spatially separated from one another by distancing the secondary side from the primary side. The transformer stage has a resonant converter and the secondary-side circuit further comprises a restabilization stage.

Abstract: The invention relates to a circuit for a system for contactless, inductive power transmission, in particular for use in supplying power to mobile devices, and to an associated charging circuit. The circuit comprises a primary-side circuit, which is disposed on a primary side and can be connected to a primary-side supply voltage, and a secondary-side circuit, which is disposed on a secondary side and can be connected to a load to be supplied with power. Furthermore a transformer stage having galvanic isolation is provided for the contactless transfer of power from the primary side over an air gap to the secondary side, wherein at least two magnetically coupled coils are provided for inductive power transmission and can be spatially separated from one another by distancing the secondary side from the primary side. The transformer stage has a resonant converter and the secondary-side circuit further comprises a restabilisation stage.

Abstract: Conventional transformers with fractional turns have pre-manufactured cores usually with a complicated structure. According to the present invention, a method is provided of manufacturing a planar transformer where a ferrite polymer compound is laminated to a PCB for forming the core of the transformer. Advantageously, this may allow for the provision of a cheap and robust transformer.

Abstract: Recently, the use of class-D audio amplifiers has become more and more widespread. In contrast to the generally employed class-AB linear amplification technology, class-D allows for improved efficiency. However, the class-D principle is known for its poor distortion characteristics. According to the present invention a digital amplifier (18) is provided for converting an audio signal to a power output, comprising a ripple suppression circuit (16) for suppressing voltage ripples in a supply voltage supplied to the bridge circuit with (6) at least one pair of switches. The ripple suppression circuit (16) suppresses ripples in the supply voltage supplied to a switch in the bridge circuit (6), which has been found to cause a major part of the distortions in the output signal of the digital amplifier (18).

Abstract: A power converter comprising an inductor for receiving energy from a power supply, and connected to the inductor an output capacitor for providing an output voltage. In order to ensure a quick compensation of a reduction of load at the voltage output using few output capacitors, an additional current path is arranged in parallel either to the inductor or to the capacitor, which additional current path can be opened and closed. A current flowing through the additional current path reaches basically immediately a desired value, when the additional current path is opened. Feedback means are moreover provided for opening the additional current path, when the output voltage reaches a predetermined maximum value.

Abstract: Resonant gate driver circuits provide for efficient switching of, for example, a MOSFET. However, often an operation of the resonant gate driver circuit does not allow for an application where high switching frequencies are required. According to the present invention, a pre-charging of the inductor of the resonant gate driver circuit is performed. This allows for a highly efficient and fast operation of the MOSFETs.

Abstract: Since parallel MOSFETs are usually driven with one gate signal in power applications, the current sharing between the MOSFETs is automatically established with regard to the characteristics of the individual MOSFETs. This may lead to a large non-uniformity of the current distribution between the MOSFETs. According to the present invention, an individual control of the on-resistances of the MOSFETs is provided, which allows for an improved current sharing between paralleled MOSFETs.

Abstract: An MR apparatus has a resonant circuit, which is formed by an MR receiving coil (L1) and a capacitor (C1), and has an electronic control circuit (S) for switching the resonant circuit between two or more operating modes. The invention proposes that the electronic control circuit (S) be connected with a receiving device (L2) for wireless reception of a high-frequency electromagnetic control signal.

Abstract: The invention relates to an arrangement for converting mechanical energy into electrical energy comprising a piezo-electric auxiliary generator producing an auxiliary voltage and a main generator which is coupled mechanically with the auxiliary generator and producing the electrical energy.

Abstract: Usually, power supplies are not capable of switching off part of the outputs of a main power supply during stand-by. Due to this, stand-by power supplies are used in addition to operation power supplies. Consistent with an example embodiment, a forward converter is provided, including switches in the rectifier circuit thereof. Due to this, the rectifier circuits may be selectively switched on and off. Advantageously, this may allow that the main outputs of such a forward converter are switched off while on stand-by.

Abstract: Since parallel MOSFETs are usually driven with one gate signal in power applications, the current sharing between the MOSFETs is automatically established with regard to the characteristics of the individual MOSFETs. This may lead to a large non-uniformity of the current distribution between the MOSFETs. According to the present invention, an individual control of the on-resistances of the MOSFETs is provided, which allows for an improved current sharing between paralleled MOSFETs.

Abstract: Power conversion circuits often consist of several MOSFETs operating in parallel. Due to thermal cycling and mechanical operations. MOSFETs or the respective electric connections of the MOSFETs may fail. For certain implementations, a diagnosis circuit for a plurality of parallel MOSFETs predicts or determines a possible failure on the basis of at least one of temperatures of the MOSFETs or gate voltages of the MOSFETs. In some applications, the MOSFETs are monitored to facilitate early determination of failures of the MOSFETs.