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: 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: 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: 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: It is proposed that passive wireless transponder systems used in the context of procedures for access identification be provided with signaling that can be perceived by human beings. This also makes it possible to detect that a relay attack, which is difficult to prevent, is being carried out. Attention is also drawn to other types of manipulative interference with the communication and to certain problems with the high-frequency transmission. By the employment of comparatively inexpensive and highly reliable means, this near-simultaneous perception of an identifying process for access purposes produces a very effective reduction in such threats to the security of the system. Other simple measures may have an advantageous effect in connection therewith. The signaling may also assist an ergonomic process. For example, an automobile entry or access system that is not specifically actuated, referred to as a passive keyless entry system, may be improved.

Abstract: The invention relates to a circuit arrangement for an MR apparatus, having a resonant circuit, which is formed by an MR receiving coil (L1) and a capacitor (C1), and having 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: 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 die bridge circuit with (6) at least one pair of switches. The ripple suppression circuit (16) suppresses ripples in die 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: 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. According to the present invention, 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: 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. According to the present invention, there is provided a diagnosis circuit for a plurality of parallel MOSFETs, which predicts or determines a possible failure on the basis of at least one of temperatures of the MOSFETs or gate voltages of the MOSFETs. Advantageously, a continuous monitoring of the MOSFETs may be provided and an early determination of failures of the MOSFETs can be provided.

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: Resonant gate driver circuits provide for an 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 drive circuit is performed. This allows for a highly energy efficient and fast operation of the MOSFET.

Abstract: The trend towards more digital signal processing in mains-powered devices causes an increasing variety of supply voltages at ever decreasing levels and at higher currents. At present, the secondary side architecture provides a separate ac-dc conversion and dc-dc down-conversion stages in order to obtain stabilized voltages at those low levels. According to the present invention, a controlling synchronous rectifier is provided, comprising a power MOSFET and a control unit which allow to integrate both stages. In particular, according to the present invention, the output voltage of the synchronous rectifier is controlled by controlling the channel switching of the MOSFET. Advantageously, this provides for a very simple and efficient rectification and voltage control.

Abstract: At The invention relates to a DC/DC down converter which includes a synchronous rectifier, a switching element at its input side and an inductance at its output side. In order to permit fast load fluctuations as well as to reduce costs and operating losses, it is proposed to provide an auxiliary circuit which comprises an auxiliary switching element, an auxiliary rectifier and an auxiliary inductance, the auxiliary circuit being coupled to the connection between the synchronous rectifier, the switching element at the input side and the inductance at the output side.

Abstract: A control unit (2) of a remote control receiver sets the forward or reverse direction operating mode of the photodiode (1) as a function of the useful signal level of its output signal, and to be precise, during standby, the photovoltaic operating mode (forward mode), since in this mode no external bias current is required. If the useful signal level of the photodiode (1) exceeds a predefined threshold, the reverse mode is set, and this brings with it a higher sensitivity. A series circuit (A) of a number of identical photodiodes DA1 DAn in the forward mode allows the realization of a controlled current source (6) having a transistor (T), since the permissible diode voltage (Ud) of the overall arrangement may have n times the value of the operating voltage of an individual photodiode. Thus at the same time the voltage across the individual diodes can be set to a very low value and a favorable operating range for the current source can be set.

Abstract: A method for controlling the transient response of a power converter powering a load, said power converter comprising a power switch, a synchronous rectifier and a capacitor coupled between an input and an output of the power converter, said method comprising the step of—disabling said synchronous rectifier in response to a signal indicative of a change of said load, is characterized by—providing said signal based on a current representing said change of load.

Abstract: The invention relates to a power converter comprising an inductor 6 for receiving energy from a power supply 1, and connected to the inductor 6 an output capacitor 7 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, it is proposed that an additional current path 11,12 is arranged in parallel either to the inductor 6 or to the capacitor 7, which additional current path 11,12 can be opened and closed. A current flowing through the additional current path 11,12 reaches basically immediately a desired value, when the additional current path 11,12 is opened. Feedback means are moreover provided for opening the additional current path 11,12, when the output voltage reaches a predetermined maximum value. The invention relates equally to a corresponding method.

Abstract: The invention relates to a device which comprises a circuit arrangement and at least one inductive element. In order to form a device with a circuit arrangement with one or more inductive elements which can be manufactured as economically as possible, it is proposed to use an electrically conductive plate (13) having an inductive function, the inductive function corresponding to a structure of slits (20a, 20b, 20c) formed in the plate.

Abstract: In known converter circuits switching losses occur, which are caused by reverse-recovery currents of a freewheeling diode. To reduce said switching losses it is proposed by the invention to drive the switching elements such that, upon switching from the second to the first switching element, the timing is controlled in such a manner that the shoot through currents and the conduction of the freewheeling diode are kept at a low value or, better still, are precluded. As regards the control mechanism, it is proposed to turn on the first switching element later if shoot through currents occur, and to turn on the first switching element sooner if conduction of the freewheeling diode occurs. Here, a time of overlap may be provided during which both switching elements are simultaneously conducting. For the control mechanism, the voltage across a switching element can be used as a measured input value.