Abstract: A topology of bi-directional multi-output multi-function converter is designed in a BBU. The concept of bi-directional multi-function multi-output converter may be designed for the application of BBUs in a data center to provide multiple control functionalizes, such as battery discharging, battery charging, fan speed control, pump control, as well as providing power for multiple components/devices simultaneously. The proposed converter has two characteristics: bi-direction and multi-output. With the function of bi-direction, the battery discharging and charging can be accomplished with the same converter. With the function of multi-output, different rails of output voltages or power can be applied to different components or devices in BBU, such as fan, pump, control IC chip, sensors and etc.

Abstract: Disclosed is a power calculation method of a magnetic circuit. In view of the power problem of a magnetic circuit and the phase problem of a magnetomotive force (MMF) and a magnetic flux in the magnetic circuit, the present disclosure draws a magnetic circuit vector diagram based on an equivalent magnetic circuit vector model, and provides a method for calculating virtual magnetic active power, virtual magnetic reactive power, and virtual magnetic complex power of the magnetic circuit by analyzing the MMF, the magnetic flux, the reluctance, and the magnetic reactance in the magnetic circuit by using the magnetic circuit vector diagram.

Abstract: A wide input voltage range power converter circuit in a one-stage-two-switch configuration has a power input terminal, a switch node connected to the power input terminal, a transformer, two electronic switches, a pulse width modulation (PWM) circuit, and an output circuit. An input side of the transformer has a first winding and a second winding that are connected to the switch node. An output side of the transformer has an output winding. A turns ratio between the first winding and the output winding is different from a turns ratio between the second winding and the output winding. The two electronic switches are respectively connected to the first winding and the second winding in series. The PWM circuit is connected to the power input terminal and control terminals of the two electronic switches. The output circuit is connected to the output winding.

Abstract: An apparatus for modular AC to AC frequency conversion is disclosed. An input AC source is configured to generate an input AC voltage at a first frequency. At least one primary low frequency (LF) conversion stage is configured to generate a DC voltage, and comprises a first pair of metal-oxide-semiconductor field effect transistors (MOSFETs). At least one primary high frequency (HF) conversion stage is configured to generate the DC voltage, and comprises a first pair of high electron mobility transistors (HEMTs). At least one secondary LF conversion stage is configured to receive the DC voltage and generate an output AC voltage at a second frequency, and comprises a second pair of MOSFETs. At least one secondary HF conversion stage is configured to receive the DC voltage and generate the output AC voltage at the second frequency, and comprises a second pair of HEMTs.

Abstract: A system for load balancing on a multi-phase power line connected to a single phase lateral power line, includes a contactor configured to selectively connect each phase of the multi-phase power line to the single phase lateral power line. There is a phase change device connected in parallel with the contactor and a controller. During the phase change state, the controller connects the input of the phase change device to the multi-phase power line and connects the output of the phase change device the single phase lateral power line. The controller causes the phase change device to output a voltage to the single phase lateral line initially aligned with the first phase and then rotated to align with the second phase and causes the contactor changes connection to the second phase of the multi-phase power line and disconnect the phase change device from the power lines.

Abstract: A power transmitter includes a control and communications unit, an inverter circuit, a coil, and a shielding. The control and communications unit is configured to provide power control signals to control a power level of a power signal configured for transmission to a power receiver, provide a power timing request to an external power supply, and determine if the timing of the external power supply is compliant if the power timing request is met within a timing interval. The coil is configured to transmit the power signal to a power receiver, the coil formed of wound Litz wire and including at least one layer, the coil defining, at least, a top face. The shielding comprises a ferrite core and defining a cavity, the cavity configured such that the ferrite core substantially surrounds all but the top face of the coil.

Abstract: A power transmitter includes a control and communications unit, an inverter circuit, a coil, and a shielding. The control and communications unit is configured to provide power control signals to control a power level of a power signal configured for transmission to a power receiver, provide a power timing request to an external power supply, and determine if the timing of the external power supply is compliant if the power timing request is met within a timing interval. The coil is configured to transmit the power signal to a power receiver, the coil formed of wound Litz wire and including at least one layer, the coil defining, at least, a top face. The shielding comprises a ferrite core and defining a cavity, the cavity configured such that the ferrite core substantially surrounds all but the top face of the coil.

Abstract: A control circuit and a method for controlling a piezoelectric transformer are disclosed. In an embodiment the control circuit includes an inductor and a control unit, wherein the control circuit is configured to apply a voltage with a periodic waveform to a piezoelectric transformer, wherein a period duration of the voltage is specified by a control frequency and adjust the control frequency of the applied voltage as a function of an average current intensity of a current flowing through the inductor.

Abstract: Techniques for providing vertical integrations of semiconductor chips, magnetic chips, and lead frames. The techniques can include fabricating an integrated circuit (IC) device as a multi-layer IC structure that includes, within a sealed protective enclosure, a first layer including at least one magnetic chip, a second layer including at least one semiconductor chip or die, and a lead frame. The techniques can further include vertically bonding the magnetic chip in the first layer onto the topside of the lead frame, and vertically bonding the semiconductor chip or die in the second layer on top of the magnetic chip to form a multi-layer IC structure.

Abstract: A method for forming a component includes providing a first layer of a mixture of first and second powders. The method includes determining the frequency of an alternating magnetic field to induce eddy currents sufficient to bulk heat only one of the first and second powders. The alternating magnetic field is applied at the determined frequency to a portion of the first layer of the mixture using a flux concentrator. Exposure to the magnetic field changes the phase of at least a portion of the first powder to liquid. The liquid portion couples to at least some of the second powder and subsequently solidifies to provide a composite component.

Abstract: An apparatus can include a processor; memory accessible by the processor; a display operatively coupled to the processor; a hinge assembly that includes an axle and leaves where at least one of the leaves includes a leaf magnet that includes north poles and south poles; and a first housing and a second housing that include leaf receptacles that, in a coupled state, receive the leaves of the hinge assembly to pivotably couple the first housing and the second housing.

Abstract: An intelligent electronic device (IED) may obtain a residual flux of each phase of a transformer. The IED may determine a maximum difference (DIF) signal based on the residual flux and the prospective flux associated with potential close POWs of the corresponding phase. The TED may select a closing POW that results in a minimum DIF signal. The TED may send a signal to close a ganged switching device of the transformer at a time based on the selected closing POW.

Abstract: Unique systems, methods, techniques and apparatuses for a ZVT ZCT resonant converter with a variable resonant tank are disclosed. One exemplary embodiment is a system comprising a bidirectional resonant converter comprising an input/output terminal, a switching device coupled with the input/output terminal, a resonant circuit coupled with the switching device and including a variable inductor, an output/input terminal coupled with the resonant circuit, and a DC biasing circuit operatively coupled with the variable inductor. The variable inductor comprises a toroidal core, a first winding wound around the toroidal core and coupled with the switching device and the output/input terminal, a second core structured to overlap a portion of the toroidal core, and a second winding wound around the second core and coupled with the DC biasing circuit. The DC biasing circuit is controllable to vary the inductance of the variable inductor by saturating a portion of the toroidal core.

Abstract: A calibration device includes a controller configured to communicate a plurality of input voltage signals having different determined frequencies to a first power exchange coil. Also, the calibration device includes a load unit coupled to a second power exchange coil, where the load unit includes at least a first electrical load and a second electrical load. Further, the calibration device includes a voltage sensor configured to measure a plurality of first output voltage signals across the first electrical load and a plurality of second output voltage signals across the second electrical load, and where the controller is configured to determine an optimal operating frequency of a wireless power transfer system based on the plurality of input voltage signals, the plurality of first output voltage signals, and the plurality of second output voltage signals.

Abstract: The invention relates to the antenna technology used generally for providing a communication in the mines, in particular to the small resonant re-tunable antennas intended for providing an induction communication too. The technical effect is a possibility to adjust smoothly an operation frequency of the antenna within the wide radio wave range and, as a consequence, a possibility to compensate an effect of the outer objects having a capacity and switch the antenna to the other transceiving frequency channels.

Abstract: Embodiments may relate to a radio frequency (RF) front-end module (FEM) with a first filter and a second filter. The RF FEM may include a termination inductor coupled to ground, and a switch that is to selectively couple the first filter and the second filter to the termination inductor. Other embodiments may be described or claimed.

Abstract: A lighting driver (600, 800, 900) receives an AC Mains voltage (15), employs a rectifier (630, 830, 930) to produce a rectified voltage, and supplies an output current (665) to a lighting device (20) in response to the rectified voltage. A surge protection circuit (840, 940) of the lighting driver includes a voltage clamping device (MOV2) connected across the output of the rectifier, and a differentiator circuit (843/845/847/849, 943/945/947/949) configured to differentiate between a temporary voltage spike at the input to the rectifier and a loss of neutral connection to the lighting driver. When a temporary voltage spike is detected, the voltage clamping device is activated to clamp the rectified voltage until the temporary voltage spike ends. When a loss of neutral is detected, the voltage clamping device is latched into a disabled state until the AC Mains voltage input to the lighting driver is turned off.

Abstract: A power transmission device includes a communication unit that transmits a power capability information transmission request via a communication channel and receives power capability information in response to the power capability information transmission request. The power transmission device also includes a processing unit that sets a parameter based on the power capability information. Further, the power transmission device includes a power transmission unit that wirelessly transmits power using the parameter. The communication unit transmits the power capability information transmission request before the power transmission unit wirelessly transmits the power.

Abstract: A coil sheet includes a conductor layer, a thermally resistant organic insulating layer, a thermosetting adhesive layer in a B-stage state, and a base layer, such that the conductor layer and the insulating layer are bonded to the base layer with the adhesive layer. A coil is formed of a laminate sheet including a conductor layer, an insulating layer, and an adhesive layer of the coil sheet which are released from the base layer thereof, wherein the laminate sheet is wound around a specific axis a plurality of times, and the adhesive layer is thermally cured.

Abstract: A power converter including: a first branch and a second branch of at least two series-connected switches each, coupled in parallel between a first terminal and a second terminal and having the junction points of their switches coupled to two terminals of application of a first voltage; a third branch and a fourth branch of at least two series-connected switches each, coupled in parallel between a third terminal and a fourth terminal, and having the junction points of their switches coupled to two terminals for supplying a second voltage; and at least one piezoelectric element coupling the first terminal to the third terminal.

Abstract: Disclosed herein is a common mode filter that includes a winding core part including first to third winding areas and first and second wires wound in a same direction around the winding core part and crossing each other in the third winding area. The first wire is aligned and wound in the first and second winding areas, and the second wire is aligned and wound on the first wire in the first and second winding areas, whereby a plurality of winding blocks are formed. The winding blocks include a first winding block positioned in the first winding area and second and third winding blocks positioned in the second winding area. The second wire constituting the second winding block and the second wire constituting the third winding block are separated from each other.

Abstract: A system for testing a phase leg of an inverter includes a load coupled to an output terminal of the phase leg. A test circuit includes a capacitor coupled between an inverter power input and a switch module operative to couple the capacitor to the load. The circuit further includes a switch operative to select a polarity of a voltage across the capacitor. The circuit also includes a pair of switching elements operative to selectively couple the first terminal to the inverter power input and the inverter power return. The components can be operated by a controller configured to selectively couple the load to the inverter power and return terminals, selectively charge and couple the capacitor to the load, and interface with the inverter to control a path of current flow through active and passive elements of the phase leg.

Abstract: A power receiving device and a power feeding system which are capable of performing communication and power feeding at the same time are provided. Further, a power receiving device and a power feeding system which are capable of stably performing communication during power feeding are provided. One embodiment of the present invention relates to a power receiving device which includes an antenna for communication and power feeding that receives AC power, a rectifier circuit that rectifies the received AC power including the modulation signal into DC power, a smoothing circuit that smoothes the resulting DC power, a power storage device that stores the smoothed DC power, a communication control unit that analyzes the modulation signal included in the AC power, and a transformer that is positioned between the antenna and the rectifier circuit and changes a reference potential of the AC power, and a power feeding device.

Abstract: A power supply module includes first and second outer surfaces that are adjacent to and perpendicular or substantially perpendicular to each other. The power supply module includes a substrate that includes a first surface and a side surface, electronic components mounted at least on the first surface, a first resin material provided on the first surface, and terminal electrodes exposed at least at the first outer surface. The first resin member seals the electronic components mounted on the first surface. In the substrate, the first surface is perpendicular or substantially perpendicular to the first outer surface, which extends at least across the side surface of the substrate and the first resin member. The area of the first outer surface is smaller than the area of the second outer surface.

Abstract: The present disclosure relates to a sensor arrangement for use in process automation, having a sensor, comprising a first coupling body, having at least one sensor element for detecting a measurement value of the process automation, and a first interface for transmitting a signal dependent upon the measurement value, a connection element for transmitting the signal to a superordinate unit, comprising a second coupling body complementary to the first coupling body, having a second interface complementary to the first interface, wherein the first and second interfaces are designed for bi-directional communication between sensor and superordinate unit, where the sensor has at least one light source for transducing the signal dependent upon the measurement value into light of a color corresponding to the measurement value.

Abstract: The wireless power receiving module is disclosed. According to one embodiment of the present invention, the wireless power receiving module, to interact with a wireless power transmitting module including at least one wireless power transmitting antenna and a permanent magnet, includes an antenna unit including the wireless power receiving antenna formed of a hollow portion having a predetermined area at a central portion of a pattern portion and a shielding unit disposed on one surface of the antenna unit so as to shield a magnetic field. The shortest length between the inner sides of a coil pattern portion facing each other is the same as or larger than a diameter of the permanent magnet.

Abstract: A wireless power supply system includes a power transmitter and a power receiver. The power transmitter includes a power-transmitting coil to which AC power of a frequency is input from a power source. The power receiver includes a power-receiving coil magnetically coupled to the power-transmitting coil at a coupling coefficient, and a first power-receiving-side series element coupled in series to the power-receiving coil and having imaginary impedance jZS2i. In this wireless power supply system, the frequency and the imaginary impedance are determined so that impedance of a power-receiving side seen from the power source is independent of the coupling coefficient when the coupling coefficient changes.

Abstract: A standard inductance box, relating to the fields of measurement or calibration, and relating in particular to a standard gauge for transferring an inductance parameter. The standard inductance box uses unary, binary and quinary, and comprises a physical inductance box section and a simulated inductance box section, said sections being respectively arranged in a metal box. Electrodes of the physical inductance box section and the simulated inductance box section are led out. The inductance range of the standard inductance box is 1 ?H-500 H. The described means achieve an inductance range of 1 ?H-500 H, expanding the inductance range in the prior art, and the application of a simulated inductance box. Using unary, binary and quinary standards reduces the size and weight of the physical inductance box section, facilitating transportation and use in the field.

Abstract: A liquid ejecting apparatus includes: a liquid ejecting section that ejects liquid in response to a drive signal; a drive signal generation circuit that generates the drive signal by using a second frequency band including at least a part of a first frequency band; a non-contact power transmission circuit that transmits power in a non-contact manner by using the first frequency band; and a case body that surrounds the drive signal generation circuit and the non-contact power transmission circuit and includes a first surface and a second surface that faces the first surface, in which the drive signal generation circuit is arranged at a position closer to the first surface than to the second surface, and in which the non-contact power transmission circuit is arranged at a position closer to the second surface than to the first surface.

Abstract: A radiation imaging apparatus, which comprises a sensor array in which a plurality of pixels are arranged in a matrix form, cyclically perform a storing operation that stores charge in the pixels and a reading out operation that reads out the charge stored in the pixels, based on a synchronization signal comprised of a cyclical pulse train and a timing control signal synchronized to the synchronization signal. The radiation imaging apparatus changes a phase of the timing control signal in relation to the synchronization signal in accordance with a range of a partial region for trimming in a region of the sensor array in which read out is possible.

Abstract: An antenna-based modular power system includes a prime power supply configured to generate a first alternating current (AC) power signal having a first AC voltage level. At least one transformer is configured to convert the first AC signal into a second AC signal having a second AC voltage level less than the first AC voltage level. At least one Transmit or Receive Integrated Microwave Module (T/RIMM) dual power converter antenna array is in signal communication with the at least one transformer. The at least one T/RIMM dual power converter antenna array includes at least one load, and an AC/DC converter is embedded therein to convert the second AC signal into a DC power drive signal to energize the at least one load.

Abstract: A field device includes a current output circuit, a sensor circuit, and a terminal portion. The current output circuit and the sensor circuit are connected a two-wire loop wiring via the terminal portion in a state that the current output circuit and the sensor circuit are connected in series with each other. A rectifying element is connected to only a sensor circuit side of the terminal portion.

Abstract: Techniques for reducing particle contamination on a substrate are disclosed. In one particular exemplary embodiment, the technique may be realized with a platen having different regions, where the pressure levels in the regions may be substantially equal. For example, the platen may comprise a platen body comprising first and second recesses, the first recess defining a fluid region for holding fluid for maintaining a temperature of the substrate at a desired temperature, the second recess defining a first cavity for holding a ground circuit; a first via defined in the platen body, the first via having first and second openings, the first opening proximate to the fluid region and the second opening proximate to the first cavity, wherein pressure level of the fluid region may be maintained at a level that is substantially equal to pressure level of the first cavity.

Abstract: A method includes: receiving vehicle information from a wireless charging-capable vehicle via a wireless communication means; calculating an air gap between a primary coil of a wireless charging system that is operable to wirelessly charge the vehicle and a secondary coil of the vehicle based on the received vehicle information; and causing electric current to flow only through a portion of the primary coil having a size that is less than or equal to a size of the entire primary coil. The size of the portion of the primary coil through which the electric current flows is determined based on the calculated air gap between the primary coil and the secondary coil.

Abstract: Exemplary embodiments are directed to detecting and limiting power transfer to non-compliant devices. A method may include detecting one or more non-compliant devices positioned within a charging region of a wireless power transmitter. The method may further include limiting an amount of power delivered to at least one of the one or more non-compliant devices.

Abstract: An electric power transmission system may include: a power transmission antenna that constitutes a series resonator with an inductance component of L1 and a capacitance component of C1, and to which AC power is input; a power receiving antenna that constitutes a series resonator with an inductance component of L2 and a capacitance component of C2, and which receives electromagnetic energy from the power transmission antenna via electromagnetic fields; a rectifying unit that rectifies an output of the power receiving antenna to output DC power; and a load to which an output of the rectifying unit is input, wherein, when a coupling coefficient between the power transmission antenna and the power receiving antenna is k, if load resistance value R is used in a range that satisfies Rmin?R?Rmax, the following relationships are established: L 1 ? C 1 = L 2 ? C 2 ? ? and ( 2 ) L 1 C 1 > L 2 C 2 ? ? and ( 6 ) R m ? ? i ? ? n ? k ? L 2 C 2

Abstract: An electric power transmission system can include: a power transmission antenna that constitutes a series resonator with an inductance component of L1 and a capacitance component of C1, and to which AC power is input; a power receiving antenna that constitutes a series resonator with an inductance component of L2 and a capacitance component of C2, and which receives electromagnetic energy from the power transmission antenna via electromagnetic fields; a rectifying unit that rectifies an output of the power receiving antenna to output DC power; and a load to which an output of the rectifying unit is input, wherein, at times including when a coupling coefficient between the power transmission antenna and the power receiving antenna is k, if a load resistance value is R, the following relationships are established: L 1 ? C 1 = L 2 ? C 2 ; L 1 C 1 > L 2 C 2 ; and ? ? k ? L 2 C 2 ? R .

Abstract: A power feeding apparatus is provided. The power feeding apparatus includes a power feeding unit configured to supply electric power to a power receiving apparatus through a magnetic field; a measuring unit configured to measure an electric characteristic value and to generate a measurement value; a power receiving unit configured to provide a set value; and a foreign substance detection unit configured to detect a foreign substance in the magnetic field based on the set value and the measurement value. A power receiving apparatus, a power feeding system, and a method of controlling power feeding are also provided.

Abstract: The invention relates to an apparatus for charging a remote feedable circuit bioelectronic implanted in a patient or in a laboratory animal, said apparatus comprising a composable container configured to define a closed environment suitable to receive a patient or a laboratory animal, said container comprising a plurality of composable walls made of a nonmagnetic material and connected to each other so as to define said closed environment, said container comprising at least one first winding whose axis is arranged in a first direction (Z) and at least one second winding whose axis is arranged in a second direction (Y) perpendicular to said first direction (Z).

Abstract: An arrangement for use in a utility meter includes at least one circuit path, a three phase service switch, and a three phase monitoring unit. The at least one circuit path operably couples a source of electrical energy to a load. The service switch is operably coupled to the at least one circuit path and is configurable in an open state and a closed state. The monitoring unit is operably coupled to the at least one circuit path between the load and the service switch and is configured to detect a presence and an absence of line voltage on the load. The monitoring unit is further configured (i) to generate an open circuit signal responsive to the detection of the absence of line voltage on the load, and (ii) to generate a closed circuit signal responsive to the detection of the presence of line voltage on the load.

Abstract: Disclosed herein is a furniture having a wireless charging function, including: one or more transmission coil units disposed on the same plane of a flat plate of the furniture; and a central transmission controlling unit configured to select at least one transmission coil unit corresponding to a wireless power reception apparatus when the wireless power reception apparatus is placed on the flat plate, and to transmit a wireless power signal through the selected transmission coil unit, the central transmission controlling unit being installed separately from the plurality of transmission coil units.

Abstract: A battery system includes a plurality of electronic storage modules serially connected together. Each electronic storage module includes a battery block group including a plurality of battery cells, and a different magnetic core connected to each battery block group. An electronic device, an electric vehicle and electric power system including the battery system are also provided.

Abstract: In a method for detecting an electrically conductive foreign body at a device for inductively transmitting electrical energy from a stationary unit having an electrical power supply unit and a primary inductor to a mobile unit having a secondary inductor and an electric load, electrical power is initially fed from the electrical power supply unit into the primary inductor and the feed-in is interrupted. The curve over time of the resulting decay of an electrical operating variable of the primary inductor is measured and at least one parameter of the measured curve is compared with a corresponding parameter of a reference curve in the event of an interruption of the power feed-in into the primary inductor without the presence of an electrically conductive foreign body. The comparison is used to determine whether an electrically conductive foreign body is present in the region of the magnetic field produced by the primary inductor.

Abstract: There is provided a frequency controller apparatus for use in a wireless power transmitter apparatus configured to wirelessly transmit an inputted power from a power transmitting antenna that includes a first resonant circuit, toward a power receiving antenna that includes a second resonant circuit and is electromagnetically coupled to the power transmitting antenna at a predetermined transmission frequency. The frequency controller apparatus includes a controller for changing the transmission frequency during a power transfer, and the controller sets a decrease amount when decreasing the transmission frequency, so that the decrease amount is smaller than an increase amount when the transmission frequency is increased.

Abstract: An energy supply network for an aircraft or spacecraft, comprising at least one energy generating device for generating electrical energy, comprising at least two energy control devices, at least one of which is coupled directly to at least one of the energy generating devices and which are adapted each to provide a controlled supply voltage so as to supply electrical loads located in the aircraft with energy, and comprising a high-voltage direct current transmission device, which couples the at least two energy control devices to one another by means of high-voltage direct current transmission. Further, a method for supplying energy, and an aircraft or spacecraft.

Abstract: A coil component includes an air-core winding wire portion wound by a wire with a plurality of wound layers by alignment winding, a spiral shaped wound portion in which the wire wound in a spiral shape from an inner edge of an end surface toward an outer edge thereof along the end surface while in contact with the end surface on one side in the axis direction of the winding wire portion, a first lead portion extended and extracted outward from a winding first end point of the spiral shaped wound portion, and a second lead portion extended and extracted outward from a winding second end point at the outer circumference of the winding wire portion.

Abstract: An electric power receiving apparatus including: an electric power receiving coil disposed in a position where a receiving voltage is induced by a magnetic field from an electric power feeding apparatus; a measuring coil disposed in a position where a monitoring induced voltage as a voltage corresponding to the receiving voltage is induced by the magnetic field; and a foreign object detecting portion generating an amount of change in an impedance of the electric power receiving coil from the monitoring induced voltage and an induced current of the electric power receiving coil, thereby detecting a foreign object in the magnetic field based on the amount of change.

Abstract: There is disclosed a method and apparatus for generating an output signal comprising a replica of an input signal, comprising the steps of: generating a replica signal representing the low frequency content of the input signal; generating an error signal representing an error in the replica signal; combining the replica signal with the error signal to generate an output signal; and wherein the step of generating the error signal further includes the steps of: generating a delay signal being a delayed version of the input signal; and determining a difference between the output signal and the delay signal which difference is the error signal.

Abstract: An inductive power transfer system comprises a primary unit operable to generate an electromagnetic field and at least one secondary device, separable from the primary unit, and adapted to couple with the field when the secondary device is in proximity to the primary unit so that power can be received inductively by the secondary device from the primary unit without direct electrical conductive contacts therebetween. The system detects if there is a substantial difference between, on the one hand, a power drawn from the primary unit and, on the other hand, a power required by the secondary device or, if there is more than one secondary device, a combined power required by the secondary devices. Following such detection, the system restricts or stops the inductive power supply from the primary unit. Such a system can detect the presence of unwanted parasitic loads in the vicinity of the primary unit reliably.

Abstract: There is provided a system that includes a charger and a portable device. The portable device is coupled to the charger via a coupling capacitance. The charger provides a relatively constant current to the portable device, even for a relatively large variation in the coupling capacitance.