Koninklijke Philips Corporation N.v.

Eddy Gerrit Veltman

Wilhelmus Gerardus Maria Ettes

Andries Van Wageningen

Antonius Adriaan Maria Staring

Klaas Jacob Lulofs

Johannes Gerardus Fredericus Kablau

Henricus Antonius Gerardus Van Vugt

Richard Henricus Maria Theelen

Neil Francis Joye

Hedzer Durksz

Liesbet Hillechina Wind

Lennaert Quirijn Bronts

Matthijs Jaap Wolter Ten Hove

A wireless power transmitter () comprises a driver () generating a drive signal for a transmitter coil () thereby generating a power transfer signal during power transfer intervals of a repeating time frame comprising at least one power transfer interval and one foreign object detection interval. A test generator () generates a test drive signal for a test coil () thereby generating an electromagnetic test signal during foreign objectdetection intervals. A foreign object detector () performs a foreign object detection test in response to a measured parameter for the test drive signal during the foreign object detection intervals. An adapter () generates a varying test drive signal for the test coil () during an adaptation interval, and determines a test drive signal parameter value in response to the varying test drive signal. The test generator () sets a signal property of the test drivesignal during at least one foreign object detection interval in response to the test drive signal parameter value.

Foreign object detection in a wireless power transfer system

A power transfer device is a power transmitter () or a power receiver () conducting power transfer using an electromagnetic power transfer signal employing a repeating time frame comprising a power transfer time interval and an object detection time interval. A power transfer circuit () comprises a power transfer coil () receiving or generating the power transfer signal during the power transfer time intervals. A communicator () communicates with the other device via an electromagnetic communication signal. A communication resonance circuit () comprises a communication antenna () for transmitting or receiving the electromagnetic communication signal. During the communication, the communication resonance circuit () provides a resonance at a first resonance frequency to the communicator (). A controller () adapts the communication resonance circuit to not provide the resonance at the first resonance frequency to the communicator during object detection time intervals. The approach may provide improved detection of resonance objects, such as smart cards (e.g. NFC cards).

Device and method for wireless power transfer

A power transmitter () for a wireless power transfer system comprises a transmitter coil () and a driver () generates a drive signal for the transmitter coil () employing a repeating time frame with a power transfer time interval and a foreign object detection time interval. A test generator () generates a test drive signal for a test coil () during the foreign object detection time interval. A foreign object detector () performs a foreign object detection test based on a measured parameter for the test drive signal. Prior to entering a power transfer phase, an adapter () controls the power transmitter () to operate in a foreign object detection initialization mode in which a preferred value of a signal parameter for the test drive signal is determined in response to at least a first message received from the power receiver (). During the foreign object detection time interval the signal parameter of is set to the preferred value.

This application relates to methods and apparatus for powering microcontrollers (), in particular for powering microcontrollers of a personal care product, such as a shaver product (). The microcontroller is arranged such that a first output port (-) of a plurality of output ports of the microcontroller receives, in use, an AC waveform. Each output port has an associated high-side switch () electrically connected between the output port and a high-side DC voltage rail and an associated low-side switch () electrically connected between the output port and a low-side DC voltage rail. A processing module () of the microcontroller is configured to monitor a phase of the AC waveform and to control switching of the associated high-side and low-side switches of the first output port based on the phase of the AC waveform so as to provide a rectified voltage between the high-side DC voltage rail and the low-side voltage rail for powering the processing module. The processing module () also controls switching of the associated switches of at least a further output port to output a control signal for controlling at least one aspect of operation of a host device. The processing module is further configured to maintain the associated high-side switch of the first output port in a turned-off state when a monitored voltage of the AC waveform at the first output port is between zero and a monitored voltage at the high-side DC voltage rail, and to maintain the associated high-side switch of the first output port in a turned-on state when the monitored voltage of the AC waveform at the first output port is greater than the monitored voltage at the high-side DC voltage rail.

Powering microcontrollers

A power transmitter () for a wireless power transfer system includes a parallel resonance circuit () comprising at a transmitter coil () for generating the power transfer signal. A power source () has a current sink terminal and a power source terminal providing current to the parallel resonance circuit () with a limited rate of change of the current drawn. A first switch element () is coupled between a first end of the parallel resonance circuit () and the current sink terminal. A second switch element () is coupled between the other end and the current sink terminal. A driver () generates a cyclic drive signal such that each cycle comprises a two time intervals in which one switch element () is closed and the other () is open; and a third time interval in which both the first switch element () and the second switch element () are closed, the third time interval being between the other two intervals.

Power transmitter and method for wirelessly transferring power

A wireless power transmitter ()) comprises a resonance circuit () comprises a transmitter inductor () for generating a power transfer signal for wirelessly transferring power to the power receiver (). A driver () generates a drive signal for the resonance circuit () and a resonance modification circuit () aligns the resonance frequency of the resonance circuit () with the drive frequency of the drive signal by slowing a state change for resonance circuit () for a fractional time interval of cycles of the drive signal. A load estimator () generates a load estimate reflecting an equivalent load resistor for the transmitter inductor () reflecting the loading of the power transfer signal. A drive frequency adapter () then adapts the drive frequency in response to the load estimate. The invention may in particular improve load modulation communication quality.

Wireless inductive power transfer

A wireless power transfer system includes a power receiver and a power transmitter providing power using an inductive power signal. The power transmitter includes a resonance circuit having capacitive and inductive impedances, and a driver configured to generate a drive signal for the resonance circuit. A frequency modification circuit is configured to control the resonance frequency of the resonance circuit by slowing a state change for the capacitive and/or inductive impedance for a fractional time interval of at least some cycles of the drive signal, The frequency modification circuit is configured to align at least one of a start time and an end time for the fractional time interval to transitions of a timing signal. In the power transmitter, the driver is configured to generate the timing signal to have transitions synchronized to the drive signal. The slowing may be by impeding current flow between the capacitive and inductive impedances.

A wireless power transfer system includes a power receiver and a power transmitter providing power to this using an inductive power signal. The power transmitter comprises a variable resonance circuit () having a variable resonance frequency and generating the inductive power signal. A driver () generates the drive signal and a load modulation receiver () demodulates load modulation of the inductive power signal. An adaptor () adapts the operating frequency and the resonance frequency to converge, and specifically is arranged to control the operating frequency and the resonance frequency to be substantially the same. The adaptation of the operating frequency and the resonance frequency is further in response to a demodulation quality measure. The invention may allow improved communication, and in particular may reduce intermodulation distortion.

A personal care device comprising a main housing, a hair-cutting module displaceable with respect to the main housing against spring force in a direction parallel to a main axis, and a sensor comprising a first sensor unit connected to the main housing and a second sensor unit connected to the hair-cutting module. The hair cutting module is also tiltable in directions relative to the main housing. By measuring average displacement of the hair cutting module at multiple locations, the sensor is sensitive only to displacement parallel to the main axis. The sensor measures such displacement and determines the force needed to effect such displacement. If the force is larger than a predetermined value, a warning signal will be produced.

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Steenbergen, Netherlands

Eddy Gerrit Veltman