Abstract: This disclosure provides systems, methods, and apparatus for the limiting of voltage in wireless power receivers. In one aspect, an apparatus includes a power transfer component configured to receive power wirelessly from a transmitter. The apparatus further includes a circuit coupled to the power transfer component and configured to reduce a received voltage when activated. The apparatus further includes a controller configured to activate the circuit when the received voltage reaches a first threshold value and configured to deactivate the circuit when the received voltage reaches a second threshold value. The apparatus further includes an antenna configured to generate a signal to the transmitter that signals to the transmitter that the received voltage reached the first threshold value.

Abstract: This disclosure provides systems, methods, and apparatus for the limiting of voltage in wireless power receivers. In one aspect, an apparatus includes a power transfer component configured to receive power wirelessly from a transmitter. The apparatus further includes a circuit coupled to the power transfer component and configured to reduce a received voltage when activated. The apparatus further includes a controller configured to activate the circuit when the received voltage reaches a first threshold value and configured to deactivate the circuit when the received voltage reaches a second threshold value. The apparatus further includes an antenna configured to generate a signal to the transmitter that signals to the transmitter that the received voltage reached the first threshold value.

Abstract: Exemplary embodiments are directed to wireless power transfer. A wireless power transmitter includes a transmit antenna and a controller. The transmit antenna inductively transfers power to a plurality of receiver devices. The controller is operably coupled to the transmit antenna and causes a first one of the plurality of receiver devices to be enabled to receive the power from the transmit antenna and causes at least a portion of the remaining receiver devices to be disabled from receiving the power while the first receiver device is enabled.

Abstract: Aspects of a protection circuit and method are disclosed. A transmit circuit generates a power transmit signal for powering the transmit antenna to generate a wireless field sufficient for wirelessly charging a device. A detection circuit senses a strength of an electromagnetic field received by the transmit antenna and further configured to generate an sense signal indicating the strength of the electromagnetic field received by the transmit antenna. A power control circuit controls a switch based at least partly on the sense signal. The power control circuit can attenuate an electrical coupling between the transmit antenna and the transmit circuit such that the received electromagnetic field is inhibited from damaging the transmit antenna or the transmit circuit.

Abstract: Systems, methods, and apparatus are provided for tuning in wireless power transfer circuits. One aspect of the disclosure provides an apparatus for tuning. The apparatus includes a field effect transistor having a gate, source, and drain, where the field effect transistor is configured to electrically engage a tuning element to an AC power path. In some embodiments, one of the source or drain contacts is at an alternating current voltage.

Abstract: Systems, methods and apparatus are disclosed for amplifiers for wireless power transfer. In one aspect a method is provided for controlling operation of an amplifier, such as a class E amplifier. The method may include monitoring an output of the amplifier. The method may further include adjusting a timing of an enabling switch of the amplifier based on the output of the amplifier.

Abstract: An apparatus and method for communication with a wireless power transmitter are disclosed. According to one aspect, a device may include an antenna for wirelessly transmitting a power signal at a power carrier and data signal at a data signal carrier. A receiver may be configured to receive the power signal and the data signal and determine a reference signal based on the received signal.

Abstract: An apparatus, a method, and a computer program product are provided. The apparatus determines an input voltage and an input current of a power system driving a low power factor load, the input voltage varying based on a power cycle, determines at least a first portion of the power cycle at which the input current exceeds a threshold, and couples at least one substantially resistive load to the low power factor load during at least a second portion of the power cycle different from the at least a first portion of the power cycle.

Abstract: Exemplary embodiments are directed to wireless power transfer. A wireless power transmitter includes a transmit antenna and a controller. The transmit antenna inductively transfers power to a plurality of receiver devices. The controller is operably coupled to the transmit antenna and causes a first one of the plurality of receiver devices to be enabled to receive the power from the transmit antenna and causes at least a portion of the remaining receiver devices to be disabled from receiving the power while the first receiver device is enabled.

Abstract: Systems, methods and apparatus are disclosed for amplifiers for wireless power transfer. In one aspect a method is provided for controlling operation of an amplifier, such as a class E amplifier. The method may include monitoring an output of the amplifier. The method may further include adjusting a timing of an enabling switch of the amplifier based on the output of the amplifier.

Abstract: Exemplary embodiments are directed to wireless power transfer. A transmit antenna generates an electromagnetic field having a region for wirelessly transferring power from the transmit antenna to a plurality of receiver devices. A controller is operably coupled to the transmit antenna. The controller determines a power allocation for a particular one of the plurality of receiver devices disposed within the region, and adjusts the power allocation based at least in part on a power requirement received from the particular one of the plurality of receiver devices.

Abstract: Systems, methods, and apparatus are provided for tuning in wireless power transfer circuits. One aspect of the disclosure provides an apparatus for tuning. The apparatus includes a field effect transistor having a gate, source, and drain, where the field effect transistor is configured to electrically engage a tuning element to an AC power path. In some embodiments, one of the source or drain contacts is at an alternating current voltage.

Abstract: Systems, methods and apparatus are disclosed for amplifiers for wireless power transfer. In one aspect a method is provided for controlling operation of an amplifier, such as a class E amplifier. The method may include monitoring an output of the amplifier. The method may further include adjusting a timing of an enabling switch of the amplifier based on the output of the amplifier.

Abstract: An apparatus, a method, and a computer program product are provided. The apparatus determines an input voltage and an input current of a power system driving a low power factor load, the input voltage varying based on a power cycle, determines at least a first portion of the power cycle at which the input current exceeds a threshold, and couples at least one substantially resistive load to the low power factor load during at least a second portion of the power cycle different from the at least a first portion of the power cycle.

Abstract: Aspects of a protection circuit and method are disclosed. A transmit circuit generates a power transmit signal for powering the transmit antenna to generate a wireless field sufficient for wirelessly charging a device. A detection circuit senses a strength of an electromagnetic field received by the transmit antenna and further configured to generate an sense signal indicating the strength of the electromagnetic field received by the transmit antenna. A power control circuit controls a switch based at least partly on the sense signal. The power control circuit can attenuate an electrical coupling between the transmit antenna and the transmit circuit such that the received electromagnetic field is inhibited from damaging the transmit antenna or the transmit circuit.

Abstract: Exemplary embodiments are directed to wireless power transfer. A transmit antenna generates an electromagnetic field having a region for wirelessly transferring power from the transmit antenna to a plurality of receiver devices. A controller is operably coupled to the transmit antenna. The controller determines a power allocation for a particular one of the plurality of receiver devices disposed within the region, and adjusts the power allocation based at least in part on a power requirement received from the particular one of the plurality of receiver devices.

Abstract: An apparatus and method for communication with a wireless power transmitter are disclosed. According to one aspect, a device may include an antenna for wirelessly transmitting a power signal at a power carrier and data signal at a data signal carrier. A receiver may be configured to receive the power signal and the data signal and determine a reference signal based on the received signal.

Abstract: Systems, methods and apparatus are disclosed for amplifiers for wireless power transfer. In one aspect a method is provided for controlling operation of an amplifier, such as a class E amplifier. The method may include monitoring an output of the amplifier. The method may further include adjusting a timing of an enabling switch of the amplifier based on the output of the amplifier.