Apple Inc.

Hunter H Wu

Brandon Pierquet

Jouya Jadidian

Paul W Firehammer

Hamza W Derbas

Anlang Lu

Robert J Kromer

A high-voltage DC floating system includes a source, a power rail, a power bus, a load, and a pre-charge circuit. The power bus includes a positive bus portion and a negative bus portion. The pre-charge circuit includes a first pre-charge circuit portion that is configured to equalize a voltage across the positive power supply switch between the source and a Y-capacitance of the load and a second pre-charge circuit portion that defines a switched path to ground that is configured to equalize a voltage associated with a Y-capacitance of the negative power rail.

Capacitance pre-charging

Wireless power transmitting equipment has a wireless power transmitter that includes a power converter and a radio-frequency inverter. The radio-frequency inverter may have an output coupled to a transmitting coil circuit formed from a capacitor coupled in series with a wireless power transmitting coil. Feedback information such as information on an output voltage from a rectifier in wireless power receiving equipment is wirelessly transmitted to the wireless power transmitting equipment. Signal phase and amplitude information such as the rectifier output voltage, current measurements in the wireless power receiver, and current and voltage phase and amplitude measurements made using a voltage sensor across the radio-frequency inverter output and a current sensor in series with the transmitting coil circuit may be used by the wireless power transmitting equipment to control the wireless power transmitter and thereby adjust wireless power transmission levels.

Wireless power control system

Wireless power transmitting equipment may transmit wireless power signals to wireless power receiving equipment. The wireless power transmitting equipment may have a wireless power transmitter coupled to a wireless power transmitting coil. The wireless power receiving equipment may have a wireless power receiving coil coupled to wireless power receiving circuitry such as a rectifier. Foreign object detection coil arrays may be formed from arrays of metal traces on printed circuit substrates that overlap the wireless power transfer coils. Control circuitry in the transmitting equipment and the receiving equipment may monitor signals from foreign object detection circuitry that is coupled to the coil arrays. The foreign object detection circuitry may produce in-phase and quadrature signals that are indicative of whether a foreign object is overlapping a foreign object detection coil array.

Growing community of inventors

San Jose, CA, United States of America

Hunter H Wu