Apple Inc.

Zachary Strachan Harris

Bharat K Patel

Liang Chen

Antoin J Russell

Arunim Kumar

Wynand L Malan

Andrew Gray

Stephen Christopher Terry

Saining Ren

Ron Rafer Floresca

Jerald Polestico Guillermo

Ge Wang

A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may be a wireless charging mat or other device with a charging surface. The wireless power receiving device may be a portable electronic device receiving transmitted wireless power signals from the wireless power transmitting device while resting on the charging surface. During digital ping operations, low-power wireless power signals may be transmitted from the wireless power transmitting device. Information gathered during the digital ping such as wireless power transmission efficiency information, coupling coefficient information, Q-factor information, and coil inductance information may be used in determining whether a foreign object is present. Control circuitry in the transmitting device can cause the receiving device to present an alert for a user indicating that wireless power transfer operations are commencing in response to determining that no foreign object is present.

Wireless power system with foreign object detection

A wireless power transmitting device transmits wireless power signals to a wireless power receiving device using an output circuit that includes a wireless power transmitting coil. Measurement circuitry is coupled to the output circuit to help determine whether the wireless power receiving device is present and ready to accept transmission of wireless power. Oscillator circuitry for supplying signals to the output circuitry while making measurements with the measurement circuitry is coupled to the output circuit using an impedance injection network. The impedance injection network includes an inductor and a resistor coupled in series. Control circuitry opens a transistor in the output circuit when making measurements with the measurement circuitry and closes the transistor when transmitting the wireless power signals.

Wireless charging system having measurement circuitry with foreign object detection capabilities

A wireless power system has a wireless power transmitting device and a wireless power receiving device. During digital ping operations while the transmitting device and receiving device negotiate to establish a power level to use during normal operation, low-power wireless power signals may be transmitted to the receiving device from the wireless power transmitting device. Information gathered during the digital ping may be evaluated using a wireless-power-transmission-efficiency-to-digital-ping-rectifier-output-voltage relationship and using a normal-operation-wireless-power-transmission-efficiency-to-digital-ping-wireless-power-transmission-efficiency relationship to predict a wireless power transmission efficiency that would be experienced if the system were to enter normal operation. Based on this efficiency prediction, the system can issue alerts and can decide whether or not to enter normal operation.

Wireless power system with efficiency prediction

A wireless power transmitting device transmits wireless power signals to a wireless power receiving device using output circuitry that includes an array of wireless power transmitting coils that form a wireless charging surface. During wireless power transmission operations, wireless power signals are transmitted from the array of coils to a wireless power receiving device on the charging surface. Inductance measurement circuitry such as impulse response measurement circuitry and other measurement circuitry is coupled to the output circuitry. Control circuitry in the wireless power transmitting device analyzes signals from the measurement circuitry to produce two-dimensional signal profiles across the wireless charging surface and to compare patterns in these signal profiles to predetermined signal patterns associated with the presence of known power receiving equipment on the wireless charging surface. Based on the analysis, charging parameters may be adjusted or other actions taken.

Wireless charging system with object recognition

Growing community of inventors

Auckland, New Zealand

Zachary Strachan Harris