Touch sensor excitation using transformer

    公开(公告)号:US10585502B2

    公开(公告)日:2020-03-10

    申请号:US15680088

    申请日:2017-08-17

    申请人: Apple Inc.

    摘要: Input device power consumption can be reduced with a magnetic drive system. In some examples, the input device can include a transformer configured to generate a desired high output voltage from logic-level input pulses. In some examples, the distributed capacitance and associated resonance of the transformer can act as a low-pass filter, and can create a relatively clean output waveform from input logic signal waveforms. In some examples, the transformer can be an autotransformer. In some examples, to stabilize an amplitude of the output by sampling the output of the transformer and adjusting the input to the transformer based on the sampled output.

    Wireless Power System With Low Power Mode Switching

    公开(公告)号:US20190312459A1

    公开(公告)日:2019-10-10

    申请号:US16051350

    申请日:2018-07-31

    申请人: Apple Inc.

    IPC分类号: H02J50/10 H02J7/02 G06F3/0354

    摘要: A wireless power system has a wireless power transmitting device that uses an inverter to apply alternating-current signals to a coil. In response, the coil generates wireless power signals that are received by a coil in a wireless power receiving circuit of a wireless power receiving device. While wireless power is being transferred to the receiving device, the receiving device communicates with the wireless power transmitting device using in-band communications. The wireless power receiving device can issue a halt-wireless-power-transmission command using in-band communications to direct the wireless power transmitting device to stop transmitting wireless power. When power is not being transferred, the wireless power transmitting device transmits a series of short impulses that are monitored by the receiving device. The receiving device can direct the transmitting device to resume power transmission by adjusting an adjustable impedance circuit coupled to the wireless power receiving circuit.