Wireless charging circuit and device
This application provides a wireless charging circuit and a device. The wireless charging circuit includes a power supply module, an inverter module, and a first coil component; the first coil component includes at least one coil; the power supply module is connected to the inverter module, and the inverter module is connected to the first coil component; the power supply module is configured to: output a direct current signal to the inverter module; and the inverter module is configured to: convert the direct current signal into an alternating current signal at a target resonant frequency, and output the alternating current signal to the first coil component, where the target resonant frequency is at an MHz level. In this application, a stylus can obtain electric energy from a power supply device without being clung to the power supply device.
1 . A wireless charging circuit, applied to a power supply device and comprising: an inverter module, a power supply module, a first processing module, a first communication module and a first coil component, wherein the first coil component comprises: a coil gating submodule, a switching submodule and at least two coils;
the inverter module is connected to the first coil component;
the inverter module is configured to: obtain a direct current signal, convert the direct current signal into a first alternating current signal at a target resonant frequency, and output the first alternating current signal to the first coil component, wherein the target resonant frequency is at an MHz level;
the first coil component is configured to emit a wireless charging signal based on the first alternating current signal;
the first communication module configured to receive a required charging power from a stylus, and send the required charging power to the first processing module;
the power supply module is further configured to send power supply information to the first processing module;
the first processing module configured to obtain a writing position of the stylus on a screen, and determine a first target power based on the power supply information, the writing position of the stylus, and the required charging power, wherein a distance between the stylus and the first coil component is determined based on the writing position, and the first target power is positively correlated with the distance such that a larger distance indicates a higher first target power, and sending the first target power to the inverter module;
the inverter module is also used for: adjusting an output power of the inverter module to the first target power;
the stylus include a second processing module, a second communication module, and an electric quantity detection module;
the electric quantity detection module configured to detect electric quantity of batteries in a battery pack and send electric quantity information of the battery pack to the second processing module; and
the second processing module configured to interact with the power supply device in terms of a charging protocol by using the second communication module to charge a second battery pack in the stylus.
2 . The circuit according to claim 1 , wherein the coils are distributed at different positions of the power supply device; and
that the inverter module is connected to the first coil component comprises:
the inverter module is connected to each coil.
3 . The circuit according to claim 2 , wherein that the coils are distributed at different positions of the power supply device comprises: the coils are evenly distributed at different positions of the power supply device based on a screen of the power supply device.
4 . The circuit according to claim 2 , wherein the circuit further comprises a first processing module; and the switching submodule is connected to the first processing module and the coil gating submodule respectively;
that the inverter module is connected to each coil comprises: the inverter module is connected to each coil by using the coil gating submodule;
the first processing module is configured to: detect a writing position of a stylus on the screen, select a target coil from the coils in the first coil component based on the writing position, and send information of the selected target coil to the switching submodule; and
the switching submodule is configured to: control the coil gating submodule to gate a path between the target coil and the inverter module based on the information of the target coil.
5 . The circuit according to claim 4 , wherein the coil gating submodule comprises a plurality of switches; and each coil in the first coil component corresponds to one switch;
that the inverter module is connected to each coil by using the coil gating submodule comprises: the inverter module is connected to each coil by using a switch corresponding to the coil; and
that the switching submodule is configured to control the coil gating submodule to gate a path between the target coil and the inverter module comprises: the switching submodule is configured to: control a switch corresponding to the target coil to turn on, and control a switch corresponding to a coil other than the target coil to turn off.
6 . The circuit according to claim 4 , wherein the circuit further comprises:
a first communication module, configured to receive a charging request from the stylus, and send the charging request to the first processing module; and further configured to receive a charging stop request from the stylus, and send the charging stop request to the first processing module; wherein
the first processing module is further configured to: control the inverter module to start operating when it is determined, based on the charging request, to charge the stylus; and control the inverter module to stop operating when it is determined, based on the charging stop request, to stop charging the stylus.
7 . The circuit according to claim 1 , wherein the coils are planar coils.
8 . A wireless charging circuit, applied to a stylus and comprising: a second coil component, a rectifier module, a second processing module, a second communication module, and an electric quantity detection module, wherein
the second coil component is connected to the rectifier module;
the second coil component is configured to: receive a wireless charging signal, at a target resonant frequency, emitted by a power supply device, convert the wireless charging signal into a second alternating current signal, and transmit the second alternating current signal to the rectifier module; wherein the target resonant frequency is at an MHz level; and
the rectifier module is configured to: rectify the second alternating current signal into a direct current signal, and the direct current signal is used to charge a battery pack of the stylus and/or supply power to a power circuit of the stylus;
the electric quantity detection module is configured to detect electric quantity information of the battery pack in the stylus, and send a detection result to the second processing module; and
the second processing module is configured to calculate a required charging power based on the detection result, and send the required charging power to the power supply device by using the second communication module to cause the power supply device to adjust an output power of the wireless charging signal based on a writing position of the stylus.
9 . The circuit according to claim 8 , wherein the second processing module is configured to send a charging request to the power supply device by using the second communication module, wherein the charging request is used to request the power supply device to send a wireless charging signal; and is further configured to send a charging stop request to the power supply device by using the second communication module, wherein the charging stop request is used to request the power supply device to stop sending the wireless charging signal.
10 . The circuit according to claim 9 , further comprising:
wherein the electric quantity detection module is configured to: detect electric quantity information of the battery pack in the stylus, and send a detection result to the second processing module; wherein
that the second processing module is configured to send a charging request to the power supply device by using the second communication module comprises: the second processing module is configured to send a charging request to the power supply device by using the second communication module when it is determined, based on the detection result, to perform wireless charging; and
that the second processing module is configured to send a charging stop request to the power supply device by using the second communication module comprises: the second processing module is configured to send a charging stop request to the power supply device by using the second communication module when it is determined, based on the detection result, to stop wireless charging.
11 . The circuit according to claim 10 , wherein the second processing module is further configured to: control the rectifier module to start rectifying the second alternating current signal output by the second coil component when it is determined, based on the detection result, to perform wireless charging; and control the rectifier module to stop the rectifying when it is determined, based on the detection result, to stop wireless charging.
12 . A stylus, comprising the wireless charging circuit according to claim 8 .