A circuit split type wireless charging device
By separating the resonant circuit from the coil board and the main control circuit from the interface board, the problems of high line loss and increased housing size in wireless charging devices are solved, achieving faster charging speeds and lower costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHAOYANG KUZHIZAO TECH CO LTD
- Filing Date
- 2025-06-10
- Publication Date
- 2026-06-09
AI Technical Summary
In existing wireless charging devices, the long distance between the inverter circuit and the coil leads to high line losses, increased housing size, and increased costs.
It adopts a split structure, with the resonant circuit set on the coil board of the wireless charging module and the main control circuit set on the interface board. They are connected by a power cable, which reduces heat accumulation and line loss, and eliminates the need for an additional housing design.
Improve charging speed, reduce costs, avoid power reduction due to temperature rise, and achieve a compact structural design.
Smart Images
Figure CN224342951U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of charging device technology, and in particular to a split-type wireless charging device for charging electronic products such as mobile phones and smartwatches. Background Technology
[0002] Wireless charging is popular among many users due to its convenience. A wireless charger typically includes a wireless charging module and a power cord. The power cord has an interface through which a power adapter is plugged in to power the wireless charging module. Traditional wireless chargers integrate magnets, coils, and circuit boards into the charging module, leading to heat concentration, increasing the risk of burn-out, and also affecting charging speed. To address this, wireless chargers have been optimized with a split structure, primarily by separating a portion of the circuitry from the charging module to distribute heat effectively. For example, the wireless charging device disclosed in Chinese Utility Model Patent CN202010652429.4, by independently encapsulating the wireless charging coil, avoids the problem of the charging coil overheating during high-power charging, thus preventing the device being charged from overheating. However, this solution still has some problems. First, placing the inverter circuit (or resonant circuit, oscillation circuit) in the first housing and then connecting it to the wireless charging coil via a cable results in a relatively large distance between the inverter circuit and the coil, leading to greater line losses and thus significant power waste. Second, placing all the various circuit components in the first housing significantly increases the size of the first housing, requiring an additional, larger first housing and thus increasing costs. Utility Model Content
[0003] This invention addresses the shortcomings of existing technologies by providing a wireless charging device with a simpler and more compact structure, lower cost, no additional line losses, improved charging speed, and no need for a separate casing.
[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a wireless charging device with a separate circuit, comprising a wireless charging module and a power cord. The wireless charging module includes a coil, the power cord has an interface, an interface board is provided in the interface, a coil board is provided in the wireless charging module, and a resonant circuit for driving the coil is provided on the coil board; an MCU main control circuit and a temperature detection circuit for controlling the operation of the coil and the resonant circuit are provided on the interface board, and the interface board and the coil board are connected to each other through the power cord. The interface board and the coil board together constitute the control circuit board of the wireless charging module.
[0005] Furthermore, the temperature detection circuit is an interface board and coil board temperature detection circuit, which uses an NTC as the detection element and is connected to the main control MCU of the MCU main control circuit. The main control MCU uses the MT5805 chip.
[0006] Furthermore, a coil board temperature detection circuit is also provided on the coil board. The coil board temperature detection circuit is connected to the coil and uses an NTC as the detection element.
[0007] Furthermore, the MCU main control circuit is connected to a full-bridge filter circuit, a bootstrap circuit, a current detection circuit, and two half-bridge electromagnetic compatibility circuits.
[0008] Furthermore, a fast charging protocol circuit and a switch / protection circuit are also provided on the interface board, which are connected to the main control MCU respectively.
[0009] Furthermore, a Q-value detection circuit is also provided on the coil board, and the Q-value detection circuit is connected to the resonant circuit.
[0010] Furthermore, a modulation and demodulation circuit is also provided on the coil board, which is connected to the Q-value detection circuit and the resonant circuit.
[0011] Preferably, the interface uses a USB-A, TP-YE-C, or MICRO-USB interface.
[0012] This invention adopts a split structure, placing the main control circuit on the interface board at the interface end and the resonant circuit on the coil board of the wireless charging module. This close proximity of the resonant circuit to the coil isolates the main heat source from the coil and solves the problem of significant line loss caused by a long distance between the resonant circuit and the coil. This prevents the wireless charger from overheating during operation and requiring it to reduce power, thus improving charging speed and shortening charging time. Furthermore, the small size of the main control circuit allows it to be directly mounted on the interface board of the power cord interface without the need for an additional casing, thereby reducing costs. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the physical structure of this utility model;
[0014] Figure 2 This is a schematic block diagram of the circuit of this utility model;
[0015] Figure 3 This is the schematic diagram of the main control circuit of this utility model;
[0016] Figure 4 This invention provides the circuit schematics for the fast charging protocol and the switch / protection circuit when using the USB-A port as the input interface.
[0017] Figure 5 This is a schematic diagram of the temperature detection circuit for the interface board and coil board of this utility model.
[0018] Figure 6 This is a circuit diagram of the coil board temperature detection circuit of this utility model;
[0019] Figure 7 This is a schematic diagram of the resonant circuit of this utility model;
[0020] Figure 8 This is a schematic diagram of the modulation and demodulation circuit of this utility model;
[0021] Figure 9 This invention provides the circuit schematics for the fast charging protocol and the switch / protection circuit when using a Type-C port as the input interface.
[0022] Figure 1 and Figure 2 In the diagram, 1 is the coil, 2 is the coil board, 3 is the interface, 4 is the interface board, and 5 is the power cord. Detailed Implementation
[0023] In this embodiment, refer to Figures 1-9 The described split-type wireless charging device includes a wireless charging module and a power cord 5. The wireless charging module includes a coil 1, a magnet, etc. The power cord 5 has an interface 3 for connecting a power adapter. An interface board 4 is provided in the interface 3. A coil board 2 is provided in the wireless charging module, and a resonant circuit for driving the coil 1 is provided on the coil board 2. An MCU main control circuit and a temperature detection circuit for controlling the operation of the coil 1 and the resonant circuit are provided on the interface board 4. The interface board 4 and the coil board 2 are connected to each other through the power cord 5. The interface board 4 and the coil board 2 together constitute the control circuit board of the wireless charging module. This design keeps the main circuit away from the coil 1, avoiding the superposition of heat from the main circuit and the coil 1; however, the resonant circuit is very close to the coil 1, avoiding large line losses in the resonant circuit due to long-distance current transmission.
[0024] The temperature detection circuit consists of an interface board and a coil board temperature detection circuit. It uses an NTC sensor and is connected to the main MCU of the MCU control circuit. The main MCU uses the MT5805 chip, but a similar chip can also be used. A coil board temperature detection circuit is also located on coil board 2, connected to the coil, and uses an NTC sensor. This circuit monitors the temperature of coil 1 and the switching transistor, triggering over-temperature protection. The main MCU is responsible for the overall control logic, such as starting / stopping charging and power regulation.
[0025] The MCU main control circuit is connected to a full-bridge filter circuit, a bootstrap circuit, a current detection circuit, and two half-bridge electromagnetic compatibility circuits. The function of the full-bridge filter circuit, bootstrap circuit, current detection circuit, and two half-bridge electromagnetic compatibility circuits is to generate a high-frequency square wave signal by alternately turning on the switching transistors (such as MOSFETs or IGBTs).
[0026] The interface board also includes a fast charging protocol circuit and a switch / protection circuit, both of which are connected to the main control MCU. The fast charging protocol circuit enables fast charging, while the switch / protection circuit prevents unstable adapter output from damaging the wireless charging circuit.
[0027] A Q-value detection circuit and a modulation / demodulation circuit are also set on the coil board. The Q-value detection circuit is connected to the resonant circuit, and the modulation / demodulation circuit is connected to both the Q-value detection circuit and the resonant circuit. The resonant circuit consists of an LC resonant circuit composed of a capacitor and a coil, tuned to a specific frequency (e.g., 100-300 kHz) to charge devices such as mobile phones. The Q-value detection circuit monitors the quality factor of the resonant circuit, enabling the system to dynamically optimize its operating state, promptly identify foreign objects, and prevent energy waste. The receiver of the modulation / demodulation circuit transmits data, such as device ID and power requirements, to the transmitter through load modulation. Alternatively, the modulation / demodulation circuit can also be set on the interface board.
[0028] The interface uses USB-A, TP-YE-C, or MICRO-USB interfaces, and the specific interface type can be set according to requirements.
[0029] The present invention has been described in detail above. The above description is only a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of this application should still fall within the scope of the present invention.
Claims
1. A wireless charging device with a separate circuit, comprising a wireless charging module and a power cord, wherein the wireless charging module includes a coil, the power cord has an interface, and an interface board is disposed in the interface, characterized in that: The wireless charging module includes a coil board, on which a resonant circuit for driving the coil is located. The MCU main control circuit and temperature detection circuit for controlling the coil and resonant circuit are located on the interface board. The interface board and the coil board are connected to each other via a power line. Together, the interface board and the coil board constitute the control circuit board of the wireless charging module.
2. The circuit-split wireless charging device according to claim 1, characterized in that: The temperature detection circuit is an interface board and coil board temperature detection circuit. It uses an NTC as the detection element and is connected to the main control MCU of the MCU main control circuit. The main control MCU uses the MT5805 chip.
3. The circuit-split wireless charging device according to claim 1, characterized in that: A coil board temperature detection circuit is also provided on the coil board. The coil board temperature detection circuit is connected to the coil and uses NTC as the detection element.
4. The circuit-split wireless charging device according to claim 2, characterized in that: The MCU main control circuit is connected to a full-bridge filter circuit, a bootstrap circuit, a current detection circuit, and two half-bridge electromagnetic compatibility circuits.
5. The circuit-split wireless charging device according to claim 1, characterized in that: The interface board also includes a fast charging protocol circuit and a switch / protection circuit, which are connected to the main control MCU.
6. The circuit-split wireless charging device according to claim 1, characterized in that: A Q-value detection circuit is also provided on the coil board, and the Q-value detection circuit is connected to the resonant circuit.
7. The circuit-split wireless charging device according to claim 6, characterized in that: A modulation and demodulation circuit is also provided on the coil board, which is connected to the Q-value detection circuit and the resonant circuit.
8. The circuit-split wireless charging device according to claim 5, characterized in that: The interface uses a USB-A, TP-YE-C, or MICRO-USB interface.