Wireless charging receiving circuit of wearable device

Abstract

The utility model relates to a kind of wireless charging receiving circuit of wearable equipment, including receiving circuit, voltage adjustment circuit, charging circuit and closing control circuit;When using, after being fully charged, closing control circuit will control voltage adjustment circuit, charging circuit to close, so that when using battery is fully charged, it needs to be separated from wireless charging seat first, then it is placed on wireless charging seat again to restore charging function, and the power equipment is fully charged and placed on wireless charging seat for a long time, and battery will not be repeatedly charged. The utility model has the characteristics of simple structure, reasonable design, automatic power-off after battery is fully charged, battery protection, energy saving and environmental protection, etc.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a wireless charging receiver circuit for wearable devices. Background Technology

[0002] Wearable medical devices refer to portable medical / health electronic devices that can be worn directly on the user's body for sensing, recording, analyzing, regulating, intervening in, and even treating diseases or maintaining a healthy state. With the development of wireless charging technology, some wearable medical devices now also use wireless charging technology for convenient charging.

[0003] Wireless charging technology includes a wireless charging transmitting circuit located in the charging dock and a wireless charging receiving circuit located in the device. Currently, in wearable medical devices, when the wireless charging receiving circuit is used, after the battery is fully charged and charging stops, if the device remains on the charging dock, the battery level will slightly decrease (e.g., to 98% or 99%), briefly initiating a small-current charging to fully charge it before stopping. While this design keeps the battery fully charged, the fact that the battery will resume charging after being fully charged, without being separated from the charging dock, will affect battery life over time and increase user costs. Furthermore, this continuous operation of the wireless charging receiving circuit after the battery is fully charged is not energy-efficient or environmentally friendly. Utility Model Content

[0004] The purpose of this utility model is to provide a wireless charging receiving circuit for wearable devices. This wireless charging receiving circuit for wearable devices has the advantages of simple structure, reasonable design, automatic power-off after the battery is fully charged, battery protection, and energy saving and environmental protection.

[0005] The technical solution of this utility model is implemented as follows: a wireless charging receiving circuit for a wearable device, specifically comprising a receiving circuit, a voltage adjustment circuit, a charging circuit, and a shutdown control circuit; wherein:

[0006] The receiving circuit includes a receiving coil L1, capacitors C1 and C2, and a Schottky barrier rectifier D1; one end of each of the receiving coil L1, capacitors C1 and C2 is grounded, the other end of each of the receiving coil L1 and capacitors C1 is electrically connected to the positive terminal of the Schottky barrier rectifier D1, and the other end of capacitor C2 is electrically connected to the negative terminal of the Schottky barrier rectifier D1.

[0007] The voltage adjustment circuit includes chip U1, resistors R1 and R2, capacitor C3, Schottky barrier rectifier D2, and inductor L2. Chip U1 is a TX4137. Pin 1 of chip U1 is floating; pin 2 of chip U1 is grounded; pin 3 of chip U1 is electrically connected to one end of each of resistors R1 and R2, and the other end of resistor R1 and one end of capacitor C3 are both electrically connected to one end of inductor L2. The other ends of resistor R2 and capacitor C3 are both grounded; pin 5 of chip U1 is electrically connected to the negative terminal of Schottky barrier rectifier D1; pin 6 of chip U1 is electrically connected to the negative terminal of Schottky barrier rectifier D2 and the other end of inductor L2, and the positive terminal of Schottky barrier rectifier D2 is grounded.

[0008] The charging circuit includes chip U2, resistor R5, capacitor C4, capacitor C5, and interface P1; the chip U2 is an MCP73831T; pin 2 of chip U2 is grounded; pin 3 of chip U2 and one end of capacitor C5 are electrically connected to pin 1 of interface P1, and the other end of capacitor C5 and pin 2 of interface P1 are grounded; pin 4 of chip U2 is electrically connected to one end of capacitor C4 and one end of inductor L2 connected to resistor R1, and the other end of capacitor C4 is grounded; pin 5 of chip U2 is electrically connected to one end of resistor R5, and the other end of resistor R5 is grounded.

[0009] The shutdown control circuit includes resistors R6, R7, and R8, and an NMOS transistor Q1. One end of resistor R6 and the drain (D) of NMOS transistor Q1 are electrically connected to pin 4 of chip U1, and the other end of resistor R6 is electrically connected to the negative terminal of Schottky barrier rectifier D1. One end of each of resistors R7 and R8 is electrically connected to the gate (G) of NMOS transistor Q1, and the other end of resistor R8 and the source (S) of NMOS transistor Q1 are grounded. The other end of resistor R7 is electrically connected to pin 1 of chip U2.

[0010] This solution is installed inside the device during use, with interface P1 electrically connected to the device's battery. When the device is placed on the wireless charging dock, the receiving coil L1 and capacitor C1 of the receiving circuit form an LC oscillation circuit, converting the alternating magnetic energy generated by the wireless charging dock into alternating current (AC) energy. This AC energy is then converted to direct current (DC) energy by the Schottky barrier rectifier D1. The voltage adjustment circuit uses chip U1, a step-down switching converter. After pin 5 of chip U1 is connected to the DC energy converted by the Schottky barrier rectifier D1, chip U1 will output voltage at pin 6. The voltage output from pin 6 is filtered by inductor L2 and capacitor C3 before being sent to pin 4 of chip U2. Chip U2 in the charging circuit is an advanced linear charging management controller. Pin 3 of chip U2 is connected to the positive terminal of the rechargeable battery. When chip U2 detects that the battery voltage has reached the charging threshold, it begins charging. When the battery is fully charged, pin 1 of chip U2 is high. At this time, resistor R7 in the control circuit turns on NMOS transistor Q1, causing pin 4 of chip U1 to go low, thus shutting down chip U1. With chip U1 off, chip U2 is also turned off. This design means that devices using this solution need to be detached from the wireless charging pad after being fully charged, and then placed back on the wireless charging pad to resume charging. Even after a device is fully charged, prolonged placement on the wireless charging pad will not cause repeated charging of the battery, protecting the battery and promoting energy conservation and environmental protection.

[0011] The preferred resistance range for resistor R1 is 124±5KΩ, and the preferred resistance range for resistor R2 is 23.7±1KΩ. The values ​​of resistors R1 and R2 are used to determine the voltage output from pin 6 of chip U1.

[0012] The preferred resistance value of resistor R5 is 2 ± 0.2 KΩ. The resistance value of resistor R5 is used to determine the magnitude of the charging current output from pin 3 of chip U2, and the magnitude of the charging current determines the charging time required.

[0013] This solution also includes a charging status indicator circuit; the charging status indicator circuit includes a resistor R4 and a light-emitting diode LED2; one end of the resistor R4 is electrically connected to the negative terminal of the Schottky barrier rectifier D1, and the other end of the resistor R4 is electrically connected to the positive terminal of the light-emitting diode LED2. The negative terminal of the light-emitting diode LED2 is electrically connected to pin 1 of the chip U2. During charging, pin 1 of the chip U2 is at a low level, causing the light-emitting diode LED2 to light up; after charging is complete, pin 1 of the chip U2 is at a high level, causing the light-emitting diode LED2 to turn off. This allows the user to know whether the electrical device is fully charged, which is very convenient to use.

[0014] This solution also includes a power status indicator circuit; the power status indicator circuit includes a resistor R3 and a light-emitting diode LED1; one end of the resistor R3 is electrically connected to the negative terminal of the Schottky barrier rectifier D1, and the other end of the resistor R3 is electrically connected to the positive terminal of the light-emitting diode LED1, with the negative terminal of LED1 grounded. In use, after the device is placed on the wireless charging pad, LED1 will light up immediately. If LED1 fails to light up, it indicates a fault in the receiving circuit.

[0015] To facilitate differentiation between LED2 and LED1 during use, the light-emitting color of LED2 is different from that of LED1.

[0016] Furthermore, interface P1 is preferably a lithium battery interface.

[0017] The advantages of this utility model are: simple structure, reasonable design, automatic power-off after the battery is fully charged, protection of the battery, and energy saving and environmental protection. Attached Figure Description

[0018] Figure 1 The circuit structure schematic diagram is shown in the embodiment.

[0019] Explanation of reference numerals in the attached diagram: 1-receiving circuit; 2-voltage adjustment circuit; 3-charging circuit; 4-shutdown control circuit; 5-charging status indicator circuit; 6-power status indicator circuit. Detailed Implementation

[0020] like Figure 1 As shown, a wireless charging receiving circuit for a wearable device according to this embodiment includes a receiving circuit 1, a voltage adjustment circuit 2, a charging circuit 3, and a shutdown control circuit 4; wherein:

[0021] The receiving circuit 1 includes a receiving coil L1, capacitors C1 and C2, and a Schottky barrier rectifier D1; one end of each of the receiving coil L1, capacitors C1 and C2 is grounded, the other end of each of the receiving coil L1 and capacitors C1 is electrically connected to the positive terminal of the Schottky barrier rectifier D1, and the other end of capacitor C2 is electrically connected to the negative terminal of the Schottky barrier rectifier D1.

[0022] The voltage adjustment circuit 2 includes chip U1, resistors R1 and R2, capacitor C3, Schottky barrier rectifier D2, and inductor L2. Chip U1 is a TX4137. Pin 1 of chip U1 is floating; pin 2 of chip U1 is grounded; pin 3 of chip U1 is electrically connected to one end of each of resistors R1 and R2, and the other end of resistor R1 and one end of capacitor C3 are both electrically connected to one end of inductor L2. The other ends of resistor R2 and capacitor C3 are both grounded; pin 5 of chip U1 is electrically connected to the negative terminal of Schottky barrier rectifier D1; pin 6 of chip U1 is electrically connected to the negative terminal of Schottky barrier rectifier D2 and the other end of inductor L2, and the positive terminal of Schottky barrier rectifier D2 is grounded.

[0023] The charging circuit 3 includes chip U2, resistor R5, capacitor C4, capacitor C5, and interface P1; the chip U2 is model MCP73831T; pin 2 of chip U2 is grounded, pin 3 of chip U2 and one end of capacitor C5 are electrically connected to pin 1 of interface P1, and the other end of capacitor C5 and pin 2 of interface P1 are grounded; interface P1 is a lithium battery interface; pin 4 of chip U2 is electrically connected to one end of capacitor C4 and the end of inductor L2 connected to resistor R1, and the other end of capacitor C4 is grounded; pin 5 of chip U2 is electrically connected to one end of resistor R5, and the other end of resistor R5 is grounded.

[0024] The shutdown control circuit 4 includes resistors R6, R7, and R8, and an NMOS transistor Q1. One end of resistor R6 and the drain (D) of NMOS transistor Q1 are electrically connected to pin 4 of chip U1, and the other end of resistor R6 is electrically connected to the negative terminal of Schottky barrier rectifier D1. One end of each of resistors R7 and R8 is electrically connected to the gate (G) of NMOS transistor Q1, and the other end of resistor R8 and the source (S) of NMOS transistor Q1 are grounded. The other end of resistor R7 is electrically connected to pin 1 of chip U2. The NMOS transistor Q1 is a CJBA3134K. With this design, devices using this wireless charging receiver circuit need to be separated from the wireless charging pad after being fully charged, and then placed back on the wireless charging pad to resume charging. Even after a device is fully charged, prolonged placement on the wireless charging pad will not cause repeated charging of the battery, thus protecting the battery and promoting energy conservation and environmental protection.

[0025] like Figure 1 As shown, resistor R1 has a resistance of 124KΩ, and resistor R2 has a resistance of 23.7KΩ. This design ensures that pin 6 of chip U1 outputs a voltage of 5V, which meets the requirements of this wireless charging receiver circuit.

[0026] like Figure 1As shown, the resistance of resistor R5 is 2KΩ. This design allows the charging current output from pin 3 of chip U2 to be 500mA, ensuring that this wireless charging receiver circuit can meet the charging needs of the wearable medical device's battery while avoiding damage to the battery due to excessive charging current.

[0027] like Figure 1 As shown, this wireless charging receiver circuit also includes a charging status indicator circuit 5; the charging status indicator circuit 5 includes a resistor R4 and a light-emitting diode LED2; one end of the resistor R4 is electrically connected to the negative terminal of the Schottky barrier rectifier D1, and the other end of the resistor R4 is electrically connected to the positive terminal of the light-emitting diode LED2. The negative terminal of the light-emitting diode LED2 is electrically connected to pin 1 of the chip U2. During charging, pin 1 of the chip U2 is at a low level, causing the light-emitting diode LED2 to light up; after charging is completed, pin 1 of the chip U2 is at a high level, causing the light-emitting diode LED2 to turn off; this allows the user to know whether the device is fully charged, which is very convenient to use.

[0028] like Figure 1 As shown, this wireless charging receiver circuit also includes a power status indicator circuit 6; the power status indicator circuit 6 includes a resistor R3 and a light-emitting diode LED1; one end of the resistor R3 is electrically connected to the negative terminal of the Schottky barrier rectifier D1, and the other end of the resistor R3 is electrically connected to the positive terminal of the light-emitting diode LED1, with the negative terminal of the light-emitting diode LED1 grounded. In use, after the device is placed on the wireless charging pad, the light-emitting diode LED1 will light up immediately. If the light-emitting diode LED1 fails to light up, it indicates a fault in the receiver circuit 1.

[0029] To facilitate distinguishing between LED2 and LED1 during use, such as Figure 1 As shown, the light-emitting color of LED2 is different from that of LED1.

Claims

1. A wireless charging receiver circuit for a wearable device, characterized in that: It includes a receiving circuit, a voltage regulation circuit, a charging circuit, and a shutdown control circuit; wherein: The receiving circuit includes a receiving coil L1, capacitors C1 and C2, and a Schottky barrier rectifier D1; one end of each of the receiving coil L1, capacitors C1 and C2 is grounded, the other end of each of the receiving coil L1 and capacitors C1 is electrically connected to the positive terminal of the Schottky barrier rectifier D1, and the other end of capacitor C2 is electrically connected to the negative terminal of the Schottky barrier rectifier D1. The voltage adjustment circuit includes chip U1, resistors R1 and R2, capacitor C3, Schottky barrier rectifier D2, and inductor L2. Chip U1 is a TX4137. Pin 1 of chip U1 is floating; pin 2 of chip U1 is grounded; pin 3 of chip U1 is electrically connected to one end of each of resistors R1 and R2, and the other end of resistor R1 and one end of capacitor C3 are both electrically connected to one end of inductor L2. The other ends of resistor R2 and capacitor C3 are both grounded; pin 5 of chip U1 is electrically connected to the negative terminal of Schottky barrier rectifier D1; pin 6 of chip U1 is electrically connected to the negative terminal of Schottky barrier rectifier D2 and the other end of inductor L2, and the positive terminal of Schottky barrier rectifier D2 is grounded. The charging circuit includes chip U2, resistor R5, capacitor C4, capacitor C5, and interface P1; the chip U2 is an MCP73831T; pin 2 of chip U2 is grounded; pin 3 of chip U2 and one end of capacitor C5 are electrically connected to pin 1 of interface P1, and the other end of capacitor C5 and pin 2 of interface P1 are grounded; pin 4 of chip U2 is electrically connected to one end of capacitor C4 and one end of inductor L2 connected to resistor R1, and the other end of capacitor C4 is grounded; pin 5 of chip U2 is electrically connected to one end of resistor R5, and the other end of resistor R5 is grounded. The shutdown control circuit includes resistors R6, R7, and R8, and an NMOS transistor Q1. One end of resistor R6 and the drain (D) of NMOS transistor Q1 are electrically connected to pin 4 of chip U1, and the other end of resistor R6 is electrically connected to the negative terminal of Schottky barrier rectifier D1. One end of each of resistors R7 and R8 is electrically connected to the gate (G) of NMOS transistor Q1, and the other end of resistor R8 and the source (S) of NMOS transistor Q1 are grounded. The other end of resistor R7 is electrically connected to pin 1 of chip U2.

2. The wireless charging receiver circuit for a wearable device according to claim 1, characterized in that: The resistance value of resistor R1 is 124±5KΩ, and the resistance value of resistor R2 is 23.7±1KΩ.

3. The wireless charging receiver circuit for a wearable device according to claim 1, characterized in that: The resistance value of resistor R5 is 2 ± 0.2 KΩ.

4. The wireless charging receiver circuit for a wearable device according to claim 1, characterized in that: It also includes a charging status indicator circuit; the charging status indicator circuit includes a resistor R4 and a light-emitting diode LED2; one end of the resistor R4 is electrically connected to the negative terminal of the Schottky barrier rectifier D1, the other end of the resistor R4 is electrically connected to the positive terminal of the light-emitting diode LED2, and the negative terminal of the light-emitting diode LED2 is electrically connected to pin 1 of the chip U2.

5. The wireless charging receiver circuit for a wearable device according to claim 4, characterized in that: It also includes a power status indicator circuit; the power status indicator circuit includes a resistor R3 and a light-emitting diode LED1; one end of the resistor R3 is electrically connected to the negative terminal of the Schottky barrier rectifier D1, the other end of the resistor R3 is electrically connected to the positive terminal of the light-emitting diode LED1, and the negative terminal of the light-emitting diode LED1 is grounded.

6. The wireless charging receiver circuit for a wearable device according to claim 5, characterized in that: The light-emitting color of LED2 is different from that of LED1.

7. The wireless charging receiver circuit for a wearable device according to claim 1, characterized in that: Interface P1 is the lithium battery interface.

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