Charging circuit and capacitance pen

Abstract

The utility model relates to the technical field of wireless charging, and discloses a charging circuit and a capacitive stylus, the charging circuit comprises a wireless charging unit, a charging chip and a switch unit, the input end of the wireless charging unit inputs an external electromagnetic signal, the output end of the wireless charging unit is connected with the input end of the charging chip and the first end of the switch unit, and the first end of the switch unit is connected with the charging chip. The wireless charging unit is used for converting the electromagnetic signal into a voltage signal and outputting the voltage signal; the output end of the charging chip is connected with the second end of the switch unit and the power supply end of the battery, and the charging chip is used for charging the battery based on the voltage signal. The charging mode can be switched according to the battery voltage, and the charging efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to wireless charging technical field, concretely relates to a charging circuit and electric capacity pen. BACKGROUND

[0002] With the development of intelligent terminal, wireless charging electric capacity pen also rises, in order to meet the portable requirement, the internal battery capacity of wireless charging electric capacity pen is small, and there is a certain limit to the time of use, and since electromagnetic energy has certain loss in transmission process, the energy transmission efficiency of wireless charging is usually lower than wired charging, leading to relatively slow charging speed of wireless charging under the same input power. SUMMARY

[0003] Therefore, the technical problem to be solved by the utility model lies in solving the problem of low wireless charging efficiency in the prior art, thereby providing a charging circuit and electric capacity pen.

[0004] To achieve the above object, the utility model provides the following technical scheme:

[0005] Firstly, the utility model provides a charging circuit, which comprises a wireless charging unit, a charging chip and a switching unit, wherein the input end of the wireless charging unit inputs an external electromagnetic signal, the output end of the wireless charging unit is connected with the input end of the charging chip and the first end of the switching unit, and the wireless charging unit is used to output a voltage signal after converting the electromagnetic signal; the output end of the charging chip is connected with the second end of the switching unit and the power supply end of the battery, and the charging chip is used to charge the battery based on the voltage signal; when the voltage of the power supply end of the battery is lower than a preset voltage, the switching unit is turned on, the charging chip stops working, and the wireless charging unit directly charges the battery through the switching unit.

[0006] The charging circuit provided by the utility model directly charges the battery through the switching unit when the battery voltage is lower than the preset voltage and needs to be quickly charged, thereby improving the charging efficiency. When the charging circuit takes power from the host computer, the charging circuit of the utility model can reduce the consumption of the host computer power under the condition of charging the same battery capacity.

[0007] In an alternative embodiment, the wireless charging unit comprises a receiving unit and a signal processing unit, wherein the input end of the receiving unit inputs an external electromagnetic signal, the output end of the receiving unit is connected with the input end of the signal processing unit, and the receiving unit is used to convert the electromagnetic signal into an alternating current signal; the output end of the signal processing unit is connected with the input end of the charging chip, and the signal processing unit is used to output a direct current voltage signal after rectifying and filtering the alternating current signal.

[0008] In an alternative embodiment, the signal processing unit comprises a rectifying unit and a filtering unit, wherein the input end of the rectifying unit is connected with the output end of the receiving unit, the output end of the rectifying unit is connected with the input end of the filtering unit, the rectifying unit is used for rectifying the alternating current signal into a direct current signal; the output end of the filtering unit is connected with the input end of the charging chip, and the filtering unit is used for filtering out the interference in the direct current signal.

[0009] The charging circuit provided by the utility model can further improve the charging efficiency of the battery by filtering the direct current signal.

[0010] In an alternative embodiment, the switch unit comprises a controllable switch, wherein the first end of the controllable switch is connected with the output end of the wireless charging unit, and the second end of the controllable switch is connected with the power supply end of the battery; when the voltage of the power supply end of the battery is greater than or equal to the preset voltage, the controllable switch is turned off, and the wireless charging unit charges the battery through the charging chip; when the voltage of the power supply end of the battery is lower than the preset voltage, the controllable switch is turned on, and the wireless charging unit directly charges the battery through the controllable switch.

[0011] In an alternative embodiment, the charging circuit further comprises a control unit, wherein the input end of the control unit is connected with the first output end of the charging chip, the output end of the control unit is connected with the control end of the switch unit, and the second output end of the control unit is connected with the control end of the wireless charging unit; the control unit is used for adjusting the size of the voltage signal output by the wireless charging unit according to the voltage of the power supply end of the battery, and controlling the switch unit to switch the on-off state based on the size of the voltage of the power supply end of the battery and the preset voltage.

[0012] The control unit of the charging circuit can dynamically adjust the voltage output by the wireless charging unit according to the voltage of the power supply end of the battery, thereby improving the charging efficiency.

[0013] In an alternative embodiment, the charging circuit further comprises a detection unit, wherein the input end of the detection unit is connected with the output end of the charging chip, the output end of the detection unit is connected with the control end of the wireless charging unit, and the detection unit is used for dynamically feeding back the electrical parameter of the power supply end of the battery to the wireless charging unit; when the voltage of the power supply end of the battery is lower than the preset voltage, the switch unit is turned on, the charging chip stops working, and the wireless charging unit directly charges the battery through the switch unit.

[0014] In an alternative embodiment, the detection unit comprises: a voltage detection circuit, a current detection circuit, a charging temperature detection circuit and a metering chip, wherein the input end of the voltage detection circuit is connected with the output end of the charging chip, the output end of the voltage detection circuit is connected with the first end of the current detection circuit and the first end of the metering chip, the second end of the voltage detection circuit is connected with the second end of the current detection circuit, the first end of the charging temperature detection circuit and the ground end of the metering chip, the voltage detection circuit is used for collecting the voltage of the output end of the charging chip; the third end of the current detection circuit is connected with the second end of the metering chip, the current detection circuit is used for collecting the charging current of the battery; the second end of the charging temperature detection circuit is connected with the third end of the metering chip, the third end of the charging temperature detection circuit is connected with the fourth end of the metering chip, the charging temperature detection circuit is used for collecting the temperature of the battery; the output end of the metering chip is connected with the control end of the wireless charging unit, the metering chip is used for sending the voltage of the output end of the charging chip, the charging current of the battery and the temperature of the battery to the wireless charging unit.

[0015] In an alternative embodiment, the charging temperature detection circuit comprises a thermistor, a first resistor and a first capacitor, wherein the first end of the thermistor and the first end of the first capacitor are both connected with the ground end of the metering chip, the second end of the thermistor and the second end of the first capacitor are both connected with the first end of the first resistor and the third end of the metering chip; the second end of the first resistor is connected with the fourth end of the metering chip.

[0016] In an alternative embodiment, the voltage detection circuit and the current detection circuit both comprise a sampling resistor.

[0017] In a second aspect, the utility model provides a capacitive pen, comprising: capacitive pen body and the charging circuit of first aspect, charging circuit is integrated in the inside of capacitive pen body.

[0018] The capacitive pen provided by the utility model can reduce the consumption of the host computer power when the capacitive pen takes power from the host computer under the condition that the same battery capacity is fully charged. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the utility model or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description, and obviously, the drawings in the following description are some embodiments of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without creating creative labor.

[0020] Figure 1A component diagram of one specific example of the charging circuit of the embodiment of the utility model;

[0021] Figure 2 A component diagram of one specific example of the wireless charging unit of the embodiment of the utility model;

[0022] Figure 3 A component diagram of another specific example of the charging circuit of the embodiment of the utility model;

[0023] Figure 4 A component diagram of another specific example of the charging circuit of the embodiment of the utility model;

[0024] Figure 5 A structure diagram of one specific circuit of the detection unit of the embodiment of the utility model;

[0025] Explanation of reference signs:

[0026] 1: wireless charging unit; 2: charging chip; 3: switch unit; 4: control unit; 5: detection unit;

[0027] 11: receiving unit; 12: signal processing unit;

[0028] 51: voltage detection circuit; 52: current detection circuit; 53: charging temperature detection circuit; 54: metering chip;

[0029] 121: rectifier unit; 122: filter unit. DETAILED DESCRIPTION

[0030] The technical scheme of the utility model will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0031] In the description of the utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; they may refer to internal connections between two components; they may refer to wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0033] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] This embodiment provides a charging circuit, such as Figure 1 As shown, it includes: a wireless charging unit 1, a charging chip 2 and a switch unit 3.

[0035] Figure 1 In the figure, the input end of the wireless charging unit 1 inputs an external electromagnetic signal, the output end of the wireless charging unit 1 is connected to the input end of the charging chip 2 and the first end of the switch unit 3, and the wireless charging unit 1 is used to convert the electromagnetic signal into a voltage signal and then output it.

[0036] Specifically, Figure 1 In the wireless charging unit 1, a coil is included inside. When there is an electromagnetic signal, an alternating magnetic field is generated in the coil through electromagnetic induction, and then an induced current and an induced voltage are generated, thereby outputting a voltage signal.

[0037] Optionally, the wireless charging unit 1 may use a linear charging chip that can stably output a DC signal.

[0038] Figure 1 In the embodiment, the output end of the charging chip 2 is connected to the second end of the switch unit 3 and the power supply end of the battery, and the charging chip 2 is used to charge the battery based on the voltage signal.

[0039] Specifically, Figure 1 During the charging process, the charging chip 2 continuously monitors battery voltage, current, and temperature, and makes judgments and adjustments through internal control logic. If it detects conditions such as excessively high or low battery voltage, excessively high or low current, or abnormal temperature, the charging chip 2 will stop or adjust the charging process to protect the safety and life of the battery.

[0040] Specifically, Figure 1In the embodiment, the switch unit 3 can be internally provided with a voltage comparator. When the voltage at the power supply end of the battery is greater than or equal to a preset voltage of the voltage comparator, it indicates that the battery has a relatively sufficient power at this time, and then the switch unit 3 is turned off, so that the charging chip 2 normally charges the battery based on the voltage signal output by the wireless charging unit 1. When the voltage at the power supply end of the battery is lower than the preset voltage, it indicates that the battery has a very low power at this time and needs to be quickly charged, and then the switch unit 3 is turned on, so that the charging chip 2 is short-circuited to stop working, and the voltage signal of the wireless charging unit 1 is directly input to the power supply end of the battery through the switch unit 3 to directly charge the battery, thereby improving the charging efficiency.

[0041] It should be noted that the charging chip in the embodiment is a mature charging control logic disclosed by the prior art, and the dynamic adjustment of the charging process of the battery will not be described here.

[0042] It should be noted that the person skilled in the art can also set the charging circuit to charge the battery while the wireless charging unit directly charges the battery through the switch unit when the battery has a very low power, thereby further improving the charging efficiency.

[0043] The charging circuit provided in the embodiment directly charges the battery through the switch unit when the battery voltage is lower than the preset voltage and needs to be quickly charged, thereby improving the charging efficiency. When the charging circuit takes power from the host, the charging circuit can reduce the consumption of the power of the host under the condition that the same battery capacity is fully charged.

[0044] In some optional embodiments, as shown in Figure 2 The wireless charging unit 1 includes a receiving unit 11 and a signal processing unit 12. The input end of the receiving unit 11 inputs an external electromagnetic signal. The output end of the receiving unit 11 is connected with the input end of the signal processing unit 12. The receiving unit 11 is used to convert the electromagnetic signal into an alternating current signal. The output end of the signal processing unit 12 is connected with the input end of the charging chip 2. The signal processing unit 12 is used to rectify and filter the alternating current signal to output a direct current voltage signal.

[0045] Specifically, Figure 2 The signal processing unit 12 includes a rectifying unit 121 and a filtering unit 122. The input end of the rectifying unit 121 is connected with the output end of the receiving unit 11. The output end of the rectifying unit 121 is connected with the input end of the filtering unit 122. The rectifying unit 121 is used to rectify the alternating current signal into a direct current signal. The output end of the filtering unit 122 is connected with the input end of the charging chip 2. The filtering unit 122 is used to filter out the interference in the direct current signal.

[0046] Optionally, as shown in Figure 2In the specific implementation, the switch unit 3 comprises a controllable switch, wherein the controllable switch can be a MOS tube, a relay switch, etc., a first end of the controllable switch is connected with an output end of the wireless charging unit 1, a second end of the controllable switch is connected with a power supply end of the battery, and a control end of the controllable switch can be connected with a voltage comparator, one input end of the voltage comparator inputs a preset voltage, and the other input end is connected with the power supply end of the battery; when the voltage of the power supply end of the battery is greater than or equal to the preset voltage, the controllable switch is turned off, and the wireless charging unit 1 charges the battery through the charging chip 2; when the voltage of the power supply end of the battery is lower than the preset voltage, the controllable switch is turned on, and the wireless charging unit 1 directly charges the battery through the controllable switch.

[0047] In some optional embodiments, as shown in Figure 3 The charging circuit further comprises a control unit 4, wherein an input end of the control unit 4 is connected with a first output end of the charging chip 2, an output end of the control unit 4 is connected with a control end of the switch unit 3, and a second output end of the control unit 4 is connected with a control end of the wireless charging unit 1; the control unit 4 is used for adjusting the size of the voltage signal output by the wireless charging unit 1 according to the voltage of the power supply end of the battery, and controlling the switch unit 3 to switch the on-off state based on the size of the voltage of the power supply end of the battery and the preset voltage.

[0048] Specifically, Figure 3 In the specific implementation, the control unit 4 pre-stores the preset voltage, the control unit 4 collects the voltage of the power supply end of the battery and compares it with the preset voltage. When the control unit 4 determines that the voltage of the power supply end of the battery is greater than or equal to the preset voltage, it indicates that the battery has a relatively sufficient power at this time, and then the control unit 4 controls the switch unit 3 to be turned off, so that the charging chip 2 normally charges the battery based on the voltage signal output by the wireless charging unit 1. When the control unit 4 determines that the voltage of the power supply end of the battery is lower than the preset voltage, it indicates that the battery has a very low power at this time and needs to be quickly charged, and then the control unit 4 controls the switch unit 3 to be turned on, so that the charging chip 2 is short-circuited and stops working, and the voltage signal of the wireless charging unit 1 is directly input to the power supply end of the battery through the switch unit 3 to directly charge the battery, thereby improving the charging efficiency.

[0049] It should be noted that the method of determining the power of the battery by the control unit according to the output voltage of the battery and the method of controlling the switch unit to switch the on-off state by the control unit according to the power of the battery in the present embodiment are both relatively mature control methods in the prior art, and the present embodiment only protects the structure of the charging circuit and does not protect the charging control method.

[0050] In some optional embodiments, as shown in Figure 4 The charging circuit further comprises a detection unit 5, wherein an input end of the detection unit is connected with an output end of the charging chip 2, an output end of the detection unit is connected with a control end of the wireless charging unit 1, and the detection unit is used for dynamically feeding back the voltage of the power supply end of the battery to the wireless charging unit 1.

[0051] Specifically, Figure 3 In the specific embodiment, the detection unit 5 is configured to collect the voltage of the battery supply end and send the dynamic change process of the voltage to the wireless charging unit 1 in real time, so that the wireless charging unit 1 adjusts the output voltage according to the change of the voltage of the battery supply end. For example, when the voltage of the battery supply end is high, the wireless charging unit 1 reduces the size of the output voltage, so that the wireless charging unit 1 buffers the battery through the charging chip 2; when the voltage of the battery supply end is low, the wireless charging unit 1 increases the size of the output voltage, so that the wireless charging unit 1 fast charges the battery through the charging chip 2.

[0052] Specifically, Figure 3 In the specific embodiment, the detection unit 5 is further configured to compare the voltage of the battery supply end with a preset voltage. When it is determined that the voltage of the battery supply end is lower than the preset voltage, the switching unit 3 is turned on, the charging chip 2 stops working, and the wireless charging unit 1 directly charges the battery through the switching unit 3. When it is determined that the voltage of the battery supply end is greater than or equal to the preset voltage, the switching unit 3 is turned off, the charging chip 2 starts working, and the wireless charging unit 1 charges the battery through the charging chip 2.

[0053] Optionally, with reference to Figure 3 and Figure 4 The output end of the detection unit 5 can also be connected with the input end of the control unit 4, the first output end of the control unit 4 is connected with the control end of the wireless charging unit 1, and the second output end of the control unit 4 is connected with the control end of the switching unit 3. When the detection unit 5 determines that the voltage of the battery supply end is lower than the preset voltage, the detection unit 5 outputs a first level signal to the control unit 4, so that the control unit 4 controls the switching unit 3 to be turned on, the charging chip 2 stops working, and the wireless charging unit 1 directly charges the battery through the switching unit 3. When it is determined that the voltage of the battery supply end is greater than or equal to the preset voltage, the detection unit 5 outputs a second level signal to the control unit 4, so that the control unit 4 controls the switching unit 3 to be turned off, the charging chip 2 starts working, and the wireless charging unit 1 charges the battery through the charging chip 2.

[0054] In an optional embodiment, as Figure 5As shown, the detection unit 5 comprises a voltage detection circuit 51, a current detection circuit 52, a charging temperature detection circuit 53 and a metering chip 54, wherein the input end of the voltage detection circuit 51 is connected with the output end of the charging chip, the output end of the voltage detection circuit 51 is connected with the first end of the current detection circuit 52 and the first end of the metering chip 54, the second end of the voltage detection circuit 51 is connected with the second end of the current detection circuit 52, the first end of the charging temperature detection circuit 53 and the ground end of the metering chip 54; the third end of the current detection circuit 52 is connected with the second end of the metering chip 54; the second end of the charging temperature detection circuit 53 is connected with the third end of the metering chip 54, and the third end of the charging temperature detection circuit 53 is connected with the fourth end of the metering chip 54; the output end (i.e. IIC4_SDA end and IIC4_SCL end) of the metering chip 54 is connected with the input end of the control end of the wireless charging unit 1.

[0055] Specifically, Figure 4 In the charging temperature detection circuit 53, a thermistor RT602, a first resistor R604 and a first capacitor C605 are included, wherein the first end of the thermistor RT602 and the first end of the first capacitor C605 are both connected with the ground end (i.e. VSS end) of the metering chip 54, the second end of the thermistor RT602 and the second end of the first capacitor C605 are both connected with the first end of the first resistor R604 and the third end of the metering chip 54; the second end of the first resistor R604 is connected with the fourth end of the metering chip 54. The thermistor RT602 is arranged close to the battery, which can change the resistance value according to the temperature change of the battery, so as to change the voltage drop across the thermistor RT602, and the metering chip 54 can judge the battery temperature by reading the voltage across the thermistor RT602.

[0056] Specifically, Figure 4 In the voltage detection circuit 51, a sampling resistor R616 and a filter capacitor C632 are included, the sampling resistor R616 generates a voltage drop based on the voltage of the output end of the charging chip, and then the sampling resistor R616 sends the voltage signal to the metering chip 54; in the current detection circuit 52, a sampling resistor R603 and a filter capacitor C604 are included, the charging current of the battery passes through the sampling resistor R603 and generates a voltage drop on the R603, and then the sampling resistor R603 outputs the corresponding voltage signal to the metering chip 54. The metering chip 54 is used to send the voltage of the output end of the charging chip, the charging current of the battery and the temperature of the battery to the wireless charging unit 1.

[0057] The embodiment provides a capacitive pen, which comprises: a capacitive pen body and a charging circuit of the first aspect, the charging circuit is integrated in the inside of the capacitive pen body; and a charging interface is further arranged on the surface of the capacitive pen body and electrically connected with a battery.

[0058] Specifically, the capacitive pen is usually based on magnetic induction technology to be adsorbed on the host for charging, and the coil of the host end generates a changing magnetic field, so that the wireless charging unit 1 in the capacitive pen body generates electric energy based on electromagnetic induction. When the host power is low, the capacitive pen body can be charged through the charging interface and the external charger in a wired connection, avoiding additional consumption of the host power.

[0059] The capacitive pen provided by the embodiment can directly charge the battery of the capacitive pen through the switching unit through the wireless charging unit when the battery voltage is lower than the preset voltage and needs to be quickly charged, thereby improving the charging efficiency. When the capacitive pen takes power through the host, the capacitive pen can reduce the consumption of the host power under the condition that the same battery capacity is fully charged.

[0060] Although the embodiments of the utility model are described in combination with the drawings, various modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the utility model, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A charging circuit, characterized in that: include: Wireless charging unit, charging chip and switch unit, wherein, The input end of the wireless charging unit inputs an external electromagnetic signal, the output end of the wireless charging unit is connected to the input end of the charging chip and the first end of the switch unit, and the wireless charging unit is used to convert the electromagnetic signal into a voltage signal and output it; The output end of the charging chip is connected to the second end of the switch unit and the power supply end of the battery, and the charging chip is used to charge the battery based on the voltage signal; When the voltage of the power supply terminal of the battery is lower than a preset voltage, the switch unit is turned on, the charging chip stops working, and the wireless charging unit directly charges the battery through the switch unit.

2. The charging circuit according to claim 1, wherein: The wireless charging unit includes: a receiving unit and a signal processing unit, wherein: The input end of the receiving unit inputs an external electromagnetic signal, the output end of the receiving unit is connected to the input end of the signal processing unit, and the receiving unit is used to convert the electromagnetic signal into an alternating current signal; The output end of the signal processing unit is connected to the input end of the charging chip, and the signal processing unit is used to rectify and filter the AC signal and then output a DC voltage signal.

3. The charging circuit according to claim 2, wherein: The signal processing unit includes: a rectification unit and a filtering unit, wherein: The input end of the rectifier unit is connected to the output end of the receiving unit, the output end of the rectifier unit is connected to the input end of the filtering unit, and the rectifier unit is used to rectify the AC signal into a DC signal; The output end of the filter unit is connected to the input end of the charging chip, and the filter unit is used to filter out interference in the DC signal.

4. The charging circuit according to claim 1, wherein: The switch unit includes: a controllable switch, wherein: The first end of the controllable switch is connected to the output end of the wireless charging unit, and the second end of the controllable switch is connected to the power supply end of the battery; When the voltage at the power supply terminal of the battery is greater than or equal to a preset voltage, the controllable switch is disconnected, and the wireless charging unit charges the battery through the charging chip; When the voltage of the power supply terminal of the battery is lower than a preset voltage, after the controllable switch is turned on, the wireless charging unit directly charges the battery through the controllable switch.

5. The charging circuit according to claim 1, wherein: Also includes: a control unit, wherein The input end of the control unit is connected to the first output end of the charging chip, the output end of the control unit is connected to the control end of the switch unit, and the second output end of the control unit is connected to the control end of the wireless charging unit; The control unit is used to adjust the magnitude of the voltage signal output by the wireless charging unit according to the magnitude of the voltage at the power supply end of the battery, and control the switching unit to switch on and off based on the magnitude of the power supply end voltage of the battery and the preset voltage.

6. The charging circuit according to claim 1, wherein: Also includes: Detection unit, wherein The input end of the detection unit is connected to the output end of the charging chip, and the output end of the detection unit is connected to the control end of the wireless charging unit. The detection unit is used to dynamically feed back the electrical parameters of the battery power supply end to the wireless charging unit; When the voltage of the power supply terminal of the battery is lower than a preset voltage, the switch unit is turned on, the charging chip stops working, and the wireless charging unit directly charges the battery through the switch unit.

7. The charging circuit according to claim 6, characterized in that: The detection unit includes: a voltage detection circuit, a current detection circuit, a charging temperature detection circuit and a metering chip, wherein: The input end of the voltage detection circuit is connected to the output end of the charging chip, the output end of the voltage detection circuit is connected to the first end of the current detection circuit and the first end of the metering chip, the second end of the voltage detection circuit is connected to the second end of the current detection circuit, the first end of the charging temperature detection circuit, and the ground end of the metering chip, and the voltage detection circuit is used to collect the voltage at the output end of the charging chip; The third terminal of the current detection circuit is connected to the second terminal of the metering chip, and the current detection circuit is used to collect the charging current of the battery; The second end of the charging temperature detection circuit is connected to the third end of the metering chip, and the third end of the charging temperature detection circuit is connected to the fourth end of the metering chip. The charging temperature detection circuit is used to collect the temperature of the battery; The output end of the metering chip is connected to the control end of the wireless charging unit, and the metering chip is used to send the voltage of the output end of the charging chip, the charging current of the battery, and the temperature of the battery to the wireless charging unit.

8. The charging circuit according to claim 7, characterized in that: The charging temperature detection circuit includes: a thermistor, a first resistor and a first capacitor, wherein: The first end of the thermistor and the first end of the first capacitor are both connected to the ground terminal of the metering chip, and the second end of the thermistor and the second end of the first capacitor are both connected to the first end of the first resistor and the third end of the metering chip; The second end of the first resistor is connected to the fourth end of the metering chip.

9. The charging circuit according to claim 7, wherein: The voltage detection circuit and the current detection circuit both include sampling resistors.

10. A capacitive stylus, characterized in that: include: A capacitive stylus body and a charging circuit according to any one of claims 1 to 9, wherein the charging circuit is integrated inside the capacitive stylus body.

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