Charging circuit, capacitance pen and charging system

Abstract

The utility model discloses a charging circuit, a capacitive stylus and a charging system, and relates to the technical field of capacitive stylus charging, the charging circuit comprises a wireless charging receiving circuit, the wireless charging receiving circuit is internally provided with a receiving coil, and the receiving coil is used for receiving magnetic flux sent by a wireless charging transmitting device and converting the magnetic flux into direct current electric energy; the charging management circuit is used for converting the received direct-current electric energy of the wireless charging receiving circuit and then charging the battery, and is used for managing the charging state and the discharging state of the battery; the charging control circuit is used for collecting electric quantity information of the battery and is also used for controlling the charging management circuit to stop charging the battery and stop sending electric energy of the battery to the charging control circuit when the battery is in a charging state and the battery is detected to be fully charged according to the electric quantity information of the charging management circuit; and the direct current electric energy output by the wireless charging receiving circuit is received, converted and then supplied to a load. Therefore, the problem of repeated charging of the capacitance pen battery can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of capacitive pen charging, in particular to a charging circuit, a capacitive pen and a charging system. Background Art

[0002] When the capacitive pen is wirelessly charged, the wireless charging function needs to be turned off when the battery of the capacitive pen is fully charged. However, the load inside the capacitive pen (such as the LED light indicating the charging status) still needs to extract power from the battery for use. This often results in the capacitive pen starting to charge again after the load has used up a certain amount of power. This repeated charging phenomenon greatly shortens the life of the battery inside the capacitive pen. Utility Model Content

[0003] The main purpose of the utility model is to provide a charging circuit, a capacitive stylus and a charging system, which are intended to solve the problem that when a capacitive stylus is wirelessly charged, the capacitive stylus still needs to extract power from the battery inside the capacitive stylus due to the load inside the capacitive stylus (such as an LED light indicating the charging status). This often causes the capacitive stylus to start charging again after the load has used up a certain amount of power.

[0004] To achieve the above-mentioned object, the charging circuit proposed in the present invention is applied to a capacitive stylus. The capacitive stylus is provided with a battery and a load. The charging circuit includes:

[0005] A wireless charging receiving circuit, wherein a receiving coil is provided in the wireless charging receiving circuit, and the wireless charging receiving circuit is electrically connected to the charging control circuit, and is used to convert the magnetic flux sent by the wireless charging transmitting device into DC power;

[0006] a charging management circuit, the charging management circuit being electrically connected to the battery and the wireless charging receiving circuit, the charging management circuit being configured to convert direct current power received from the wireless charging receiving circuit and then charge the battery, the charging management circuit being configured to manage the charging and discharging states of the battery, and to collect battery power information;

[0007] A charging control circuit, wherein the charging control circuit is electrically connected to the charging management circuit and the wireless charging receiving circuit respectively; the charging control circuit is used to collect battery power information. The charging control circuit is used to control the charging management circuit to stop charging the battery and stop sending battery power to the charging control circuit when the battery is in a charging state and detects that the battery is fully charged according to the battery power information of the charging management circuit; and receive the DC power output by the wireless charging receiving circuit, and convert the DC power to supply power to the load.

[0008] In one embodiment, the charging control circuit is used to control the charging management circuit to send battery power to the charging control circuit when the battery is in a charging state and detects that the battery is not fully charged based on the power information of the charging management circuit, so as to receive the battery power output by the charging management circuit and convert the battery power to supply power to the load.

[0009] In one embodiment, the charging management circuit includes:

[0010] a switch circuit, for controlling the charging state of the battery and the state of sending battery power to the load;

[0011] A charging management chip is electrically connected to the switching circuit, the charging management chip is electrically connected to the wireless charging receiving circuit, and the charging management chip is electrically connected to the charging control circuit, and is used to control the switching circuit to be cut off or turned on.

[0012] In one embodiment, the charging circuit further includes:

[0013] A protection circuit is electrically connected to the battery and the charging management circuit, and is used to prevent the battery from being overcharged and over-discharged.

[0014] In one embodiment, a step-down circuit is integrated in the charging control circuit, and the step-down circuit is used to step down the voltage of the electric energy received by the charging control circuit and then supply power to the load.

[0015] In one embodiment, the charging circuit includes:

[0016] A USB charging circuit is electrically connected to the charging control circuit and is used to connect to a USB port. The USB charging circuit is used to receive external power from the USB port and send it to the charging control circuit to control the charging control circuit to charge the battery.

[0017] In one embodiment, the USB charging circuit is electrically connected to an external power source through a USB port, and the USB port includes any one or more of a Type-A interface, a Type-B interface, a Type-C interface, a miniUSB interface, and a microUSB interface.

[0018] In one embodiment, the number of the loads is more than one.

[0019] In one embodiment, the load includes a Hall switch, a button, an LED light, a gesture sensor, and an image sensor.

[0020] The present invention also provides a capacitive stylus, which includes the charging circuit described above.

[0021] The present invention further provides a charging system, which includes a wireless charging transmitter, a USB charger, and the capacitive stylus as described above.

[0022] The technical solution of the present utility model adopts a charging circuit, which is applied to a capacitive stylus. The capacitive stylus is provided with a battery and a load. The charging circuit includes: a wireless charging receiving circuit, in which a receiving coil is provided, and the wireless charging receiving circuit is electrically connected to the charging control circuit, and is used to convert the magnetic flux sent by the wireless charging transmitting device into direct current power; a charging management circuit, which is electrically connected to the battery and the charging management circuit is electrically connected to the wireless charging receiving circuit, and is used to charge the battery after converting the direct current power received from the wireless charging receiving circuit. The management circuit is configured to manage the charging and discharging states of the battery; the charging control circuit is electrically connected to the charging management circuit and the wireless charging receiving circuit; the charging control circuit is configured to collect battery power information; the charging control circuit is configured to control the charging management circuit to stop charging the battery and stop sending battery power to the charging control circuit when the battery is in the charging state and detects that the battery is fully charged based on the power information of the charging management circuit; and the charging control circuit receives the DC power output by the wireless charging receiving circuit and converts the DC power to supply power to the load. In this way, the charging circuit can stop charging the battery with wireless charging power and stop supplying power to the load after detecting that the capacitive stylus battery is fully charged, and control the charging control circuit to receive wireless charging power to supply power to the load. This solves the problem of the capacitive stylus repeatedly charging after the battery power is depleted due to the load's power consumption during charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0024] Figure 1 A schematic diagram of the system structure of an embodiment of a charging circuit provided by the present utility model;

[0025] Figure 2This is a diagram showing the internal structure of a charging management circuit according to an embodiment of the charging circuit provided by the present invention;

[0026] Figure 3 This is a diagram showing the internal structure of a charging control circuit according to an embodiment of the charging circuit provided by the present invention;

[0027] Figure 4 A schematic diagram of the system structure of an embodiment of a charging circuit provided by the present utility model;

[0028] Figure 5 This is a structural diagram of an embodiment of a charging circuit provided by the utility model.

[0029] Label:

[0030] 100-charging control circuit; 110-step-down circuit; 200-wireless charging receiving circuit; 300-charging management circuit; 310-charging management chip; 320-switching circuit; 400-battery; 500-load; 600-protection circuit; 700-USB charging circuit.

[0031] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0033] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0034] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] This utility model proposes a charging circuit, which is applied to a capacitive stylus. Please refer to Figures 1 to 5 The capacitive stylus is provided with a battery 400 and a load, and the charging circuit includes:

[0036] A wireless charging receiving circuit 200 is provided with a receiving coil, is electrically connected to the charging control circuit 100, and is used to convert the magnetic flux sent by the wireless charging transmitting device into DC power;

[0037] A charging management circuit 300, electrically connected to the battery 400, and electrically connected to the wireless charging receiving circuit 200, for converting the DC power received from the wireless charging receiving circuit 200 to charge the battery 400, and for managing the charging and discharging states of the battery 400;

[0038] The charging control circuit 100 is electrically connected to the charging management circuit 300 and the wireless charging receiving circuit 200 respectively; the charging control circuit 100 is used to collect power information of the battery 400. The charging control circuit 100 is used to control the charging management circuit 300 to stop charging the battery 400 and stop sending battery 400 power to the charging control circuit 100 when the battery 400 is in a charging state and detects that the battery 400 is fully charged according to the power information of the charging management circuit 300; and receive the DC power output by the wireless charging receiving circuit 200, and convert the DC power to supply power to the load.

[0039] In this embodiment, the wireless charging receiving circuit 200 can convert the magnetic flux emitted by the wireless charging transmitting device into DC power using the QI protocol through NFC wireless charging (WLC), thereby providing DC power to the charging management circuit 300 or the charging control circuit 100. In the normal operation of the capacitive pen, the battery 400 is usually used to power the load. This is because the power supply voltages required for multiple loads in the capacitive pen are different. One or more voltage conversion circuits can be set up on the way the battery 400 sends the power to the charging control circuit 100 to power different loads, thereby meeting the normal use of multiple loads requiring different power supply voltages. During the wireless charging process of the capacitive pen, the loads that need to be run (such as the LED light indicating the charging status) are relatively small, and can be powered by the charging control circuit 100 after conversion.

[0040] In this embodiment, a plurality of voltage-dividing resistors can be set through the ADC sampling port of the charging control circuit 100 to sample the voltage of the positive terminal of the battery 400. The charging control circuit 100 sets a full-charge voltage threshold to determine whether the battery 400 is fully charged. The power information of the battery 400 can also be collected by setting a fuel gauge, and the power information is sent to the charging control circuit 100 to determine whether the battery 400 is fully charged. The charging control circuit 100 can complete the control function of the wireless charging receiving circuit 200 and the charging management circuit 300 by respectively setting a wireless communication module (such as a BLE module and a WIFI module) and a power management chip and a main controller (such as an MCU, a SOC), collect the power information of the battery 400 and the power voltage step-down function, and can also set a GR5515RGBD chip and a step-down module to complete the above functions.

[0041] Specifically, the charging control circuit 100 detects the power information of the battery 400, and the charging control circuit 100 makes a judgment based on the set full-charge voltage threshold and power information. If the power information meets the full-charge voltage threshold, the charging control circuit 100 sends a control instruction to the charging management circuit 300, controls the charging management circuit 300 to stop charging the battery 400, and controls the charging management circuit 300 to stop sending battery 400 power to the charging control circuit 100, and controls the DC power output by the wireless charging receiving circuit 200 to be sent to the charging control circuit 100. The charging control circuit 100 converts the DC power and supplies power to the load (such as an LED lamp).

[0042] In one embodiment, the charging control circuit 100 is used to control the charging management circuit 300 to send battery 400 power to the charging control circuit 100 when the battery 400 is in a charging state and detects that the battery 400 is not fully charged based on the power information of the charging management circuit 300, so as to receive the battery 400 power output by the charging management circuit 300, and convert the battery 400 power to supply power to the load.

[0043] In this embodiment, the charging control circuit 100 makes a judgment based on the set full-charge voltage threshold and the collected power information. If the power information does not meet the full-charge voltage threshold, the charging management circuit 300 is controlled to receive the DC power output by the wireless charging receiving circuit 200. The charging management circuit 300 converts the DC power to charge the battery 400. The charging control circuit 100 also controls the charging management circuit 300 to output the battery 400 power so that the converted battery 400 power is used to power the load.

[0044] In one embodiment, the charging management circuit 300 includes:

[0045] The switch circuit 320 is used to control the charging state of the battery 400 and the state of sending the power of the battery 400 to the load;

[0046] The charging management chip 310 is electrically connected to the switch circuit 320, the charging management chip 310 is electrically connected to the wireless charging receiving circuit 200, and the charging management chip 310 is electrically connected to the charging control circuit 100, and is used to control the switch circuit 320 to cut off or turn on.

[0047] In this embodiment, the switch circuit 320 is provided between the charging management chip 310 and the battery 400 circuit. The switch circuit 320 can be configured as a soft switch circuit 320. The switch circuit 320 (switching power supply resonant circuit) is implemented by forming a switch circuit 320 with a variety of components or switching tubes to manage the disconnection or conduction of the circuit between the battery 400 and the charging management chip 310. The charging management chip 310 is implemented by a CW6305BAAC linear charging chip. When the charging management chip 310 receives a control instruction sent by the charging control circuit 100, it controls the disconnection or conduction of the switch circuit 320 according to the control instruction.

[0048] In one embodiment, the charging circuit further includes:

[0049] The protection circuit 600 is electrically connected to the battery 400 and the charging management circuit 300, and is used to prevent the battery 400 from being overcharged and over-discharged.

[0050] In this embodiment, the protection circuit 600 can be implemented through the overcharge protection or over-discharge protection function of the charging management chip 310, and can also be implemented by forming an overcharge protection circuit 600 and an over-discharge protection circuit 600 by multiple MOS tubes and resistors, so as to prevent the battery 400 from being overcharged when charging and the battery 400 from being over-discharged when providing battery 400 power to the outside world.

[0051] In one embodiment, a step-down circuit is integrated in the charging control circuit 100 , and the step-down circuit is used to step down the voltage of the electric energy received by the charging control circuit 100 and then supply power to the load 500 .

[0052] In this embodiment, the step-down circuit 110 can be implemented by a linear regulator or a Buck converter, so that the charging control circuit 100 can step down the voltage of the received electric energy and then supply power to the load 500 .

[0053] In one embodiment, the charging circuit includes:

[0054] The USB charging circuit 700 is electrically connected to the charging control circuit 100 and is used to connect to a USB port. The USB charging circuit 700 is used to control the charging control circuit 100 to charge the battery 400 after receiving an external power supply input through the USB port.

[0055] In this embodiment, the USB charging circuit 700 is electrically connected to an external power source through a USB port, and the USB port includes any one or more of a Type-A interface, a Type-B interface, a Type-C interface, a miniUSB interface, and a microUSB interface, so that the capacitive pen can be connected to an external adapter through the USB port, so that the external power is converted by the adapter and sent to the charging circuit to charge the battery, so that the capacitive pen can perform wireless charging and wired charging functions.

[0056] In one embodiment, the load 500 is configured to be more than one.

[0057] In this embodiment, the load 500 includes a Hall switch, a button, an LED light, a posture sensor and an image sensor. When the capacitive pen is wirelessly charged, the Hall switch, button and image sensor are in standby mode to reduce the power consumption of the capacitive pen during wireless charging. The LED light is used to display the charging status of the capacitive pen, and the posture sensor is used to activate the Hall switch, button and image sensor.

[0058] The present invention also provides a capacitive stylus, which includes the charging circuit described above. The specific structure of the charging circuit refers to the above embodiments. Since the capacitive stylus adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0059] The present invention also provides a charging system comprising a wireless charging transmitter, a USB charger, and the capacitive stylus pen described above. The specific structure of the charging system is similar to that of the aforementioned embodiments. Since the present charging system utilizes all of the technical solutions of all of the aforementioned embodiments, it at least has all of the beneficial effects of the technical solutions of the aforementioned embodiments, which will not be detailed here. The wireless charging transmitter can be configured as a pen holder on a tablet computer, which can be connected to the tablet computer via a USB data cable to provide power to the pen holder.

[0060] The technical solution of the present utility model adopts a charging circuit, which is applied to a capacitive stylus. The capacitive stylus is provided with a battery and a load. The charging circuit includes: a wireless charging receiving circuit, in which a receiving coil is provided, and the wireless charging receiving circuit is electrically connected to the charging control circuit, and is used to convert the magnetic flux sent by the wireless charging transmitting device into direct current power; a charging management circuit, which is electrically connected to the battery and the charging management circuit is electrically connected to the wireless charging receiving circuit, and is used to charge the battery after converting the direct current power received from the wireless charging receiving circuit. The charging management circuit is used to manage the battery's charging and discharging states, as well as to collect battery power information. A charging control circuit is electrically connected to the charging management circuit and the wireless charging receiving circuit. The charging control circuit is configured to control the charging management circuit to stop charging the battery and stop sending battery power to the charging control circuit when the battery is in the charging state and, based on the battery power information from the charging management circuit, detects that the battery is fully charged. Furthermore, the charging control circuit receives the DC power output by the wireless charging receiving circuit and converts the DC power to supply power to a load. In this way, the charging circuit can detect that the capacitive stylus battery is fully charged and, upon doing so, stop charging the battery with wireless charging power and supplying power to the load, controlling the charging control circuit to receive wireless charging power to supply power to the load. This solves the problem of a capacitive stylus repeatedly charging after the battery is depleted due to power consumption by the load.

Claims

1. A charging circuit, applied to a capacitive stylus, wherein the capacitive stylus is provided with a battery and a load, characterized in that: The charging circuit comprises: A wireless charging receiving circuit, wherein a receiving coil is provided therein and the wireless charging receiving circuit is used to convert the magnetic flux transmitted by the wireless charging transmitting device into direct current power; a charging management circuit, the charging management circuit being electrically connected to the battery and the wireless charging receiving circuit, the charging management circuit being configured to convert the DC power received from the wireless charging receiving circuit to charge the battery, and the charging management circuit being configured to manage the charging and discharging states of the battery; A charging control circuit, wherein the charging control circuit is electrically connected to the charging management circuit and the wireless charging receiving circuit respectively; the charging control circuit is used to collect battery power information. The charging control circuit is used to control the charging management circuit to stop charging the battery and stop sending battery power to the charging control circuit when the battery is in a charging state and detects that the battery is fully charged according to the battery power information of the charging management circuit; and receive the DC power output by the wireless charging receiving circuit, and convert the DC power to supply power to the load.

2. The charging circuit according to claim 1, wherein: The charging control circuit is used to control the charging management circuit to send battery power to the charging control circuit when the battery is in a charging state and detects that the battery is not fully charged based on the power information of the charging management circuit, so as to receive the battery power output by the charging management circuit and convert the battery power to supply power to the load.

3. The charging circuit according to claim 1, wherein: The charging management circuit includes: a switch circuit, for controlling the charging state of the battery and the state of sending battery power to the load; A charging management chip is electrically connected to the switching circuit, the charging management chip is electrically connected to the wireless charging receiving circuit, and the charging management chip is electrically connected to the charging control circuit, and is used to control the switching circuit to be cut off or turned on.

4. The charging circuit according to claim 1, wherein: The charging control circuit is integrated with a step-down circuit, and the step-down circuit is used to step down the voltage of the electric energy received by the charging control circuit and then supply power to the load.

5. The charging circuit according to claim 1, wherein: The charging circuit comprises: A USB charging circuit is electrically connected to the charging control circuit and is used to connect to a USB port. The USB charging circuit is used to receive external power from the USB port and send it to the charging control circuit to control the charging control circuit to charge the battery.

6. The charging circuit according to claim 5, wherein: The USB charging circuit is electrically connected to an external power source through a USB port, and the USB port includes any one or more of a Type-A interface, a Type-B interface, a Type-C interface, a miniUSB interface, and a microUSB interface.

7. The charging circuit according to claim 1, wherein: The load is set to be more than one.

8. The charging circuit according to claim 7, wherein: The load includes a Hall switch, a button, an LED light, a posture sensor and an image sensor.

9. A capacitive stylus, characterized in that: The capacitive stylus comprises the charging circuit according to any one of claims 1 to 8.

10. A charging system, characterized in that: The charging system includes a wireless charging transmitter, a USB charger and the capacitive stylus as claimed in claim 9.

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