Automatic charging circuit, automatic charging method and wearable device

Abstract

The present invention relates to the technical field of wearable devices, and provides an automatic charging circuit, an automatic charging method and a wearable device, wherein the automatic charging circuit comprises: a light energy power supply, which is used to provide a DC input voltage; a conversion circuit, which is connected to the light energy power supply, and is used to receive the DC input voltage of the light energy power supply, and generate an AC output voltage after conversion and output it to a charge pump circuit; a charge pump circuit, which receives the AC output voltage for boosting processing, and charges the boosted output voltage to a battery of an external system, so as to realize self-charging of the wearable device by using the light energy power supply and the corresponding charging circuit. The scheme can realize automatic charging of the system battery of the wearable device in a bright place indoors or outdoors, and greatly expands the use range of the wearable device.

Description

Technical Field

[0001] The present invention relates to the technical field of wearable devices, and in particular to an automatic charging circuit, an automatic charging method and a wearable device. Background Art

[0002] With the rapid development of mobile devices and wearable technology, smart glasses and smart helmets have gradually become popular products in the market. These devices usually integrate display technology, sensors, communication modules and computing power, providing users with rich interactive experience and convenient functions. However, the performance and usage experience of these smart devices are largely limited by their power solutions.

[0003] In the prior art, the power required by wearable devices comes from batteries or power converted by external adapters. This dependence limits the use time and flexibility of the device. Battery life is often the main bottleneck in the use of smart devices. Users need to charge regularly, which is not only troublesome, but may also cause the device to be unusable at critical moments. Especially in outdoor environments or environments without power outlets, especially during long outdoor activities or emergencies, the use of the device is severely restricted. Summary of the invention

[0004] The present invention provides an automatic charging circuit, an automatic charging method and a wearable device, which are used to solve the problem that the power source required by the wearable device in the prior art comes from a battery or a power source converted by an external adapter, and this dependence limits the use time and flexibility of the device. A solution for self-charging the wearable device is realized by using a light energy power source and a corresponding charging circuit. The solution can automatically charge the battery in the system in a bright place indoors or outdoors, greatly expanding the use range of the wearable device.

[0005] The present invention provides an automatic charging circuit, characterized by comprising:

[0006] A solar power source for providing a DC input voltage;

[0007] A conversion circuit, connected to the solar power source, for receiving a DC input voltage from the solar power source, converting the voltage into an AC output voltage and outputting it to a charge pump circuit;

[0008] A charge pump circuit receives the AC output voltage for boosting, and charges a battery of an external system with the boosted output voltage.

[0009] According to an automatic charging circuit provided by the present invention, a front-end protection circuit for preventing the automatic charging circuit from being short-circuited or being interfered with externally is further connected between the light energy power source and the conversion circuit;

[0010] The front-end protection circuit includes: a connector, an anti-short circuit fuse, an anti-static tube, an energy storage capacitor, an anti-reverse charging diode and an overvoltage and undervoltage protection circuit;

[0011] The connector is connected to the solar power source, and the connector, the anti-short circuit fuse, the anti-reverse charging diode and the overvoltage and undervoltage protection circuit are connected in series;

[0012] One end of the anti-static tube is connected to the anti-short circuit fuse, and the other end is grounded;

[0013] One end of the energy storage capacitor is connected to the anti-short circuit fuse, and the other end is grounded.

[0014] According to an automatic charging circuit provided by the present invention, the conversion circuit comprises:

[0015] an oscillator, the oscillator receiving the DC input voltage through an input terminal, converting the DC input voltage into an AC control signal, and outputting the AC control signal to a conversion transistor through an output terminal;

[0016] A switching transistor, wherein the gate of the switching transistor is connected to the output end of the oscillator and is used to receive the AC control signal, and the source of the switching transistor receives the DC input voltage; the drain of the switching transistor is connected to the charge pump circuit;

[0017] When the AC control signal received by the gate of the conversion transistor is at a low level, the source and drain of the conversion transistor are turned on to output the DC input voltage as a high level signal to the charge pump circuit;

[0018] When the AC control signal received by the gate of the conversion transistor is at a high level, the source and drain of the conversion transistor are cut off to output a low level signal to the charge pump circuit.

[0019] According to an automatic charging circuit provided by the present invention, the charge pump circuit comprises: a multi-stage charging circuit; each stage of the charging circuit comprises:

[0020] a primary capacitor, the primary capacitor being connected to the conversion circuit and configured to receive the AC output voltage;

[0021] A diode group, the diode group comprising a first forward-conducting diode and a second reverse-conducting diode; a common connection end of the first diode and the second diode is connected to the primary capacitor;

[0022] For the first stage charging circuit, the other end of the second diode is grounded; for the remaining stages charging circuit, the other end of the second diode is connected to the secondary capacitor of the previous stage charging circuit;

[0023] A secondary capacitor, one end of the secondary capacitor is connected to the other end of the first diode, and the other end of the secondary capacitor is connected to the ground;

[0024] For the first-stage charging circuit, energy is stored by forming an energy storage circuit through the primary capacitor, the first diode and the secondary capacitor, and a voltage is output to the next-stage charging circuit through the secondary capacitor; for the remaining-stage charging circuits, energy is stored by forming an energy storage circuit through the primary capacitor, the first diode and the secondary capacitor, and energy is stored by the output voltage of the secondary capacitor of the previous-stage charging circuit, and the boosted output voltage is output to the next-stage charging circuit through the secondary capacitor;

[0025] The first diode of the last stage charging circuit is also connected to the output end of the charge pump circuit to output the boosted output voltage to the battery of the external system for charging.

[0026] According to an automatic charging circuit provided by the present invention, the output end of the charge pump circuit is connected to the external system through a diode; the output end of the charge pump circuit is grounded through a grounding capacitor.

[0027] An automatic charging circuit provided according to the present invention also includes: a discharge circuit, which is connected to the output end of the charge pump circuit and the external system respectively, and is used to release excess electrical energy after the battery is fully charged or the external system is in a shutdown state.

[0028] According to an automatic charging circuit provided by the present invention, the discharge circuit comprises:

[0029] A discharge transistor, wherein the gate of the discharge transistor is used to receive a control signal of an external system, the drain of the discharge transistor is connected to the output end of the charge pump circuit through a resistor, and the source of the discharge transistor is grounded;

[0030] When the control signal is at a low level, the drain and source of the discharge transistor are cut off, and the automatic charging circuit charges the battery in the external system;

[0031] After the battery is fully charged or the external system is in a shutdown state, the gate of the discharge transistor receives a high-level control signal from the external system to connect the drain and source of the discharge transistor to release excess electrical energy.

[0032] The present invention also provides an automatic charging method, which is used in the automatic charging circuit as described above, and the method comprises:

[0033] The conversion circuit receives the DC input voltage of the solar power source, converts it into an AC output voltage and outputs it to the charge pump circuit;

[0034] The charge pump circuit receives the AC output voltage for boosting, and charges the boosted output voltage to a battery of an external system.

[0035] According to an automatic charging method provided by the present invention, the charge pump circuit comprises: a multi-stage charging circuit;

[0036] The method comprises: receiving the AC output voltage through the charge pump circuit to perform a voltage boost process, and outputting the boosted output voltage to a battery of an external system for charging. Specifically, the method comprises:

[0037] For the first-stage charging circuit, a storage circuit is formed by a primary capacitor, a first diode and a secondary capacitor to store energy, and an output voltage is output to the next-stage charging circuit through the secondary capacitor;

[0038] For the remaining charging circuits, an energy storage circuit is formed by the primary capacitor, the first diode and the secondary capacitor to store energy, and the secondary capacitor of the previous charging circuit releases energy to the next charging circuit for energy storage, and the boosted output voltage is transmitted to the next charging circuit through the secondary capacitor, until the last charging circuit outputs the final boosted output voltage to the battery of the external system for charging.

[0039] The present invention also provides a wearable device, comprising the automatic charging circuit as described above.

[0040] The automatic charging circuit, automatic charging method and wearable device provided by the present invention provide a DC input voltage through a solar power source, receive the DC input voltage of the solar power source through a conversion circuit, generate an AC output voltage after conversion and output it to a charge pump circuit; receive the AC output voltage through the charge pump circuit for boosting, and charge the boosted output voltage to a battery of an external system, thereby realizing self-charging of the wearable device using the solar power source and the corresponding charging circuit. This solution can realize automatic charging of the system battery of the wearable device in a bright place indoors or outdoors, greatly expanding the scope of use of the wearable device. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the present invention or 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 some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 It is a structural schematic diagram of an automatic charging circuit provided by an embodiment of the present invention.

[0043] Figure 2It is one of the schematic diagrams of the front-end protection circuit provided by the embodiment of the present invention.

[0044] Figure 3 This is the second schematic diagram of the front-end protection circuit provided by the embodiment of the present invention.

[0045] Figure 4 It is one of the schematic diagrams of the conversion circuit provided by the embodiment of the present invention.

[0046] Figure 5 This is the second schematic diagram of the conversion circuit provided by the embodiment of the present invention.

[0047] Figure 6 is a schematic diagram of a charge pump circuit provided in an embodiment of the present invention.

[0048] Figure 7 is a schematic diagram of a discharge circuit provided in an embodiment of the present invention.

[0049] Figure 8 It is a flowchart of the automatic charging method provided by an embodiment of the present invention.

[0050] Reference numerals:

[0051] 101: Photoelectric power supply; 102: Conversion circuit; 103: Charge pump circuit;

[0052] 104: external system; 105: terminal protection circuit; 106: discharge circuit. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0054] In order to realize self-charging of wearable devices by using a light power source and a corresponding charging circuit, the embodiment of the present invention uses a light power source as a voltage source for providing a DC input voltage. In this embodiment, considering the portability of the wearable device, a light power source with a small size and easy connection is selected, such as a light-powered flexible film and a flexible organic photovoltaic film OPV.

[0055] In the embodiment of the present invention, the wearable device may be a smart helmet, smart glasses or other devices.

[0056] In actual use, according to the shape of the wearable device, the light-energy flexible film or flexible organic photovoltaic film is pasted to a suitable position, such as the temples, frames and display lenses of smart glasses. The specific pasting position is not limited. Then, two contacts are reserved as the positive and negative poles of the voltage to be connected to the subsequent automatic charging circuit.

[0057] Combine the following Figure 1-Figure 7 An automatic charging circuit according to an embodiment of the present invention is described.

[0058] The embodiment of the present invention provides an automatic charging circuit. Figure 1 ,include:

[0059] A solar power source 101 is used to provide a DC input voltage;

[0060] The conversion circuit 102 is connected to the solar power source 101 and is used to receive the DC input voltage of the solar power source 101 and generate an AC output voltage after conversion to output to the charge pump circuit 103;

[0061] The charge pump circuit 103 receives the AC output voltage to perform a voltage boost process, and sends the boosted output voltage to a battery of the external system 104 for charging.

[0062] The automatic charging circuit, automatic charging method and wearable device provided by the embodiments of the present invention provide a DC input voltage through a solar power source, receive the DC input voltage of the solar power source through a conversion circuit, generate an AC output voltage after conversion and output it to a charge pump circuit; receive the AC output voltage through the charge pump circuit for boosting, and charge the boosted output voltage to the battery of an external system, thereby realizing self-charging of the wearable device using the solar power source and the corresponding charging circuit. This solution can realize automatic charging of the system battery of the wearable device in bright light indoors or outdoors, greatly expanding the scope of use of the wearable device.

[0063] The following is a detailed explanation of each component circuit in the automatic charging circuit.

[0064] Furthermore, a front-end protection circuit 105 is connected between the solar power source 101 and the conversion circuit 102 to prevent the automatic charging circuit from being short-circuited or being disturbed by external factors.

[0065] See also Figure 2 The front-end protection circuit 105 includes: a connector J1, an anti-short circuit fuse F1, an anti-static tube VR1, an energy storage capacitor C2, an anti-reverse charging diode D1 and an overvoltage and undervoltage protection circuit U1;

[0066] The connector J1 is connected to the solar power source 101, and the short-circuit protection tube F1, the reverse charging diode D1 and the overvoltage and undervoltage protection circuit U1 are connected in series with the connector J1;

[0067] One end of the anti-static tube VR1 is connected to the anti-short circuit fuse F1, and the other end is grounded;

[0068] One end of the energy storage capacitor C2 is connected to the anti-short circuit fuse F1, and the other end is grounded. The capacitance value of the energy storage capacitor C2 is greater than 10 μF.

[0069] Also, see Figure 3 , Figure 3 is a specific circuit diagram of the front-end protection circuit 105 .

[0070] The function of connector J1 is to connect the positive and negative electrodes of the light-energy flexible film, wherein pins 1 and 2 are connected to the positive electrode of the light-energy flexible film, and pins 3 and 4 are connected to the negative electrode of the light-energy flexible film.

[0071] The anti-short circuit fuse F1 is a recoverable fuse, and its function is to prevent short circuit in the circuit. When a short circuit occurs, the anti-short circuit fuse F1 will cut off the connection between the front and rear stages, and when the short circuit disappears, the conduction function will be restored.

[0072] The anti-static tube VR1 is a TVS tube, which is used to prevent static electricity from damaging subsequent circuits. When static electricity occurs, it will absorb the energy released by the static electricity and play a role in protecting the circuit.

[0073] The energy storage capacitor C2 is a large-capacity capacitor. Its function is to stabilize the voltage when there is a large fluctuation interference voltage in the system, and it also has the function of energy storage.

[0074] The anti-reverse charging diode D1 is a Schottky diode, and its function is to ensure that the electric energy flows from the positive electrode to the negative electrode, that is, the electric energy can only flow to the subsequent overvoltage and undervoltage protection circuit U1.

[0075] The overvoltage and undervoltage protection circuit U1, wherein U1 is an overvoltage and undervoltage protection chip, and the 3-pin FLAG and the 10-pin EN of the overvoltage and undervoltage protection chip U1 are connected through T1, and T1 is a PMOS tube. Specifically, the 3-pin FLAG of the overvoltage and undervoltage protection chip U1 is connected to the drain D of the PMOS tube T1, and the 10-pin EN of the overvoltage and undervoltage protection chip U1 is connected to the gate G of the PMOS tube T1.

[0076] The gate G and source S of the PMOS tube T1 are connected via a resistor R1 , and the drain D of the PMOS tube T1 is connected to the ground via a resistor R2 .

[0077] Under normal circumstances, electric energy flows from the IN pin of the overvoltage and undervoltage protection chip U1 to the OUT pin. When the voltage exceeds the specified value of the overvoltage and undervoltage protection chip U1 or is lower than the specified value of the overvoltage and undervoltage protection chip U1, the 3rd pin (FLAG) of U1 will output a low level (normally the output is a high level), and then the 1st pin (gate) of T1 will become a low level, causing the 3rd pin (drain) to become high, and then the 10th pin EN of U1 will also become a high level, thereby automatically shutting down the output of the overvoltage and undervoltage protection chip U1 when an abnormality occurs.

[0078] See also Figure 4 , the conversion circuit 102 includes:

[0079] The oscillator U2 receives a DC input voltage VIN through an input terminal, converts the DC input voltage VIN into an AC control signal VIN_EN, and outputs the AC control signal VIN_EN to the conversion transistor T3 through an output terminal OUTPUT.

[0080] The switching transistor T3 has a gate G connected to the output terminal OUTPUT of the oscillator U2 for receiving the AC control signal VIN_EN, and a source S of the switching transistor T3 receives the DC input voltage VIN; and a drain D of the switching transistor is connected to the charge pump circuit 103 .

[0081] When the AC control signal received by the gate G of the switching transistor T3 is at a low level 0, the source S and the drain D of the switching transistor T3 are turned on to output the DC input voltage VIN as a high level signal to the charge pump circuit 103 .

[0082] When the AC control signal received by the gate G of the switching transistor T3 is a high level 1, the source S and the drain D of the switching transistor T3 are cut off to output a low level signal 0 to the charge pump circuit 103, thereby outputting an AC voltage to the charge pump circuit 103.

[0083] Specifically, see Figure 5 , Figure 5 is a specific circuit diagram of the conversion circuit 102.

[0084] Among them, C52 is the filter capacitor of oscillator U2, which plays a role in stabilizing the power supply of U2.

[0085] The AC control signal output by the oscillator U2, whether it is a sine wave, a triangle wave or a square wave, can be recognized by the subsequent conversion transistor T3.

[0086] The conversion transistor T3 is a PMOS tube, and the 2nd pin (source S) of the conversion transistor T3 is connected to the power output of U1, and the 1st pin (gate G) of the conversion transistor T3 is connected to the output control signal of the oscillator. When the gate G is at a low level, the source S and the drain D of T3 are turned on, so that the power is output to the drain D. When the gate G of T3 becomes a high level, the source S and the drain D of T3 are turned off, so that the drain D of T3 is at a high level when turned on and at a low level when turned off, which is similar to the conversion from DC to AC. This is the key to realizing the boost of the subsequent charge pump circuit 103.

[0087] See also Figure 6 , the charge pump circuit 103 includes: a multi-stage charging circuit.

[0088] Each stage of the charging circuit includes: a primary capacitor connected to the conversion circuit for receiving an AC output voltage, such as the primary capacitor C3 of the first stage of the charging circuit, the primary capacitor C4 of the second stage of the charging circuit, and the primary capacitor C5 of the last stage of the charging circuit.

[0089] A diode group includes a first forward-conducting diode and a second reverse-conducting diode; a common connection end of the first diode and the second diode is connected to a primary capacitor.

[0090] For example, in the first-stage charging circuit, the diode group includes a first forward-conducting diode D3 and a second reverse-conducting diode D2, and a common connection end of the first diode D3 and the second diode D2 is connected to the primary capacitor C3.

[0091] For the first stage charging circuit, the other end of the second diode D2 is grounded, the other end of the first diode D3 is connected to the secondary capacitor C6, and the other end of the secondary capacitor C6 is grounded. The primary capacitor C3, the first diode D3 and the secondary capacitor C6 form an energy storage circuit for energy storage, and the voltage is output to the next stage charging circuit through the secondary capacitor C6.

[0092] For the remaining charging circuits, the other end of the second diode is connected to the secondary capacitor of the previous charging circuit; energy is stored by forming an energy storage circuit through the primary capacitor, the first diode and the secondary capacitor, and energy is stored through the output voltage of the secondary capacitor of the previous charging circuit, and the boosted output voltage is transmitted to the next charging circuit through the secondary capacitor.

[0093] Taking the second-stage charging circuit as an example, the diode group includes a forward-conducting first diode D5 and a reverse-conducting second diode D4, and the common connection end of the first diode D5 and the second diode D4 is connected to the primary capacitor C4. For the second-stage charging circuit, the other end of the second diode D4 is connected to the secondary capacitor C6 of the previous-stage charging circuit, and the other end of the first diode D5 is connected to the secondary capacitor C7, and the other end of the secondary capacitor C7 is grounded. The energy storage circuit formed by the primary capacitor C4, the first diode D5 and the secondary capacitor C7 stores energy, and the output voltage of the secondary capacitor C6 of the previous-stage charging circuit is used to store energy, and the boosted output voltage is transmitted to the next-stage charging circuit through the secondary capacitor C6.

[0094] For each level of charging circuit, the voltage is obtained from the 3rd pin of the previous level conversion circuit T3 (VDD in the figure), and the implementation process is from left to right.

[0095] The specific details are as follows:

[0096] First, when the VDD voltage is at a high level, the primary capacitor C3, the first diode D3 and the secondary capacitor C6 of the first-stage charging circuit form an energy storage circuit, that is, the VDD voltage is loaded into the primary capacitor C3 and the secondary capacitor C6. Due to the ESR (equivalent series resistance) in the capacitor, the primary capacitor C3 and the secondary capacitor C6 can be understood as the effect of two resistors in series, so the voltage loaded to the output end of the first diode D3 is approximately 1 / 2 of the VDD voltage. Correspondingly, the second diode D2 forms a voltage-stabilizing diode to prevent the voltage on the capacitor from being too high. When the voltage passing through the primary capacitor C3 or the secondary capacitor C6 is higher than the threshold, the voltage-stabilizing diode D2 is turned on and releases energy.

[0097] Secondly, for the second-stage charging circuit, the principle is still based on the principle that the voltage across the capacitor cannot change suddenly and that AC blocks DC, so the voltage loaded to the first diode D5 is VDD / 2. In this case, since the voltage of the secondary capacitor C6 of the first-stage charging circuit is already VDD / 2, this voltage will actually be superimposed on the voltage value of VDD / 2 through the second diode D4, and the corresponding output voltage of the first diode D5 is not VDD / 2, but VDD / 2+VDD / 2=VDD (equivalent to the standard reference ground at this time becoming the voltage of the secondary capacitor C6), which is the core point of boosting through capacitors.

[0098] Again, for the third-stage charging circuit, energy storage is repeatedly performed through the energy storage circuit formed by the primary capacitor, the first diode and the secondary capacitor, as well as the output voltage of the secondary capacitor of the previous-stage charging circuit. The output voltage of the first diode, that is, the voltage of the secondary capacitor is 3VDD / 2, and then the boosted output voltage is transmitted to the next-stage charging circuit.

[0099] The above analysis process is based on the voltage value at the moment when VDD voltage is powered on. If VDD voltage is powered off, the voltage value on the secondary capacitor will not disappear immediately, but will slowly release the energy just charged into the secondary capacitor. This requires a process. However, if VDD power is off for too long, the voltage on the secondary capacitor will slowly release. Please also note that in this case, if the VDD voltage does not change, the voltage added to the secondary capacitors C6, C7 and C8 will also slowly drop to 0V. This is due to the principle that the capacitor is DC-blocking, so the oscillator circuit of the previous stage must be added.

[0100] In addition, when performing capacitor boost, you need to pay attention to the frequency of the oscillator: if the frequency is too high, it will cause the voltage to be boosted too quickly; if the frequency is too slow, it will cause the voltage to be boosted too slowly. Therefore, the frequency of the oscillator needs to be debugged according to the actual circuit. In the actual circuit, voltage boosting requires a process. After several switching circuits, it can reach a voltage value that is stable at the multiple of VDD.

[0101] In addition, the first diode D7 of the last stage charging circuit is also connected to the output end of the charge pump circuit to output the boosted output voltage to the battery of the external system 104 for charging.

[0102] In addition to charging the battery, the boosted output voltage can also power the external system 104 to enable the external system 104 of the wearable device to operate.

[0103] In addition, the output end of the charge pump circuit 103 is connected to the pin SYSTEM_V of the external system 104 through the diode D2; the output end of the charge pump circuit 103 is grounded through the grounding capacitor C1. The function of the diode D2 is to allow the current to flow unidirectionally to the external system. The function of the grounding capacitor C1 is to store energy to prevent excessive voltage fluctuations, because the initial boost is a process, the voltage fluctuates, and the voltage value will stabilize after several boosts.

[0104] The pin SYSTEM_V of the external system 104 is further connected to the power USB_V of the external adapter through the diode D3. The function of the diode D3 is to be compatible with the power input of the external adapter, so that the system has both the power input of the light energy flexible film through the diode D2 and the adapter power input through the diode D3.

[0105] See also Figure 1 The automatic charging circuit also includes: a discharge circuit 106, which is connected to the output terminal DISCHARGE of the charge pump circuit 103 and the external system 104 respectively, and is used to release excess electrical energy after the battery is fully charged or the external system 104 is in a shutdown state.

[0106] Specifically, see Figure 7 , the discharge circuit 106 comprises:

[0107] A discharge transistor T2, wherein the gate G of the discharge transistor T2 is used to receive the control signal SYS_EN of the external system 104, the drain D of the discharge transistor T2 is connected to the output terminal DISCHARGE of the charge pump circuit 103 through the resistor R3, and the source S of the discharge transistor T2 is grounded;

[0108] When the control signal SYS_EN is at a low level 0, the drain D and the source S of the discharge transistor T2 are cut off, and the automatic charging circuit is implemented to charge the battery in the external system 104. At this time, the discharge circuit is in a non-operating state.

[0109] After the battery is fully charged or the external system 104 is in the shutdown state, when the required power is less than the power provided by the light-energy flexible film or the flexible organic photovoltaic film, the excess power needs to be released, and the gate G of the discharge transistor T2 receives the control signal SYS_EN of the external system 104. When the control signal SYS_EN is at a high level 1, the drain D and the source S of the discharge transistor T2 are turned on to release the excess power.

[0110] In addition, an embodiment of the present invention further discloses a wearable device, comprising the automatic charging circuit as described above.

[0111] The wearable device of the embodiment of the present invention can also achieve the following beneficial effects:

[0112] 1) A wearable device equipped with the automatic charging circuit can obtain power not only from its own battery or external adapter, but also from a light-energy flexible film or a flexible organic photovoltaic film self-charging system.

[0113] 2) If the built-in battery is exhausted or the adapter cannot be used for power supply, the light-powered flexible film or flexible organic photovoltaic film self-charging system can be used for power supply without causing other impacts on the wearable device.

[0114] 3) It can be used both indoors and outdoors, expanding the usage scenarios of wearable devices.

[0115] The automatic charging method provided by the present invention is described below. The automatic charging method described below and the automatic charging circuit described above can be referred to each other.

[0116] Figure 8 It is one of the flow charts of the automatic charging method provided by the present invention, such as Figure 8 As shown, the method includes the following:

[0117] Step 801: Receive a DC input voltage from a solar power source through a conversion circuit, convert it into an AC output voltage and output it to a charge pump circuit.

[0118] The conversion circuit includes: an oscillator and a conversion transistor. The specific structure of the conversion circuit is as described in the above embodiment, and will not be described in detail here.

[0119] Specifically, step 801 includes: when the AC control signal received by the gate of the conversion transistor is a low level, controlling the source and drain of the conversion transistor to be turned on to output the DC input voltage as a high level signal to the charge pump circuit; when the AC control signal received by the gate of the conversion transistor is a high level, controlling the source and drain of the conversion transistor to be turned off to output the low level signal to the charge pump circuit.

[0120] Step 802: Receive the AC output voltage through the charge pump circuit to perform voltage boosting, and charge the boosted output voltage to a battery of an external system.

[0121] Step 802 includes:

[0122] For the first-stage charging circuit, a storage circuit is formed by a primary capacitor, a first diode and a secondary capacitor to store energy, and an output voltage is output to the next-stage charging circuit through the secondary capacitor;

[0123] For the remaining charging circuits, an energy storage circuit is formed by the primary capacitor, the first diode and the secondary capacitor to store energy, and the secondary capacitor of the previous charging circuit releases energy to the next charging circuit for energy storage, and the boosted output voltage is transmitted to the next charging circuit through the secondary capacitor, until the last charging circuit outputs the final boosted output voltage to the battery of the external system for charging.

[0124] Specifically, for the specific structure and working principle of the charge pump circuit, refer to the detailed description of the aforementioned embodiment.

[0125] In addition, for the working principle and working process of the front-end protection circuit and the discharge circuit, please refer to the aforementioned embodiment, and this embodiment will not be repeated.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An automatic charging circuit, characterized in that: include: A solar power source for providing a DC input voltage; A conversion circuit, connected to the solar power source, for receiving a DC input voltage from the solar power source, converting the voltage into an AC output voltage and outputting it to a charge pump circuit; A charge pump circuit, wherein the charge pump circuit receives the AC output voltage, performs voltage boosting processing, and charges a battery of an external system after the voltage boosting; Wherein, the conversion circuit comprises: an oscillator, the oscillator receiving the DC input voltage through an input terminal, converting the DC input voltage into an AC control signal, and outputting the AC control signal to a conversion transistor through an output terminal; A switching transistor, wherein the gate of the switching transistor is connected to the output end of the oscillator and is used to receive the AC control signal, and the source of the switching transistor receives the DC input voltage; the drain of the switching transistor is connected to the charge pump circuit; When the AC control signal received by the gate of the conversion transistor is at a low level, the source and drain of the conversion transistor are turned on to output the DC input voltage as a high level signal to the charge pump circuit; When the AC control signal received by the gate of the conversion transistor is at a high level, the source and drain of the conversion transistor are cut off to output a low level signal to the charge pump circuit; The charge pump circuit comprises: a multi-stage charging circuit; Each level of the charging circuit comprises: A primary capacitor, the primary capacitor is connected to the conversion circuit and is used to receive the AC output voltage; A diode group, the diode group comprising a first forward-conducting diode and a second reverse-conducting diode; a common connection end of the first diode and the second diode is connected to the primary capacitor; For the first stage charging circuit, the other end of the second diode is grounded; for the remaining stages charging circuit, the other end of the second diode is connected to the secondary capacitor of the previous stage charging circuit; A secondary capacitor, one end of the secondary capacitor is connected to the other end of the first diode, and the other end of the secondary capacitor is connected to the ground; For the first-stage charging circuit, energy is stored by forming an energy storage circuit through the primary capacitor, the first diode and the secondary capacitor, and a voltage is output to the next-stage charging circuit through the secondary capacitor; for the remaining-stage charging circuits, energy is stored by forming an energy storage circuit through the primary capacitor, the first diode and the secondary capacitor, and energy is stored by the output voltage of the secondary capacitor of the previous-stage charging circuit, and the boosted output voltage is output to the next-stage charging circuit through the secondary capacitor; The first diode of the last stage charging circuit is also connected to the output end of the charge pump circuit to output the boosted output voltage to the battery of the external system for charging.

2. The automatic charging circuit according to claim 1, characterized in that: A front-end protection circuit is also connected between the light energy power source and the conversion circuit to prevent the automatic charging circuit from short-circuiting or being disturbed by external factors; The front-end protection circuit includes: a connector, an anti-short circuit fuse, an anti-static tube, an energy storage capacitor, an anti-reverse charging diode and an overvoltage and undervoltage protection circuit; The connector is connected to the solar power source, and the connector, the anti-short circuit fuse, the anti-reverse charging diode and the overvoltage and undervoltage protection circuit are connected in series; One end of the anti-static tube is connected to the anti-short circuit fuse, and the other end is grounded; One end of the energy storage capacitor is connected to the anti-short circuit fuse, and the other end is grounded.

3. The automatic charging circuit according to claim 1, characterized in that: The output end of the charge pump circuit is connected to the external system through a diode; The output end of the charge pump circuit is grounded via a grounding capacitor.

4. The automatic charging circuit according to claim 1, characterized in that: Also includes: A discharge circuit is connected to the output end of the charge pump circuit and the external system respectively, and is used to release excess electrical energy after the battery is fully charged or the external system is in a shutdown state.

5. The automatic charging circuit according to claim 4, characterized in that: The discharge circuit comprises: A discharge transistor, wherein the gate of the discharge transistor is used to receive a control signal of an external system, the drain of the discharge transistor is connected to the output end of the charge pump circuit through a resistor, and the source of the discharge transistor is grounded; When the control signal is at a low level, the drain and source of the discharge transistor are cut off, and the automatic charging circuit charges the battery in the external system; After the battery is fully charged or the external system is in a shutdown state, the gate of the discharge transistor receives a high-level control signal from the external system to connect the drain and source of the discharge transistor to release excess electrical energy.

6. An automatic charging method, characterized in that: For the automatic charging circuit according to any one of claims 1 to 5, the method comprises: The conversion circuit receives the DC input voltage of the solar power source, converts it into an AC output voltage and outputs it to the charge pump circuit; The charge pump circuit receives the AC output voltage for boosting, and charges the battery of the external system with the boosted output voltage; The charge pump circuit comprises: a multi-stage charging circuit; The method comprises: receiving the AC output voltage through the charge pump circuit to perform a voltage boost process, and outputting the boosted output voltage to a battery of an external system for charging. Specifically, the method comprises: For the first-stage charging circuit, a storage circuit is formed by a primary capacitor, a first diode and a secondary capacitor to store energy, and an output voltage is output to the next-stage charging circuit through the secondary capacitor; For the remaining charging circuits, an energy storage circuit is formed by the primary capacitor, the first diode and the secondary capacitor to store energy, and the secondary capacitor of the previous charging circuit releases energy to the next charging circuit for energy storage, and the boosted output voltage is transmitted to the next charging circuit through the secondary capacitor, until the last charging circuit outputs the final boosted output voltage to the battery of the external system for charging.

7. A wearable device, characterized in that: The invention comprises an automatic charging circuit as claimed in any one of claims 1 to 5.

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