WO2020000302A1

WO2020000302A1 - Method and apparatus for collecting weak energy, and smart wearable device

Info

Publication number: WO2020000302A1
Application number: PCT/CN2018/093326
Authority: WO
Inventors: 张云翼; 华建武
Original assignee: 深圳市浩博高科技有限公司
Priority date: 2018-06-28
Filing date: 2018-06-28
Publication date: 2020-01-02

Abstract

Provided are a method and apparatus for collecting weak energy, and a smart wearable device, relating to the field of electronic technology. The method comprises: collecting weak energy in an environment that has several collection links and converting same into weak electric energy (S100); determining a collection link of current weak energy, and selecting a corresponding collection mode in a database according to the collection link, the database pre-storing a correspondence between collection links and collection modes (S200); starting the corresponding collection mode to perform weak electric energy collection, and outputting the collected weak electric energy to an energy storage unit (S300). When collecting weak energy in an environment, the weak energy in the environment is converted into weak electric energy by means of collection links, a corresponding collection mode is selected in a database for different collection links, and different collection strategies are employed for different weak energy types, thus reducing the loss of weak energy and improving collection efficiency.

Description

Method, device and intelligent wearable device for weak energy collection

Technical field

This solution belongs to the field of electronic technology, and particularly relates to a method, device and smart wearable device for weak energy collection.

Background technique

With the rapid development of smart sensor technology, the demand for smart wearable devices (including smart bracelets, smart watches, etc.) has also begun to grow explosively. Smart wearable devices generally have main functions, such as the motion detection function of smart sports bracelets, the health detection function of smart health monitoring bracelets, etc. Smart wearable devices also have some other functions, such as global positioning system, Bluetooth calling, music playback, etc. .

Currently, due to the size of smart wearable devices, the capacity of the battery of the smart wearable device is generally small, for example, the capacity of the lithium-ion battery configured in the smart bracelet or smart watch is less than 100 mA. In order to extend the battery life of smart wearable devices, weak energy in the environment, such as ambient light, human thermal energy, or kinetic energy generated in motion, can be collected to obtain electrical energy. For the collection of a variety of weak energy, because the weak energy source does not It is also the same, the characteristics of each kind of weak energy are not the same. The existing collection methods easily lead to the loss of weak energy and cannot meet the electrical energy requirements of smart wearable devices.

technical problem

In the traditional technical solution, there is a problem that the collection method easily leads to the loss of weak energy and cannot meet the power demand of the smart wearable device.

Technical solutions

This solution provides a method for weak energy harvesting, which aims to solve the problem that the existing harvesting methods in the traditional technical solution easily lead to the loss of weak energy and cannot meet the power demand of smart wearable devices.

A method for weak energy collection, the method includes:

Collect weak energy in the environment with several collection links and convert it into weak electrical energy;

Determining a current weak energy collection link, and selecting a corresponding collection mode in the database according to the collection link, the database pre-stores the correspondence between the collection link and the collection mode;

Start the corresponding collection mode for weak electrical energy collection, and output the collected weak electrical energy to the energy storage unit.

In addition, a weak energy harvesting device is provided, which is connected to the energy storage unit. The weak energy harvesting device includes:

A conversion unit for collecting weak energy in the environment through several links and converting it into weak electrical energy;

A selection unit, configured to determine the current weak energy collection link, and select a corresponding collection mode in the database according to the collection link, and the database pre-stores the correspondence between the collection link and the collection mode;

The collection unit is used to start the corresponding collection mode for weak electrical energy collection, and output the collected weak electrical energy to the energy storage unit.

In addition, a smart wearable device is also provided. The smart wearable device includes the weak energy harvesting device described above.

Beneficial effect

In this embodiment of the present invention, a database having a correspondence relationship between acquisition links and acquisition modes is established in advance. When collecting weak energy in the environment, the weak energy in the environment is converted into weak electrical energy through the acquisition link. Lu chooses the corresponding collection mode in the database, and adopts different collection strategies for different types of weak energy, which reduces the loss of weak energy and improves the collection efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a specific flowchart of a method for weak energy collection according to an embodiment of the present invention;

FIG. 2 is a specific flowchart of a light energy acquisition mode in the weak energy acquisition method provided by an embodiment of the present solution; FIG.

FIG. 3 is a specific flowchart of a thermoelectric acquisition mode in a method for weak energy acquisition provided by an embodiment of the present invention; FIG.

FIG. 4 is a specific flowchart of a kinetic energy acquisition mode in a weak energy acquisition method according to an embodiment of the present invention; FIG.

5 is a schematic structural diagram of a weak energy harvesting device according to an embodiment of the present invention;

FIG. 6 is a schematic circuit diagram of a collection unit in a weak energy collection device provided in Embodiment 1 of the present solution; FIG.

7 is a schematic circuit diagram of a collection unit in a weak energy collection device provided in Embodiment 2 of the present solution;

FIG. 8 is a circuit schematic diagram of a collection unit in a weak energy collection device provided in Embodiment 3 of the present solution; FIG.

9 is a schematic structural diagram of a kinetic energy converter according to an embodiment of the solution;

FIG. 10 is a schematic structural diagram of a kinetic energy converter according to another embodiment of the present invention.

Embodiments of the invention

In order to make the purpose, technical solution, and advantages of this solution more clear, the following further describes this solution in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the solution, and are not used to limit the solution.

FIG. 1 shows a specific flowchart of a method for weak energy collection provided by an embodiment of this solution. For convenience of explanation, only a part related to this embodiment is shown.

The method for weak energy harvesting includes the following steps:

In step S100, the weak energy in the environment is collected by several collection links and converted into weak electric energy.

As an embodiment of this solution, this method can be applied to the collection of light energy, kinetic energy, thermal energy, and wind energy, and can be collected by energy conversion units in several links, such as solar panels, pressure sensors, or kinetic energy transducers. Thermoelectric semiconductors, etc., convert the weak energy in the environment into weak electrical energy.

In step S200, the current weak energy collection link is determined, and the corresponding collection mode is selected in the database according to the collection link. The database pre-stores the correspondence between the collection link and the collection mode.

It can be understood that there are many kinds of weak energy in the environment. A single type of weak energy often cannot meet the electrical energy demand of the load. Therefore, it is necessary to collect multiple types of weak energy at the same time. However, different types of weak energy have different characteristics. For different types of weak energy, different acquisition modes need to be adopted to achieve the purpose of optimal acquisition efficiency. The above-mentioned database contains a variety of parameters with corresponding relationships, and one parameter and its corresponding relationship can be used to query the corresponding another parameter. Specifically, the serial number and the data of the acquisition mode corresponding to the serial number can be directly retrieved through the serial number.

Different acquisition links in the database correspond to different acquisition modes. By determining what type of micro-energy is the input electrical energy converted from, different acquisition modes can be used to collect the converted weak electrical energy.

As a preferred embodiment of this solution, the step of determining the weak energy type currently collected in step S200 may specifically include:

In step S201, a corresponding identifier is set on each collection link;

In step S202, an identification of the collection link that currently outputs weak electrical energy is determined, and a corresponding collection mode is selected in the database according to the identification.

It can be understood that the above-mentioned database previously stores data of the acquisition modes corresponding to a plurality of different acquisition links. The multiple acquisition links set in the embodiment of this solution are used to convert weak energy and input weak electrical energy. Among them, Each type of weak electrical energy converted into weak electrical energy corresponds to a collection link, and the multiple collection links have corresponding identifiers to form a corresponding relationship between the foregoing identifiers and weak energy collection methods. By identifying the weak input energy, The identification of the electrical energy collection link can determine the type of weak energy corresponding to the weak electrical energy. In specific applications, the collection mode in the database can be updated according to the weak energy type. Correspondingly, the collection links can be extended. These extended collection links are also set with identifiers, so that the method of this embodiment of the solution is more applicable. The collection of various types of weak energy in the environment can be updated according to the specific application environment in the database according to the collection characteristics of different types of weak energy, and the updated collection mode corresponds to the number of the collection link, which is convenient for the device. Expansion of functions.

In step S300, the corresponding collection mode is started for weak electrical energy collection, and the collected weak electrical energy is output to the energy storage unit.

As shown in Figure 2, starting the corresponding collection mode for weak electrical energy collection and outputting the collected weak electrical energy to the energy storage unit specifically includes the following steps:

In step S311, the input voltage is detected, and when the input voltage is less than the first preset value, the acquisition is turned off; when the input voltage is greater than the first preset value, the acquisition is started;

In step S312, the no-load voltage is collected, and a preset PWM signal is output according to the no-load voltage;

In step S313, the input voltage is detected periodically. When the input voltage is greater than the second preset value, the no-load voltage is read again after a predetermined time, and the output PWM signal is adjusted according to the no-load voltage. When set, the acquisition is turned off.

The no-load voltage refers to the open-circuit voltage of the input voltage, and the control data of the PWM signal in the light energy acquisition mode is retrieved and output through the no-load voltage. According to the change law of the no-load voltage, the light energy acquisition mode is combined with The measured environmental parameters are used to statistically establish a database, draw the maximum power curve that can be generated under different environmental parameters, and write the data of the maximum power curve into the database in the form of a data table. In actual use, based on the no-load voltage, Data table, predicting the maximum power curve close to the actual situation, so as to retrieve and output the control data of the collected PWM signals. During the operation, the maximum power curve is used to determine the acquisition based on the starting amount of the no-load voltage. During the acquisition process, the no-load voltage is read regularly, and the maximum power curve is corrected according to the feedback no-load voltage to reach the minimum. The maximum power is collected at its own power consumption.

In the process of micro-energy acquisition, it is necessary to reduce its own power consumption as much as possible. There is more loss in AD sampling and real-time tracking, and the use of real-time tracking and AD sampling frequency are reduced as much as possible. The input voltage is detected using digital sampling, and the no-load voltage is collected using AD sampling. The light energy sampling mode can be awakened by detecting the input voltage. Specifically, when the input voltage is high, the input voltage is greater than The first preset value indicates that there is already a weak electrical energy input converted from light energy. At this time, acquisition is started, switching to AD sampling, sampling of no-load voltage, reducing the sampling frequency of AD sampling, and reducing loss.

As shown in FIG. 3, when the light energy collection mode is started, the corresponding collection mode is started for weak electric energy collection, and the collected weak electric energy is output to the energy storage unit. The specific steps include the following steps:

In step S321, the input voltage is detected, and when the input voltage is less than the first preset value, the acquisition is turned off; when the input voltage is greater than the first preset value, the acquisition is started;

In step S322, a PWM signal is output, and the input voltage is boosted by the PWM signal;

In step S323, the voltage after the boosting process is detected, and if the voltage after the boosting process is greater than the voltage of the energy storage unit, the energy storage unit is charged; if the voltage after the boosting process is less than the voltage of the energy storage unit, the output is stopped PWM signal, turn off acquisition.

The collection of thermoelectric microenergy has the characteristics of low energy level and good stability. Because the temperature difference between body temperature and environment is generally not large, only a few degrees range, the electromotive force generated by thermoelectric semiconductor is only about ten millivolts. When collecting, you only need to wake up at regular intervals to start the collection, boost the weak electrical energy generated by thermoelectricity, boost the weak electrical energy to a usable voltage range, and generate AC power through PWM signal control. The energy storage unit is charged.

As shown in FIG. 4, when the kinetic energy collection mode is started, the corresponding collection mode is started for weak electrical energy collection, and the collected weak electrical energy is output to the energy storage unit. The specific steps include the following steps:

In step S331, the input voltage is detected, and when the input voltage is less than the first preset value, the acquisition is turned off; when the input voltage is greater than the first preset value, the acquisition is started;

In step S332, a PWM signal is output, and the input voltage is boosted by the PWM signal to charge the energy storage unit;

In step S333, after the charging is completed, the collection is turned off, and after a preset time, step S331 is performed;

The characteristic of kinetic energy is that the transientness is relatively obvious, that is, the collection of electricity generated by the strong magnet at the moment when it passes over the coil. In response to this feature, the hardware circuit is responsible for collecting as much energy as possible into the magnetic field of the transformer. Then, by controlling the output PWM signal, the weak electrical energy converted from magnetic energy is smoothly output to charge the battery.

FIG. 5 shows a schematic structural diagram of a weak energy harvesting device provided by an embodiment of the present solution. For ease of description, only a part related to this embodiment is shown.

As a preferred embodiment of this solution, the weak energy harvesting device is connected to an energy storage unit. The weak energy harvesting device includes:

A conversion unit 11 configured to collect weak energy in the environment by using several collection links and convert the weak energy into weak electrical energy;

A selection unit 12 is used to determine the current weak energy collection link, select a corresponding collection mode in the database according to the collection link, and the database pre-stores the correspondence between the collection link and the collection mode;

The collection unit 13 is configured to start a corresponding collection mode for weak electrical energy collection, and output the collected weak electrical energy to the energy storage unit.

The conversion unit includes at least one of a light energy converter, a thermoelectric converter, and a kinetic energy converter, which are respectively used to collect light energy, thermal energy, and kinetic energy generated in the environment, and convert these weak energy into weak electrical energy. For example, solar energy panels are used for light energy converters, and thermoelectric semiconductors are used for thermoelectric converters to convert the weak energy in the environment into weak electrical energy.

As shown in FIG. 9, an embodiment of this solution provides a kinetic energy converter. The kinetic energy converter includes a ring-shaped hollow tube 111, a coil 112, a ferromagnetic sphere 113, and a first circuit board 114. The ferromagnetic sphere 113 is provided in the embodiment. In the hollow circular tube 111, the coil 112 is wound around the periphery of the hollow circular tube 111. Among them, there are a plurality of coils 112, which are evenly arranged on the periphery of the annular hollow tube 111. The coil 112 is electrically connected to the first circuit board 114, and is strong. During the rolling process of the magnetic sphere 113 in the hollow circular tube 111, it passes through the coil 112, and then generates an induced electromotive force on the coil 112. The first circuit board 114 collects and converts the induced electromotive force, and converts the kinetic energy generated in the environment into Weak electrical energy.

As shown in FIG. 10, this embodiment of the present invention also provides another kinetic energy converter. The kinetic energy converter includes a second circuit board 115, a planar coil 116, a rotating arm 117, and a strong magnet 118 provided at one end of the rotating arm. The rotating arm 117 rotates with the other end of the rotating arm 117 as a central axis. The planar coil 116 is electrically connected to the second circuit board 115. There are multiple planar coils 116 and are evenly arranged on the moving path of the strong magnet 118. When the rotating arm 117 rotates, it drives the strong magnet 118 to perform an arc movement. The strong magnet passes through the planar coil 116, and then generates an induced electromotive force on the planar coil 116. The induced electromotive force is collected and converted by the second circuit board 115, and the generated electromagnetic energy is generated in the environment. The kinetic energy is converted into weak electrical energy.

The selection unit 12 further includes:

Identification module, for setting corresponding identification on each collection link;

A judging module is configured to determine an identifier of the collection link that currently outputs weak electrical energy, and select a corresponding acquisition mode in the database according to the identifier.

It can be understood that the above-mentioned database previously stores data of the acquisition modes corresponding to a plurality of different acquisition links. The multiple acquisition links set in the embodiment of this solution are used to convert weak energy and input weak electrical energy. Among them, Each type of weak energy converted into weak electrical energy is correspondingly input into a collection link, and the multiple collection links have corresponding identifiers to form a corresponding relationship between the above identifiers and weak energy collection methods. The judgment module recognizes the input by The identification of the weak electrical energy collection link can determine the type of weak energy corresponding to the weak electrical energy. In specific applications, the collection mode in the database can be updated according to the weak energy type. Correspondingly, the collection links can be extended. These extended collection links are also set with identifiers, so that the method of this embodiment of the solution is more applicable. The collection of various types of weak energy in the environment can be updated according to the specific application environment in the database according to the collection characteristics of different types of weak energy, and the updated collection mode corresponds to the number of the collection link, which is convenient for the device. Expansion of functions.

When the acquisition unit 13 selects a light energy acquisition mode, the acquisition unit 13 includes:

The input voltage detection unit is used to detect the input voltage. When the input voltage is less than the first preset value, the acquisition unit 13 is turned off; when the input voltage is greater than the first preset value, the acquisition unit 13 is started;

The acquisition unit 13 is an no-load voltage acquisition unit, configured to collect the no-load voltage and output a preset PWM signal according to the no-load voltage;

A charging module for charging the energy storage unit according to a preset PWM signal;

A timer for generating a clock signal;

The adjustment module, when the input voltage is greater than the second preset value, reads the no-load voltage again after a predetermined time, and adjusts the output PWM signal according to the no-load voltage; when the input voltage is less than the second preset value, the acquisition is turned off.

The input voltage is the voltage of the input weak electrical energy. The no-load voltage refers to the open-circuit voltage of the input voltage. The no-load voltage is used to retrieve and output the control data of the PWM signal in the light energy acquisition mode, and the light energy is collected. According to the change law of no-load voltage and the measured environmental parameters, the model statistically establishes a database, draws the maximum power curve that can be generated under different environmental parameters, and writes the data of the maximum power curve into the database in the form of a data table. When in use, according to the no-load voltage, by searching the data table, the maximum power curve close to the actual situation is predicted, so that the control data that collects the PWM signal is retrieved and output. During the operation, the maximum power curve is used to determine the acquisition based on the starting amount of the no-load voltage. During the acquisition process, the no-load voltage is read regularly, and the maximum power curve is corrected according to the feedback no-load voltage to reach the minimum. The maximum power is collected at its own power consumption.

Further, as shown in FIG. 5, the charging module includes: a first MOS tube Q1Q1, a second MOS tube Q2, a first resistor R1, a first inductor L1, and a first diode D1. The drain of the first MOS tube Q1 is connected. In the conversion unit, the source of the first MOS tube Q1 is connected to the first end of the first inductor L1, the drain of the second MOS tube Q2 is connected to the gate of the first MOS tube Q1, and the source of the second MOS tube Q2 is grounded. The drain of the two MOS transistors Q2 is connected to the conversion unit through the first resistor R1. The gate of the second MOS transistor Q2 is used to input the PWM signal. The anode of the first diode D1 is grounded, and the cathode of the first diode D1 is connected to the first A first terminal of an inductor L1 and a second terminal of the first inductor L1 are connected to the energy storage unit.

When the acquisition unit 13 selects a thermoelectric acquisition mode, the acquisition unit 13 includes:

A boosting module for outputting a PWM signal, and performing boost processing on the input voltage by using the PWM signal;

The charging module is used to detect the voltage after the boost processing. If the voltage after the boost processing is greater than the voltage of the energy storage unit, charge the energy storage unit; if the voltage after the boost processing is less than the voltage of the energy storage unit, stop outputting The PWM signal turns off the acquisition unit 13.

Further, as shown in FIG. 6, the boost module includes a third MOS tube Q3, a transformer T1, and a second diode D2. The first end of the primary coil of the transformer T1 is connected to the conversion unit, and the second end of the primary coil of the transformer T1 is connected. The drain of the third MOS tube Q3, the source of the third MOS tube Q3 is grounded, the gate of the third MOS tube Q3 is used to input the PWM signal, and the first end of the secondary coil of the transformer T1 is connected to the second diode D2. The anode and the cathode of the second diode D2 are connected to the energy storage unit.

When the acquisition unit 13 selects a kinetic energy acquisition mode, the acquisition unit 13 includes:

The charging module outputs a PWM signal. The input voltage is boosted by the PWM signal to charge the energy storage unit. After a preset time, the collection is turned off.

The characteristic of kinetic energy is that the transientness is obvious, that is, the weak electrical energy generated instantaneously needs to be collected, and then the output voltage is adjusted by controlling the output PWM signal to convert the weak electrical energy converted from magnetic energy into the form of stable voltage. Output to charge the battery.

Further, as shown in FIG. 7, the boost module includes: a rectifier circuit U1, a fourth MOS transistor Q4, a second inductor L2, and a third diode D3; an input terminal of the rectifier circuit U1 is connected to a conversion unit, and is configured to output voltage Perform rectification, the output terminal of the rectifier circuit U1 is connected to the first terminal of the second inductor L2, the drain of the fourth MOS transistor Q4 is connected to the second terminal of the second inductor L2, the source of the fourth MOS transistor Q4 is grounded, and the fourth MOS The gate of the tube Q4 is used to input the PWM signal, the second end of the second inductor L2 is connected to the anode of the third diode D3, and the cathode of the third diode D3 is connected to the energy storage unit.

The objective of this embodiment of the solution is to provide a smart wearable device, which includes the aforementioned weak energy harvesting device.

The above are only the preferred embodiments of the solution, and are not intended to limit the solution. Any modification, equivalent replacement, and improvement made within the spirit and principles of the solution shall be included in the protection of the solution. Within range.

Claims

A method for weak energy collection, characterized in that the method includes:

Collect weak energy in the environment with several collection links and convert it into weak electrical energy;

Determine the current collection link of weak energy, select a corresponding collection mode in the database according to the collection link, and the database pre-stores the correspondence between the collection link and the collection mode;

Start the corresponding collection mode for weak electrical energy collection, and output the collected weak electrical energy to the energy storage unit.
The method for weak energy collection according to claim 1, wherein the step of determining the current collection link of weak energy, and selecting a corresponding collection mode in the database according to the collection link comprises:

Set corresponding identifiers on each of the collection links;

Determine the identifier of the acquisition link that currently outputs weak electrical energy, and select a corresponding acquisition mode in the database according to the identifier.
The method for weak energy collection according to claim 1, wherein the collection mode comprises a light energy collection mode, a thermoelectric collection mode, and a kinetic energy collection mode.
The method for weak energy harvesting according to claim 3, wherein when the light energy harvesting mode is activated, the corresponding harvesting mode is activated for weak electrical energy harvesting, and the collected weak electrical energy is output to the energy storage unit It includes the following steps:

Detecting an input voltage, and turning off acquisition when the input voltage is less than a first preset value; and starting acquisition when the input voltage is greater than a first preset value that is less than a first preset value;

Collecting no-load voltage, and outputting a preset PWM signal according to the no-load voltage;

Detect the input voltage regularly, when the input voltage is greater than the second preset value, read the no-load voltage again, and adjust the PWM signal according to the no-load voltage; when the input voltage is less than the second preset value When closed, the acquisition is turned off.
The method for weak energy harvesting according to claim 3, wherein when the light energy harvesting mode is activated, the corresponding harvesting mode is activated for weak electrical energy harvesting, and the collected weak electrical energy is output to the energy storage unit It includes the following steps:

Detecting an input voltage, turning off acquisition when the input voltage is less than a first preset value, and starting acquisition when the input voltage is greater than the first preset value;

Output a PWM signal, and boost the input voltage by using the PWM signal;

Detect the voltage after the boosting process. If the voltage after the boosting process is greater than the voltage of the energy storage unit, charge the energy storage unit;

If the voltage after the boosting process is less than the voltage of the energy storage unit, the output of the PWM signal is stopped and the acquisition is turned off.
The method for weak energy harvesting according to claim 3, wherein when the kinetic energy acquisition mode is activated, the corresponding acquisition mode is activated for weak electric energy acquisition, and the collected weak electric energy is output to the energy storage unit. It includes the following steps:

Detecting an input voltage, turning off acquisition when the input voltage is less than a first preset value, and starting acquisition when the input voltage is greater than the first preset value;

Output a PWM signal, and boost the input voltage through the PWM signal to charge the energy storage unit;

After the preset time, the acquisition is turned off.
A weak energy harvesting device connected to an energy storage unit is characterized in that the weak energy harvesting device includes:

A conversion unit, configured to collect weak energy in the environment with several collection links and convert it into weak electrical energy;

A selection unit, configured to determine the current weak energy collection link, and select a corresponding collection mode in the database according to the collection link, and the database pre-stores the correspondence between the collection link and the collection mode;

The collection unit is used to start the corresponding collection mode for weak electrical energy collection, and output the collected weak electrical energy to the energy storage unit.
The weak energy harvesting device according to claim 7, wherein the selection unit comprises:

An identification module, configured to set a corresponding identification on each of the collection links;

The judging module determines an identifier of the collection link that currently outputs weak electrical energy, and selects a corresponding acquisition mode in the database according to the identifier.
The weak energy harvesting device according to claim 7, wherein the conversion unit comprises at least one of a light energy converter, a thermoelectric converter, and a kinetic energy converter.
The weak energy harvesting device according to claim 7, wherein the harvesting modes include a light energy harvesting mode, a thermoelectric harvesting mode, and a kinetic energy harvesting mode.
The weak energy harvesting device according to claim 10, wherein when the harvesting unit selects a light energy harvesting mode, the harvesting unit comprises:

An input voltage detection unit is configured to detect an input voltage, and when the input voltage is less than a first preset value, turn off the acquisition unit; when the input voltage is greater than the first preset value, start the acquisition unit;

No-load voltage acquisition unit, configured to collect no-load voltage, and output a preset PWM signal according to the no-load voltage;

A charging module for charging the energy storage unit according to a preset PWM signal;

A timer for generating a clock signal;

The adjustment module reads the no-load voltage again after a predetermined time when the input voltage is greater than a second preset value, and adjusts the output PWM signal according to the no-load voltage; when the input voltage is less than the second preset value, When set, close the acquisition unit.
The weak energy harvesting device according to claim 11, wherein the charging module comprises a first MOS tube, a second MOS tube, a first resistor, a first inductor, and a first diode; the first MOS The drain of the tube is connected to the conversion unit, the source of the first MOS tube is connected to the first end of the first inductor, and the drain of the second MOS tube is connected to the gate of the first MOS tube. The source of the second MOS tube is grounded, the drain of the second MOS tube is connected to the conversion unit through the first resistor, and the gate of the second MOS tube is used to input a PWM signal. An anode of a diode is grounded, a cathode of the first diode is connected to a first end of the first inductor, and a second end of the first inductor is connected to the energy storage unit.
The weak energy harvesting device according to claim 10, wherein when the harvesting unit selects a thermoelectric harvesting mode, the harvesting unit comprises:

An input voltage detection unit is configured to detect an input voltage, and when the input voltage is less than a first preset value, turn off the acquisition unit; when the input voltage is greater than the first preset value, start the acquisition unit;

A boosting module for outputting a PWM signal, and performing boost processing on the input voltage by using the PWM signal;

The charging module is used to detect the voltage after the boost processing. If the voltage after the boost processing is greater than the voltage of the energy storage unit, charge the energy storage unit; if the voltage after the boost processing is less than the voltage of the energy storage unit, stop outputting PWM signal to turn off the acquisition unit.
The weak energy harvesting device according to claim 13, wherein the boosting module comprises: a third MOS tube, a first transformer, and a second diode, and a first end of a primary coil of the first transformer is connected In the conversion unit, the second end of the primary winding of the first transformer is connected to the drain of the third MOS tube, the source of the third MOS tube is grounded, and the gate of the third MOS tube is used for input. For a PWM signal, the first end of the secondary winding of the first transformer is connected to the anode of the second diode, and the cathode of the second diode is connected to the energy storage unit.
The weak energy harvesting device according to claim 10, wherein when the harvesting unit selects a kinetic energy harvesting mode, the harvesting unit comprises:

An input voltage detection unit is configured to detect an input voltage, and when the input voltage is less than a first preset value, turn off the acquisition unit; when the input voltage is greater than the first preset value, start the acquisition unit;

A timer for generating a clock signal;

The boosting module outputs a PWM signal, and the input voltage is boosted by the PWM signal to charge the energy storage unit; after a preset time, the acquisition is turned off.
The weak energy harvesting device according to claim 15, wherein the boost module comprises: a rectifier circuit U1, a fourth MOS transistor Q4, a second inductor L2, and a third diode D3; and the rectifier circuit U1 The input terminal is connected to the conversion unit for rectifying the output voltage, the output terminal of the rectification circuit U1 is connected to the first terminal of the second inductor L2, and the drain of the fourth MOS transistor Q4 is connected to the The second end of the second inductor L2, the source of the fourth MOS transistor Q4 is grounded, the gate of the fourth MOS transistor Q4 is used to input a PWM signal, and the second end of the second inductor L2 is connected to the The anode of the third diode D3, and the cathode of the third diode D3 is connected to the energy storage unit.
A smart wearable device, characterized in that the smart wearable device comprises the weak energy harvesting device according to any one of claims 7 to 16.