WO2022152005A1

WO2022152005A1 - Battery protection circuit and hair dryer

Info

Publication number: WO2022152005A1
Application number: PCT/CN2021/144042
Authority: WO
Inventors: 雷云; 张智锋; 欧阳明星
Original assignee: 深圳市华思旭科技有限公司
Priority date: 2021-01-13
Filing date: 2021-12-31
Publication date: 2022-07-21
Also published as: CN219396533U

Abstract

Provided is a battery protection circuit. The battery protection circuit is connected to a battery module composed of a plurality of batteries that are connected in series. The battery protection circuit comprises a measurement module, a controller module, and a heat generation module, which are successively electrically connected, wherein the measurement module measures, in real time, a parameter of each battery in the battery module, and transmits the measured parameters to the controller module; the controller module compares the measured parameter of each battery with a preset first threshold, and when it is determined that the measured parameter of the battery is less than the first threshold, the controller module triggers the generation of a heat generation control signal and sends the heat generation control signal to the heat generation module; and the heat generation module cuts off a power supply path between the battery module and the heat generation module according to the heat generation control signal, such that a hair dryer is switched from a first working mode to a second working mode, the power of the first working mode being greater than the power of the second working mode. The present application further relates to a hair dryer comprising the battery protection circuit.

Description

Battery protection circuit and hair dryer

technical field

The present application relates to the technical field of hair dryers, and in particular, to a battery protection circuit and a hair dryer having the battery protection circuit.

Background technique

As a common household appliance, a hair dryer is mostly used in daily households to blow hair after washing hair, so it is often placed or used in the bathroom. When in use, the hair dryer needs to be plugged into the mains socket to obtain power through the power cord. Due to the limitation of the location of the mains socket and the length of the power cord, not only the flexibility of use is also poor, but the usage scenarios are also very limited. Therefore, wireless hair dryers with rechargeable batteries are more and more popular among consumers, and gradually become the development trend of the market.

However, if the battery in the wireless hair dryer is low in power, if it continues to discharge with high power, it may damage the cells inside the battery, and even cause a micro-short circuit inside the cell, and a serious micro-short circuit may lead to rechargeable batteries. Fire or explosion. At this time, if the wireless hair dryer continues to work in a high-power mode, the internal rechargeable battery will have certain safety hazards during use. Therefore, how to detect the battery in real time and switch the working mode when the battery is insufficient to avoid the safety problem during use has become an urgent problem for technicians to solve.

SUMMARY OF THE INVENTION

In view of the above-mentioned deficiencies of the prior art, the purpose of the present application is to provide a battery protection circuit and a hair dryer with the battery protection circuit, which aims to solve the problem that the wireless hair dryer existing in the prior art is in use due to insufficient power and continues to Battery damage and use safety issues caused by using hot air mode.

A battery protection circuit is electrically connected to a battery module composed of a plurality of batteries, the battery protection circuit includes a detection module, a controller module and a heating module, and the detection module detects each battery module in the battery module. parameters of the battery, the controller module generates a heating control signal when the detected parameter of the battery is less than the first threshold, and the heating module makes the device where the heating module is located according to the heating control signal Switch from the first working mode to the second working mode.

The battery protection circuit provided by the present application is electrically connected to a battery module composed of a plurality of batteries, and the battery protection circuit includes the detection module, the controller module and the heating module that are electrically connected in sequence. The battery protection circuit of the present application detects the battery parameters of the battery module during operation in real time, and when it is detected that the parameters of any battery are less than the preset first threshold, the hair dryer automatically operates in a high-power working mode. Switch to the low-power working mode to avoid damage to the battery in the hair dryer when the hair dryer is still working in the high-power working mode when the battery power of the battery module is insufficient, which may cause the hair dryer to generate electricity during use. safety issues, thereby avoiding unnecessary harm to users.

Optionally, the detection module is electrically connected to the battery module and the controller module, respectively, and the heating module is electrically connected to the controller module and the battery module, respectively; the detection module Detect the parameters of each battery in the battery module in real time, and transmit the parameters of the battery to the controller module; the controller module compares the parameters of the battery with a preset first threshold , when it is judged that the detected parameter of the battery is less than the first threshold, a heating control signal is triggered to generate, and the heating control signal is sent to the heating module; the heating module makes the heating control signal according to the heating control signal. The wireless hair dryer is switched from the first working mode to the second working mode.

Optionally, the battery protection circuit further includes a motor, and the motor and the heating module adjust the working conditions according to the heating control signal, so that the device where the heating module is located is switched from the first working mode to the second working mode, Or, the controller module generates a motor control signal when the detected parameter of the battery is less than the first threshold; the heating module makes the device where the heating module is located by the first control signal according to the motor control signal The working mode is switched to the second working mode.

Optionally, the detection module is respectively connected to the battery module and the controller module, and the detection module transmits the parameters of the battery to the controller module; and/or the heating module is respectively Connected with the controller module and the battery module, the controller module sends the heating control signal to the heating module.

Optionally, the device where the heating module is located includes a hair dryer.

Optionally, the plurality of batteries in the battery module are arranged in series.

Optionally, the heating module disconnects the power supply path between the battery module and the heating module according to the heating control signal, so that the hair dryer is switched from the first working mode to the second working mode. model.

Optionally, the power of the first working mode is greater than the power of the second working mode.

Optionally, the detection module is also used to realize the connection or disconnection between the battery module and the controller module. When the blower stops working, the battery module passes through the detection module. A circuit break from the controller module is achieved.

Optionally, the detection module is a voltage detection module, and the parameter is the voltage of the battery.

Optionally, the detection module includes a first resistor, a third resistor, a first triode, a third diode and a first field effect transistor, wherein one end of the first resistor receives a first power supply voltage, The other end of the first resistor is electrically connected to the first end of the first triode through a first diode and a second diode arranged in series and reversely, and the first end of the first triode is electrically connected. The two ends are grounded, the control end of the first transistor is electrically connected to one end of the third resistor; the third diode is connected between the source and the drain of the first field effect transistor , the source of the first field effect transistor receives the battery voltage, the voltage of the drain of the first field effect transistor is the second power supply voltage, and one end of the third resistor receives a high-level drive signal, so that all The first field effect transistor is turned on, and the second power supply voltage is equal to the battery voltage.

Optionally, the battery protection circuit further includes a voltage divider circuit module, the voltage divider circuit module is electrically connected to the detection module and the controller module respectively, and the voltage divider circuit module is used for receiving the detection The voltage detected by the module is subjected to voltage division processing to generate a detection voltage, and the detection voltage is transmitted to the controller module.

Optionally, the voltage dividing circuit module includes a tenth resistor, an eleventh resistor, a twelfth resistor and a third capacitor, and the tenth resistor and the eleventh resistor are connected in series with the second power supply voltage Between the input terminal of the twelfth resistor and the ground terminal, one end of the twelfth resistor is electrically connected between the tenth resistor and the eleventh resistor, and one end of the third capacitor is electrically connected to the first resistor Between the eleventh resistor and the ground terminal, the other end of the third capacitor is electrically connected to the other end of the twelfth resistor.

Optionally, the heating module includes a switch unit and a heating unit, the switch unit is used to control the power supply of the battery module to the heating unit based on the heating control signal, and the heating unit is used to control the power supply of the heating unit based on the heating control signal. The electrical energy provided by the battery module is converted into thermal energy.

Optionally, when the heating control signal is at a first level, the switch unit stops working at the first level, and the battery module stops or limits power supply to the heating unit, so that the heating unit is heated. The device where the module is located enters the second working mode; when the heating control signal is at the second level, the switch unit keeps working at the second level, and the battery module keeps the heating unit Power is supplied, so that the device where the heating module is located maintains the first working mode. The first level may be a high level and the second level may be a low level, or the first level may be a low level and the second level may be a high level.

Optionally, the heating control signal is a pulse signal, and the controller adjusts the duty cycle of the pulse signal, and the pulse signal controls the turn-on duty cycle of the second field effect transistor, so that the heating is performed. The device where the module is located enters the second working mode.

Optionally, exemplarily, the switch unit includes a field effect transistor, and the power supply condition is controlled by turning the field effect transistor on and off.

Optionally, the switch unit may include a seventeenth resistor, an eighteenth resistor, a sixth diode and a second field effect transistor, and the heating unit may include a heating wire, a high-power resistance wire, an infrared heater, and the like.

Optionally, the other end of the seventeenth resistor is electrically connected to the gate of the second field effect transistor, one end of the eighteenth resistor is connected to the ground terminal, and the other end of the eighteenth resistor is connected to the ground. is electrically connected to the gate of the second field effect transistor, the source of the second field effect transistor is connected to the ground terminal, and the eighteenth resistor is electrically connected to the second field effect transistor Between the gate and the source, the source of the second field effect transistor is electrically connected to the anode of the sixth diode, and the drain of the second field effect transistor is connected to the sixth diode Between the negative electrode of the tube and one end of the heating unit, the other end of the heating unit receives the battery voltage.

Optionally, the heating control signal input from one end of the seventeenth resistor is at a high level, the second field effect transistor is turned on, and the battery voltage supplies power to the heating module, so that the hair dryer is in the first working mode; or, the heating control signal input to one end of the seventeenth resistor is at a low level, the second field effect transistor is disconnected, and the battery voltage stops supplying power to the heating module , the heating module stops working, so that the hair dryer enters the second working mode.

Optionally, the heating control signal input from one end of the seventeenth resistor is a pulse signal, and the pulse signal controls the conduction duty ratio of the second field effect transistor, so that the blower enters the second field effect tube. Operating mode.

Optionally, the first working mode includes a first gear, a second gear and a third gear, and the voltage corresponding to the first gear is the first gear voltage, which is the same as the second gear. The corresponding voltage is the second gear voltage, and the voltage corresponding to the third gear is the third gear voltage; when the controller module determines that the voltage of the battery module is greater than the first gear voltage, the hair dryer works in the first gear; when the controller module determines that the voltage of the battery module is lower than the first gear voltage and higher than the second gear voltage , the hair dryer is automatically switched from the first gear to the second gear; when the controller module determines that the voltage of the battery module is lower than the voltage of the second gear and higher than the voltage of the second gear When the voltage of the third gear is used, the hair dryer is automatically switched from the second gear to the third gear; when the controller module determines that the voltage of the battery module is lower than the third gear voltage, the hair dryer is automatically switched from the third gear to the second working mode, wherein the third gear voltage is equal to the first threshold.

Optionally, the sixth diode is a Zener diode, and the first threshold is between 3.0V-3.3V.

Optionally, the first working mode is a hot air mode, and the second working mode is a cold air mode.

The present application also relates to a hair dryer, comprising the above-mentioned battery protection circuit and a battery module, the battery protection circuit is electrically connected to a battery module composed of a plurality of batteries, and the battery protection circuit includes a detection module and a controller module and a heating module; the detection module detects the parameter of each battery in the battery module; the controller module generates a heating control signal when the detected parameter of the battery is less than the first threshold; the The heating module switches the device where the heating module is located from the first working mode to the second working mode according to the heating control signal.

The purpose of this application is to provide a hair dryer that can safely protect the battery of the wireless hair dryer while ensuring its use function, avoid the phenomenon of micro-short circuit in the internal circuit of the wireless hair dryer caused by battery overcharge or overdischarge, and also avoid the wireless hair dryer. The generation of safety hazards caused by aging or failure.

Optionally, the heating module disconnects the power supply path between the battery module and the heating module according to the heating control signal, so that the hair dryer is switched from the first working mode to the second working mode. mode, wherein the power of the first working mode is greater than the power of the second working mode.

Optionally, the first working mode includes a first gear, a second gear and a third gear, and the voltage corresponding to the first gear is the first gear voltage, which is the same as the second gear. The corresponding voltage is the second gear voltage, and the voltage corresponding to the third gear is the third gear voltage.

Optionally, when the controller module determines that the voltage of the battery module is greater than the voltage of the first gear, the blower works in the first gear; when the controller module determines that the voltage of the first gear is When the voltage of the battery module is lower than the voltage of the first gear and higher than the voltage of the second gear, the hair dryer is automatically switched from the first gear to the second gear; when the When the controller module determines that the voltage of the battery module is lower than the voltage of the second gear and higher than the voltage of the third gear, the hair dryer is automatically switched from the second gear to the third gear gear; when the controller module determines that the voltage of the battery module is lower than the voltage of the third gear, the hair dryer is automatically switched from the third gear to the second working mode, wherein , the third gear voltage is equal to the first threshold.

Optionally, the hair dryer further includes a main control board and a display module, the main control board is electrically connected to the battery module, the battery protection circuit and the display module, respectively, and the display module is used for displaying The power and charging status of the hair dryer.

Optionally, the main control board performs real-time detection on the charging voltage of the battery module, and when detecting that the charging voltage of any battery in the battery module is greater than a preset second threshold, the battery The module stops charging; or, the main control board performs real-time detection on the charging voltage of the battery module, and when detecting that the charging voltage of any battery in the battery module is less than a preset third threshold, The battery module stops discharging.

Optionally, the second threshold is between 4.1V-4.25V, and the third threshold is between 2.5V-3.0V.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the accompanying drawings that need to be used in the embodiments. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a circuit block diagram of a hair dryer disclosed in an embodiment of the application;

FIG. 2 is a schematic diagram of the circuit structure of the detection module of the battery protection circuit shown in FIG. 1;

FIG. 3 is a schematic diagram of the circuit structure of the voltage divider circuit module of the battery protection circuit shown in FIG. 1;

FIG. 4 is a schematic diagram of the circuit structure of the controller module of the battery protection circuit shown in FIG. 1;

FIG. 5 is a schematic diagram of the circuit structure of the heating module of the battery protection circuit shown in FIG. 1;

FIG. 6 is a circuit block diagram of another hair dryer disclosed in an embodiment of the present application.

Detailed ways

In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the related drawings. The preferred embodiments of the present application are shown in the accompanying drawings. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that a thorough and complete understanding of the disclosure of this application is provided.

The following descriptions of the various embodiments refer to the accompanying drawings to illustrate specific embodiments in which the present application may be practiced. The serial numbers themselves, such as "first", "second", etc., for the components herein are only used to distinguish the described objects, and do not have any order or technical meaning. The "connection" and "connection" mentioned in this application, unless otherwise specified, include both direct and indirect connections (connections). Directional terms mentioned in this application, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "side", etc., only Reference is made to the directions of the accompanying drawings, therefore, the directional terms used are for better and clearer description and understanding of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, in a specific orientation construction and operation, and therefore should not be construed as limitations on this application.

In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection Ground connection, or integral connection; mechanical connection; direct connection, indirect connection through an intermediate medium, or internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood in specific situations. It should be noted that the terms "first", "second", "third", etc. in the description and claims of the present application and the drawings are used to distinguish different objects, rather than to describe a specific order. . Furthermore, the terms "comprising", "may include", "including", or "may comprise" as used in this application indicate the presence of the corresponding features, numbers, operations, elements, components, or combinations thereof disclosed in the specification, without limitation The presence or addition of one or more other features, numbers, operations, elements, components, or combinations thereof, is intended to cover a non-exclusive inclusion.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the present application are for the purpose of describing particular embodiments only, and are not intended to limit the present application.

The present application hopes to provide a solution that can solve the above technical problems, so that the use of the wireless hair dryer can be more convenient and comfortable, while ensuring the user's sense of experience, it is also necessary to ensure the safety of the use of the wireless hair dryer. The details thereof will be described in subsequent embodiments.

Please refer to FIG. 1 , which is a circuit block of a hair dryer disclosed in an embodiment of the present application. As shown in FIG. 1 , the hair dryer provided by the present application includes a battery module 10 and a battery protection circuit 20 . The battery module 10 includes a plurality of batteries, and the battery module 10 composed of the plurality of batteries is used to provide working power for the hair dryer. so that the hair dryer can work properly. The battery protection circuit 20 is electrically connected to the battery module 10 for real-time detection of parameters of each battery in the battery module 10 . When the hair dryer is working (that is, when the hair dryer is in the working state or in use state), for example, when the hair dryer is in the first working mode, the battery protection circuit 20 detects that the parameter of any battery is smaller than the preset first When the threshold value is reached, when the power of the battery module 10 is insufficient, the hair dryer automatically switches to the second working mode. The device where the heating module is located may not only include a wireless hair dryer, but also a wired hair dryer, and may also include heating devices such as a dryer, a foot blower, and a bathroom heater. In this embodiment, a hair dryer is used as an example, but it is not limited to be implemented only in a hair dryer.

In an embodiment of the present application, the first working mode may be a hot air mode, the second working mode may be a cold air mode, and the power of the first working mode is greater than the power of the second working mode. Or, the first working mode may be a hot air mode, the second working mode may be a shutdown mode, and the power of the second working mode is zero. In the embodiments of the present application, the batteries include lithium batteries or other types of batteries, and the battery module 10 is a battery pack composed of a plurality of lithium batteries. The cordless hair dryer is not limited to include only the battery module as an energy supply module, but may also include capacitors or others.

Therefore, the battery protection circuit 20 of the present application performs real-time detection on the parameters of the battery of the battery module 10 during operation, and when it is detected that the parameter of any battery is less than the preset first threshold, the wireless hair dryer is controlled by The high-power working mode is automatically switched to the low-power working mode, so as to prevent the battery in the wireless hair dryer from being drained when the wireless hair dryer still works in the high-power working mode when the battery power of the battery module 10 is insufficient. Damage to the wireless hair dryer may cause safety problems during use, thereby avoiding unnecessary harm to the user.

In an embodiment of the present application, it further includes a motor, and the motor and the heating module adjust the working conditions according to the heating control signal, so that the device where the heating module is located is switched from the first working mode to the second working mode . Or, the controller module generates a motor control signal when the detected parameter of the battery is less than the first threshold, and the heating module causes the device where the heating module is located to be controlled by the first motor according to the motor control signal. The working mode is switched to the second working mode.

Specifically, referring to FIG. 1 , in this embodiment, the battery protection circuit 20 at least includes a detection module 100 , a voltage divider circuit module 200 , a controller module 300 , and a heating module 400 . The detection module 100 is electrically connected to the battery module 10 and the voltage divider circuit module 200 respectively, and the controller module 300 is electrically connected to the voltage divider circuit module 200 and the heating module 400, respectively. The battery module 10 is also electrically connected to the heating module 400 . The detection module 100 is used to detect the parameters of each battery in the battery module 10 in real time, and transmit the detected parameters to the voltage divider circuit module 200, and the voltage divider circuit module 200 performs the received parameters. voltage division processing to generate a detection voltage, and transmit the detection voltage to the controller module 300, the controller module 300 compares the detection voltage with a preset first threshold, and when it is determined that the When the detected voltage is less than the first threshold, a heating control signal is triggered to generate, and the heating control signal is sent to the heating module 400, and the heating module 400 disconnects the battery module 10 from the heating control signal according to the heating control signal. The power supply path between the heating modules 400 enables the battery module 10 to stop supplying power to the heating modules 400 . At this time, the wireless hair dryer is automatically switched from a high-power working mode (eg, hot air mode) to a low-power working mode (eg, cold air mode).

In this embodiment of the present application, when the controller module 300 detects that the detection voltage is greater than or equal to the first threshold, the battery module 10 can continue to supply power to the heating module 400, and at this time the wireless hair dryer Continue the current working mode. It can be understood that the detection voltage is obtained by dividing the voltage of the battery in the battery module 10 by the voltage dividing circuit module 200. Therefore, the detection voltage also directly reflects the use process of the wireless hair dryer. The parameters of each battery in the battery module 10 are described in . In one embodiment, a plurality of batteries in the battery module 10 are arranged in series; wherein, the above parameter is the voltage of the batteries.

Therefore, the hair dryer of the present application mainly transmits the real-time detected parameters of each battery to the voltage divider circuit module 200 through the detection module 100, and the voltage divider circuit module 200 performs voltage division processing on the received parameters to generate corresponding Detecting the voltage and transmitting it to the controller module 300, the controller module 300 compares the detected voltage with a first threshold, and triggers generation when it is determined that the detected voltage is less than the first threshold parameter corresponding heating control signal, the controller module 300 sends the generated heating control signal to the heating module 400, and the heating module 400 disconnects the power supply path with the battery module 10 according to the heating control signal, So that the battery module 10 stops supplying power to the heating module 400, and the hair dryer is in a low-power working mode, such as a cold air mode. Therefore, the battery protection circuit 20 of the present application can detect the parameters of any battery in the battery module 10 in real time. When the detected voltage of any battery is less than the first threshold, it means that the battery can no longer carry the power of the battery. The hair dryer continues to output hot air, and if the high-power discharge continues, it may cause damage to the cells inside the battery. When the hair dryer cannot continue to provide hot air, the hair dryer enters the cold air mode and prompts the user that the battery module 10 needs to be charged, so as to automatically switch the working mode of the wireless hair dryer to the battery module. 10 protection.

In the embodiments of the present application, the detailed content of each functional circuit in the battery protection circuit 20 will be specifically described and described in subsequent embodiments below.

In one embodiment, the detection module 100 is further configured to realize the connection or disconnection between the battery module 10 and the controller module 300 . Specifically, when the wireless hair dryer stops working, the battery module 10 disconnects the circuit between the battery module 10 and the controller module 300 through the detection module 100, that is, when the wireless hair dryer does not work, The controller module 300 is powered off internally, so as to reduce the internal power consumption of the wireless hair dryer, and the electrical connection between the battery module 10 and the controller module 300 can be restored by operating buttons or charging. It can be understood that the electrical connection between the battery module 10 and the controller module 300 is realized by the detection module 100 . In one embodiment, the detection module 100 is a voltage detection module.

For an embodiment, please refer to FIG. 2. FIG. 2 is a schematic diagram of a circuit structure of a detection module 100. The detection module 100 at least includes first to ninth resistors R1-R9, a first capacitor C1 and a second capacitor C2, a first The transistor Q1 and the second transistor Q2, the first field effect transistor Q3, the first diode D1, the second diode D2, the third diode D3 and the fourth diode D4, and the integrated circuit U1. One end of the first resistor R1 receives the first power supply voltage VDD, and the other end of the first resistor R1 is electrically connected to the anode of the first diode D1. The negative electrode of the first diode D1 is connected in series with the negative electrode of the second diode D2, that is, the first diode D1 and the second diode D2 are arranged in series and reversed. The circuit in the module 100 plays the role of overvoltage protection, that is, when the circuit is overvoltage, the first diode D1 will firstly break down and short circuit, so as to form protection for the second diode D2.

The first end of the first triode Q1 is electrically connected to the anode of the second diode D2, the second end of the first triode Q1 is grounded, and the first end of the first triode Q1 is grounded. The control terminal is electrically connected to one end of the third resistor R3, the other terminal of the third resistor R3 receives the driving signal PWR_ON, and the second resistor R2 is electrically connected to the control terminal of the first transistor Q1 and the between the second ends. The first end of the second transistor Q2 is electrically connected to one end of the sixth resistor R6, and the second end of the second transistor Q2 is electrically connected to the second end of the first transistor Q1 Connected and grounded, the control terminal of the second transistor Q2 receives a charging voltage VCH through the fifth resistor R5, and the fourth resistor R4 is electrically connected to the control terminal of the second transistor Q2 and the between the second ends. The other end of the resistor R6 is electrically connected to one end of the resistor R7, and the other end of the resistor R7 is electrically connected to the source of the first field effect transistor Q3. That is, the resistor R7 is electrically connected between the source and the gate of the first field effect transistor Q3, and the gate of the first field effect transistor Q3 is electrically connected to the resistor R6 and the resistor between R7. In addition, the source of the first field effect transistor Q3 receives the battery voltage BAT+.

It can be seen from the schematic diagram of FIG. 2 that the first field effect transistor Q3 and the third diode D3 are connected in parallel in the circuit. Specifically, the third diode D3 is connected to the first field effect transistor. between the source and the drain of the transistor Q3, wherein the source of the first field effect transistor Q3 is electrically connected to the negative electrode of the third diode D3, and the drain of the first field effect transistor Q3 is electrically connected to the The anode of the third diode D3 is electrically connected. It can be understood that when an inductive load is connected to the source and drain of the third diode D3, the inductance current of the first field effect transistor Q3 cannot change abruptly when it is turned off. The freewheeling of the third diode D3 can prevent the high voltage generated in the circuit from breaking down the first field effect transistor Q3, that is, the third diode D3 is designed in parallel with the first field effect transistor Q3 The first field effect transistor Q3 can be protected, and the damage of the first field effect transistor Q3 caused by the high voltage generated in the circuit can be avoided.

In this embodiment, the first field effect transistor Q3 may be a P-channel field effect transistor.

The eighth resistor R8 and the ninth resistor R9 are connected in parallel, wherein one end of the eighth resistor R8 and the ninth resistor R9 connected in parallel is electrically connected to the drain of the first field effect transistor Q3. The other end of the resistor R8 and the ninth resistor R9 in parallel are both electrically connected to the input end of the integrated circuit U1 and the negative electrode of the fourth diode D4, and the positive electrode of the fourth diode D4 is electrically connected to the integrated circuit U1 The output terminal is electrically connected. The input terminal of the integrated circuit U1 is grounded through the first capacitor C1, and the output terminal of the integrated circuit U1 is grounded through the second capacitor C2. In the embodiment of the present application, the voltage between the drain of the first field effect transistor Q3 and the parallel eighth resistor R8 and the ninth resistor R9 is the second power supply voltage VCC, and the voltage at the output end of the integrated circuit U1 is the first power supply voltage VDD.

It can be understood that when the hair dryer is in the working state, the drive signal PWR_ON input from one end of the third resistor R3 is at a high level, so that the first field effect transistor Q3 is turned on. The second power supply voltage VCC is equal to the battery voltage BAT+. The detection module 100 is electrically connected to the voltage dividing circuit module 200 to transmit the second power supply voltage VCC (ie, the battery voltage BAT+ of the battery) to the voltage dividing circuit module 200 .

For an embodiment, please refer to the schematic diagram of the circuit structure of the voltage divider circuit module 200 shown in FIG. 3 . In the embodiment of the present application, the voltage divider circuit module 200 includes tenth to twelfth resistors R10 - R12 and a third capacitor C3. It can be seen from FIG. 3 that the tenth resistor R10 and the eleventh resistor R11 are connected in series between the input terminal of the second power supply voltage VCC and the ground terminal GND, and one end of the twelfth resistor R12 is electrically connected to Connected between the tenth resistor R10 and the eleventh resistor R11, one end of the third capacitor C3 is electrically connected between the eleventh resistor R11 and the ground terminal GND, and the other end of the third capacitor C3 It is electrically connected to the other end of the twelfth resistor R12.

In the embodiment of the present application, due to the arrangement of the tenth resistor R10 and the eleventh resistor R11 , the voltages on the tenth resistor R10 , the eleventh resistor R11 and the twelfth resistor R12 are all lower than the second power supply voltage VCC . And after the voltage dividing circuit module 200 completes the voltage dividing, the voltage dividing circuit module 200 generates a corresponding detection voltage VSEN, the detection voltage VSEN is within the recognition range of the controller module 300, and the voltage dividing circuit module 200 will The detection voltage VSEN is transmitted to the controller module 300, which can compare the detection voltage VSEN with a first threshold. It can be understood that the detection voltage VSEN is obtained by dividing the voltage of the battery in the battery module 10 by the voltage divider circuit module 200. Therefore, the detection voltage VSEN also directly reflects the use of the hair dryer. The voltage of each battery in the battery module 10 during the process.

For an embodiment, please refer to the schematic diagram of the circuit structure of the controller module 300 shown in FIG. 4 . In the embodiment of the present application, the controller module 300 mainly includes a controller circuit U2 and its peripheral circuits, and the controller circuit U2 and the The peripheral circuits are electrically connected. The controller circuit U2 is used to process and comprehensively analyze the information input by each circuit module, and output a corresponding heating control signal to each execution circuit module, so that each execution circuit module can accurately realize its own function. In the embodiment of the present application, the peripheral circuit includes at least the thirteenth to sixteenth resistors R13-R16 and the fourth to twelfth capacitors C4-C12. Please refer to FIG. 4 for the connection relationship of the above electronic components. This will not be repeated here.

It can be seen from FIG. 4 that the detection voltage VSEN output by the voltage divider circuit module 200 is transmitted to the controller module 300, and the corresponding pins of the controller circuit U2 (for example, the leads of the controller circuit U2 shown in the figure) are transmitted to the controller module 300. Pin 3) receives, the controller module 300 can calculate the voltage of any battery according to the detected voltage VSEN. The controller module 300 compares the detection voltage VSEN with the first threshold, and triggers the generation of a heating control signal HEATER when it is determined that the detection voltage VSEN is smaller than the first threshold. The controller module 300 is electrically connected to the heating module 400, and transmits the heating control signal HEATER to the heating module 400 (for example, the signal HEATER is transmitted through pin 26 of the controller circuit U2 shown in the figure). to the heating module 400), the heating module 400 disconnects the path with the battery module 10 according to the heating control signal HEATER, that is, the battery module 10 stops supplying power to the heating module 400 and Make the blower stop blowing hot air.

In this embodiment of the present application, the value of the first threshold is between 3.0V-3.3V, that is, the value range of the first threshold is 3.0V-3.3V, for example, 3.1V, 3.15V V, 3.2V, 3.25V, or other value.

For an embodiment, please refer to the schematic diagram of the circuit structure of the heating module 400 shown in FIG. 5. In the embodiment of the present application, the heating module 400 shown mainly includes a seventeenth resistor R17, an eighteenth resistor R18, a heating wire Rw, a Six diodes D6 and the second field effect transistor Q4. One end of the seventeenth resistor R17 receives the heating control signal HEATER, the other end of the seventeenth resistor R17 is electrically connected to the gate of the second field effect transistor Q4, and the eighteenth resistor R18 One end of the resistor R18 is connected to the ground terminal, and the other end of the eighteenth resistor R18 is electrically connected to the gate of the second field effect transistor Q4. The second field effect transistor Q4 and the sixth diode D6 in the heating module 400 are connected in parallel in the circuit, which can reduce the loss of the battery during the power switching process and reduce all the power in the heating module 400. The current impact on the second field effect transistor Q4. The source of the second field effect transistor Q4 is connected to the ground terminal, the eighteenth resistor R18 is electrically connected between the gate and the source of the second field effect transistor Q4, the second field effect transistor The source of the transistor Q4 is also electrically connected to the anode of the sixth diode D6, and the drain of the second FET Q4 is connected to the cathode of the sixth diode D6 and the heating wire Between the positive poles of Rw, the negative pole of the heating wire Rw receives the battery voltage BAT+.

In the embodiment of the present application, the sixth diode D6 may be a Zener diode.

In the circuit diagram shown in FIG. 5 , when the heating control signal HEATER input to one end of the seventeenth resistor R17 is at a high level, the second field effect transistor Q4 can be turned on, and the battery voltage BAT+ supplies power to the heating module 400, thereby enabling the heating module 400 to work. At this time, the hair dryer can blow out hot air, that is, the hair dryer is in the hot air mode (ie, the first working mode). When the heating control signal HEATER input to one end of the seventeenth resistor R17 is at a low level, the second field effect transistor Q4 can be turned off, and the battery voltage BAT+ is stopped to the heating module 400 at this time. Power is supplied, so that the heating module 400 stops working. At this time, the hair dryer enters the cold air mode (ie, is in the second working mode).

In one embodiment, the heating control signal HEATER input at one end of the seventeenth resistor is a pulse width modulation (Pulse width modulation, PWM) signal, and the heating control signal HEATER enables the controller module 300 to control all The on-duty ratio of the second field effect transistor Q4 is reduced, thereby reducing the power supply current or voltage of the battery module 10 to the heating module 400, so that the power of the heating module 400 is reduced. At this time, the hair dryer Enter the second working mode.

It should be noted that, after the wireless hair dryer is converted from the hot air mode to the cold air mode due to the above reasons, on the premise that the battery module 10 of the wireless hair dryer is not charged, even if any battery in the battery module 10 is not charged At this time, the voltage is greater than or equal to the first threshold, and the wireless hair dryer still cannot blow hot air. That is, after the wireless hair dryer is converted from the hot air mode to the cold air mode due to the above reasons, the wireless hair dryer can enter the hot air mode only after the battery module 10 of the wireless hair dryer needs to be charged.

Please refer to FIG. 6 , which is a circuit block diagram of another hair dryer disclosed in an embodiment of the present application. As shown in FIG. 6 , the hair dryer provided in this embodiment of the present application includes a main control board 610 , a battery protection board 620 , a switch module 630 , a display module 640 , a motor 650 , a charging interface 660 , the battery module 10 , and the battery protection Circuit 20, the battery protection circuit 20 includes at least a detection module 100, a voltage divider circuit module 200, a controller module 300 and a heating module 400 as shown in FIG. 1 . The main control board 610 is electrically connected to the battery protection board 620 , the battery module 10 , the switch module 630 , the display module 640 , the motor 650 and the charging interface 660 respectively, the charging protection circuit 20 and the battery The protection board 620 is connected between the battery module 10 and the main control board 610 . In other embodiments of the present application, the charging protection circuit 20 may also be disposed on the battery protection board 620 or integrated on the main control board 610 .

In this embodiment, the main control board 610 is used for real-time detection of the voltage of the battery module 10 during charging or use. When the main control board 610 detects that the battery module 10 is overcharged or overdischarged In some cases, the main control board 610 is used to control the battery protection board 620 to stop charging the battery module 10 or control the battery module 10 to stop discharging. Therefore, the hair dryer of the present application can safely protect the battery of the hair dryer while ensuring its use function, avoid the phenomenon of micro-short circuit in the internal circuit of the wireless hair dryer caused by overcharging or over-discharging of the battery, and also avoid the aging of the wireless hair dryer or the phenomenon of over-discharge. Safety hazards caused by failures.

In other embodiments of the present application, the main control board 610 may further be provided with a delay circuit, and the delay circuit is used to distinguish surge current from short-circuit current.

In one embodiment, during the charging process of the wireless hair dryer, the main control board 610 detects the charging voltage of the battery module 10 and obtains that when the charging voltage of any battery in the battery module 10 is greater than the second threshold, the battery module 10 Stop charging to prevent overcharging. In this embodiment, the second threshold is between 4.1V-4.25V, that is, the value range of the second threshold is 4.1V-4.25V, for example, 4.15V, 4.2V, or other values.

In one embodiment, during the working process of the wireless hair dryer, when the main control board 610 detects the battery module 10 and obtains that the voltage of any battery in the battery module 10 is less than the preset third threshold, The main control board 610 controls the battery module 10 to stop discharging to prevent damage to the battery module 10 due to over-discharge, and displays the low battery status through the display module 640 to remind the user that the wireless hair dryer needs to be charged. In this embodiment, the third threshold is between 2.5V-3.0V, that is, the value range of the third threshold is 2.5V-3.0V, for example, 2.6V, 2.7V, 2.8 , 2.9V, or other value.

In one embodiment, in order to ensure the normal and safe use of the battery module 10, a detection device for recording the charging times of the battery module 10 is also provided on the wireless hair dryer. When the charging times of the battery module 10 recorded by the detection device is greater than or equal to the preset charging times threshold, it is determined that the hair dryer wireless hair dryer has reached the state of overuse, and the main control board 610 will stop charging the battery module 10 at this time. and discharge, and use this to achieve the safe use of wireless hair dryers. In this embodiment, the threshold for the number of charging times is 1000 times.

In one embodiment, the display module 640 is mainly used to display the current power and charging status of the wireless hair dryer, and the display module 640 can be powered by the main control board 610 . The main control board 610 is also used to control the operation of the motor 650, and the motor 650 is used to drive the fan blades of the fan to rotate, thereby realizing the blowing function of the wireless hair dryer. In one embodiment, the first working mode of the wireless hair dryer is divided into a first gear, a second gear and a third gear, and the voltage corresponding to the first gear is the first gear voltage, which is the same as the first gear. The voltage corresponding to the second gear is the second gear voltage, and the voltage corresponding to the third gear is the third gear voltage.

It can be understood that, when the controller module 300 determines that the voltage of the battery module 10 is greater than the voltage of the first gear, the wireless hair dryer works in the first gear, and when the controller module 300 determines that the voltage of the first gear is When the voltage of the battery module 10 is lower than the voltage of the first gear and higher than the voltage of the second gear, the wireless hair dryer is automatically switched from the first gear to the second gear; when the controller module 300 determines When the voltage to the battery module 10 is lower than the voltage of the second gear and higher than the voltage of the third gear, the wireless hair dryer is automatically switched from the second gear to the third gear; when the controller When the module 300 determines that the voltage of the battery module 10 is lower than the voltage of the third gear, the wireless hair dryer is automatically switched from the third gear to the second working mode. It can be understood that when the wireless hair dryer is in the first working mode, the temperature of the hot air blown by the wireless hair dryer can be reduced by adjusting the gear of the wireless hair dryer, and the temperature of the hot air is related to the voltage of the battery module 10 . proportionally lower. That is, when the voltage of the battery module 10 decreases, the temperature of the hot air of the wireless hair dryer also decreases synchronously. At this time, the gears of the wireless hair dryer are from the first gear to the third gear. direction to reduce the gear.

In this embodiment, the third gear voltage is also the first threshold value, that is, the value of the third gear voltage is also between 3.0V-3.3V, for example, 2.6V, 2.7V , 2.8, 2.9V, or other values.

Correspondingly, the first gear corresponds to the high-speed gear of the motor 650 , the second gear corresponds to the medium-speed gear of the motor 650 , and the third gear corresponds to the low-speed gear of the motor 650 . block. When the wireless hair dryer of the present application works in the first working mode (ie, the hot air mode), the speed of the hot air blown by the wireless hair dryer is adjusted by adjusting the rotational speed of the motor 650 , especially according to the speed of the hot air in the battery module 10 . The voltage level automatically adjusts the working position of the wireless hair dryer, and then automatically adjusts the speed of the hot air blown by the wireless hair dryer, which can avoid the poor user experience caused by the direct conversion from the hot air mode to the cold air mode, and at the same time prompt the user to need Charge the wireless hair dryer, thus increasing the range and user experience of the wireless hair dryer.

The charging interface 660 may be fixed on the main control board 610 , or may be independent of the main control board 610 . When the charging interface 660 is fixed on the main control board 610, the ports with positive and negative electrodes on the charging interface 660 are connected to the main control board 610, and the ports with positive and negative electrodes of the charging interface 660 can be connected with the positive and negative electrodes of the charging base. The negative terminal is connected. In this embodiment, a tact switch or an induction switch is provided on the charging base. When the charging base senses that the charging interface 660 of the wireless hair dryer is combined with the interface of the charging base, the switch module of the charging base is turned on, so that the The wireless hair dryer realizes the conduction of the charging path.

It should be pointed out that, in order to increase the use range and application scenarios of the wireless hair dryer, the present application realizes the wireless charging of the wireless hair dryer, in order to avoid the wireless hair dryer being unable to be charged normally due to the failure of the wireless charging circuit, or the failure of the battery module 10 to charge. If the wireless hair dryer cannot be used due to problems such as normal charging, or the temporary inability to replace the new battery module 10, the wireless hair dryer is also provided with a power cord, which is used to directly communicate with the market. The electric socket is connected, so that the wireless hair dryer can still achieve its blowing function after being connected to the mains socket.

In one embodiment, when the wireless hair dryer is in the charging state, the heating module 400 and the motor 650 stop working, and the wireless hair dryer can be removed from the charging base at any time, the wireless hair dryer after the removal exits the charging state, and resumes the work before charging model. For example, when the wireless hair dryer is in the hot air mode before charging, after the wireless hair dryer is charged and removed from the charging base, the wireless hair dryer returns to the hot air mode, that is, the wireless hair dryer continues to blow hot air at this time.

In other embodiments, when the wireless hair dryer exits the charging state, that is, when the wireless hair dryer is removed from the charging base, no matter what operating mode the wireless hair dryer is in, it is necessary to first turn off the power of the wireless hair dryer and restart the wireless hair dryer. The wireless hair dryer can start working again. For example, when the wireless hair dryer is in the hot air mode before charging, after the wireless hair dryer is fully charged and removed from the charging base, the wireless hair dryer cannot keep the state before charging and continues to blow hot air, but needs to be powered off and restarted. The cordless hair dryer cannot continue to work until the power is turned on. In this embodiment, by restarting the wireless hair dryer, it is possible to ensure that the user has a good experience, and to avoid a poor experience caused by the user not knowing the working mode before charging.

In one embodiment, the wireless hair dryer can also be controlled by detecting the real-time current of the wireless hair dryer or the real-time temperature of the wireless hair dryer. Or described as, when the wireless hair dryer is in the first working mode and the current of the wireless hair dryer reaches a preset current threshold, the wireless hair dryer automatically switches from the first working mode to the second working mode. Likewise, when the wireless hair dryer is in the first working mode and the real-time temperature of the wireless hair dryer reaches the preset temperature threshold, the wireless hair dryer also automatically switches from the first working mode to the second working mode. That is, by monitoring the current of the wireless hair dryer or the temperature of the wireless hair dryer in real time, the wireless hair dryer can also be protected.

It should be understood that the application of the present application is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above descriptions, and all these improvements and transformations should belong to the protection scope of the appended claims of the present application.

Claims

A battery protection circuit is characterized in that it is electrically connected to a battery module composed of a plurality of batteries, and the battery protection circuit includes a detection module, a controller module and a heating module;

The detection module detects the parameters of each of the batteries in the battery module;

The controller module generates a heating control signal when the detected parameter of the battery is less than a first threshold;

The heating module switches the device where the heating module is located from the first working mode to the second working mode according to the heating control signal.
The battery protection circuit according to claim 1, further comprising a motor, and the motor and the heating module adjust the working conditions according to the heating control signal, so that the device where the heating module is located is operated by the first mode switches to the second operating mode, or,

The controller module generates a motor control signal when the detected parameter of the battery is less than the first threshold;

The heating module switches the device where the heating module is located from the first working mode to the second working mode according to the motor control signal.
The battery protection circuit according to claim 1, wherein the detection module is connected to the battery module and the controller module respectively, and the detection module transmits the parameters of the battery to the controller module;

And/or, the heating module is respectively connected to the controller module and the battery module, and the controller module sends the heating control signal to the heating module.
The battery protection circuit of claim 1, wherein the device where the heating module is located comprises a hair dryer.
The battery protection circuit according to claim 1, wherein the heating module disconnects the power supply path between the battery module and the heating module according to the heating control signal, so that the wireless hair dryer is operated by the heating module. The first working mode is switched to the second working mode.
The battery protection circuit of claim 1, wherein the power of the first working mode is greater than the power of the second working mode.
The battery protection circuit according to claim 1, wherein the detection module is further configured to realize conduction or disconnection between the battery module and the controller module, when the wireless hair dryer stops working when the battery module is disconnected from the controller module through the detection module.
The battery protection circuit according to claim 1, wherein the detection module is a voltage detection module, and the parameter is the voltage of the battery.
The battery protection circuit according to claim 1, wherein the battery protection circuit further comprises a voltage divider circuit module, the voltage divider circuit module is electrically connected to the detection module and the controller module, respectively, and the The voltage divider circuit module is configured to receive the voltage detected by the detection module, perform voltage division processing on the detected voltage to generate a detection signal, and transmit the detection signal to the controller module.
The battery protection circuit according to claim 1, wherein the heating module comprises a switch unit and a heating unit, and the switch unit is configured to control the heating unit by the battery module based on the heating control signal The heating unit is configured to convert the electric energy provided by the battery module into heat energy.
The battery protection circuit of claim 10, wherein when the heating control signal is at a first level, the switch unit stops working at the first level, and the battery module stops or limits supplying power to the heating unit, so that the device where the heating module is located enters the second working mode;

Or, the heating control signal is a pulse signal, and the controller adjusts the duty cycle of the pulse signal, and the pulse signal controls the turn-on duty cycle of the second field effect transistor, so that the heating module is located where the heating module is located. The device enters the second operating mode.
The battery protection circuit according to claim 1, wherein the first working mode includes a second gear and a third gear, the voltage corresponding to the second gear is the second gear voltage, and The voltage corresponding to the third gear is the third gear voltage;

When the controller module determines that the voltage of the battery module is lower than the second gear voltage and higher than the third gear voltage, the wireless hair dryer works in the third gear;

When the controller module determines that the voltage of the battery module is lower than the third gear voltage, the wireless hair dryer operates in the second working mode, wherein the third gear voltage is equal to the third gear voltage the first threshold.
The battery protection circuit according to claim 12, wherein the first working mode further comprises a first gear, and the voltage corresponding to the first gear is the first gear voltage,

When the controller module determines that the voltage of the battery module is greater than the voltage of the first gear, the wireless hair dryer works in the first gear;

When the controller module determines that the voltage of the battery module is lower than the first gear voltage and higher than the second gear voltage, the wireless hair dryer works in the second gear; The first threshold is between 3.0V-3.3V.
The battery protection circuit according to claim 1, wherein the first working mode is a hot air mode, and the second working mode is a cold air mode.
A hair dryer is characterized in that it includes a battery protection circuit and a battery module, the battery protection circuit is electrically connected to a battery module composed of a plurality of batteries, and the battery protection circuit includes a detection module, a controller module and a heating module. module;

The detection module detects the parameters of each of the batteries in the battery module;

The controller module generates a heating control signal when the detected parameter of the battery is less than the first threshold;

The heating module switches the device where the heating module is located from the first working mode to the second working mode according to the heating control signal.
The hair dryer of claim 15, wherein the heating module disconnects a power supply path between the battery module and the heating module according to the heating control signal, so that the hair dryer is powered by the first heating module. The working mode is switched to the second working mode, wherein the power of the first working mode is greater than the power of the second working mode.
The hair dryer of claim 15, wherein the first working mode includes a first gear, a second gear and a third gear, and the voltage corresponding to the first gear is the first gear voltage, the voltage corresponding to the second gear is the second gear voltage, and the voltage corresponding to the third gear is the third gear voltage;

When the controller module determines that the voltage of the battery module is greater than the voltage of the first gear, the hair dryer works in the first gear;

When the controller module determines that the voltage of the battery module is lower than the voltage of the first gear and higher than the voltage of the second gear, the hair dryer is automatically switched from the first gear to the second gear. the second gear;

When the controller module determines that the voltage of the battery module is lower than the voltage of the second gear and higher than the voltage of the third gear, the hair dryer is automatically switched from the second gear to the second gear. the third gear;

When the controller module determines that the voltage of the battery module is lower than the voltage of the third gear, the hair dryer is automatically switched from the third gear to the second working mode, wherein the The third gear voltage is equal to the first threshold.
The hair dryer of claim 15, wherein the hair dryer further comprises a main control board and a display module, and the main control board is electrically connected to the battery module, the battery protection circuit and the display module, respectively. connected, the display module is used to display the power and charging status of the hair dryer.
The hair dryer of claim 18, wherein the main control board detects the charging voltage of the battery module, and detects that the charging voltage of any battery in the battery module is greater than a preset value At the second threshold, the battery module stops charging; or,

The main control board detects the charging voltage of the battery module, and stops discharging the battery module when detecting that the charging voltage of any battery in the battery module is less than a preset third threshold.
The hair dryer of claim 19, wherein the second threshold is between 4.1V-4.25V, and the third threshold is between 2.5V-3.0V.