Temperature control circuit of hand warmer

Abstract

The utility model discloses a temperature control circuit of a hand warmer, and relates to the technical field of hand warmer control, and the temperature control circuit of the hand warmer comprises a heating unit used for heating; the at least one key unit is used for outputting a first key signal based on a first operation of a user and outputting a second key signal based on a second operation of the user; and the main control unit is used for outputting a first control signal when receiving the first key signal to control the heating unit to heat to a first working temperature and to work under corresponding driving power according to the number of times of receiving the second key signal, and the heating circuit heats to a second working temperature. Thus, when a user controls the heating unit to heat to the first working temperature through the first operation and can also operate the key unit through the second operation, the corresponding driving power is selected according to the number of times of receiving the second key signal, and the heating unit is driven, so that the user can avoid tedious multiple operations, and the use convenience of the user is improved.

Description

Technical Field

[0001] This utility model relates to the field of hand warmer control technology, and in particular to a temperature control circuit for a hand warmer. Background Technology

[0002] Hand warmers, as convenient warmth-keeping devices, are widely popular during the cold season. Currently, most hand warmers on the market offer multiple temperature settings to meet the individual needs of different users. However, existing multi-level hand warmers have certain inconveniences in actual use. Specifically, users need to repeatedly press buttons to cycle through different driving power levels (such as low, medium, and high power) until the desired power is found, at which point the hand warmer will operate and achieve the desired heating temperature. This process is not only laborious but may also require users to repeat the operation multiple times while searching for the target setting, increasing unnecessary waiting time and user dissatisfaction.

[0003] Furthermore, for elderly users or those with limited finger dexterity, frequently pressing small buttons is not only difficult to operate, but may also lead to accidental shutdown or other problems due to improper operation. Therefore, designing a more user-friendly and easy-to-use temperature adjustment mechanism for hand warmers has become an urgent problem to be solved. Utility Model Content

[0004] The main purpose of this invention is to propose a temperature control circuit for a hand warmer, which aims to solve the problem that hand warmers with multiple temperature adjustment modes require multiple button presses to adjust the power to the target level, thus seriously affecting the user experience.

[0005] To achieve the above objectives, the present invention proposes a temperature control circuit for a hand warmer, the temperature control circuit of which includes:

[0006] Heating unit for heating;

[0007] At least one button unit is used for a first button signal output based on a first user operation and a second button signal output based on a second user operation.

[0008] The main control unit is electrically connected to the button unit and the heating unit, and the main control unit is equipped with multiple temperature adjustment modes;

[0009] The main control unit is used to output a first control signal when it receives a first button signal, so as to control the heating unit to heat up to a first working temperature;

[0010] The main control unit is further configured to control the heating unit to operate at a corresponding driving power based on the number of times the second button signal is received, so that the heating unit heats up to a second operating temperature, wherein the second operating temperature is less than or equal to the first operating temperature.

[0011] In one embodiment, the button unit includes:

[0012] A first button subunit, electrically connected to the main control unit, is used to output a first button signal based on a user's pressing operation;

[0013] The second button subunit is electrically connected to the main control unit and is used to output a second button signal based on the user's pressing operation;

[0014] The main control unit is configured with multiple temperature adjustment modes. When the first button signal is received, the main control unit is also used to output the first control signal to control the heating unit to heat up to the first working temperature, or to select the driving power of the corresponding level of the multiple temperature adjustment modes according to the number of times the second button signal is received, so as to control the heating unit to heat up.

[0015] In one embodiment, the main control unit is further configured to power on or power off when the first key signal or the second key signal reaches a preset time threshold.

[0016] In one embodiment, the temperature control circuit of the hand warmer further includes:

[0017] The first prompting unit is electrically connected to the main control unit and is used to prompt the user about the operating temperature of the heating unit; the first prompting unit includes an indicator light and / or a display screen.

[0018] In one embodiment, the first prompting unit includes five indicator lights electrically connected to the main control unit, which is configured with five temperature adjustment modes. The main control unit is configured to, when receiving the second button signal once, drive the heating unit to heat according to the first level of the five temperature adjustment modes and activate one indicator light; when receiving the second button signal twice, drive the heating unit to heat according to the second level of the five temperature adjustment modes and activate two indicator lights; when receiving the second button signal three times, drive the heating unit to heat according to the second level of the five temperature adjustment modes and activate two indicator lights; when receiving the second button signal three times, drive the heating unit to heat according to the first level of the five temperature adjustment modes and activate one indicator light. In the temperature control mode, the third power setting drives the heating unit to heat and activates the three indicator lights. The main control unit, upon receiving the second button signal four times, drives the heating unit to heat according to the fourth power setting in the five-level temperature control mode and activates the four indicator lights. The main control unit, upon receiving the second button signal five times, drives the heating unit to heat according to the fifth power setting in the five-level temperature control mode and activates the five indicator lights. The power values ​​for the first, second, third, fourth, and fifth power settings are all different.

[0019] In one embodiment, the button unit further includes:

[0020] The third button subunit is used to output a third button signal based on the user's pressing operation;

[0021] The lighting unit is electrically connected to the main control unit and is used to output a lighting control signal when the main control unit receives the third button signal, so as to control the lighting unit to perform lighting.

[0022] In one embodiment, the heating unit includes:

[0023] At least one switching element and a heating resistor;

[0024] The switching element is electrically connected to the main control unit, ground, and heating resistor respectively. The main control unit is also used to adjust the duty cycle of the PWM signal to a first preset value when it receives the first button signal, so as to output it to the switching element and control the heating unit to heat up to the first working temperature, or to adjust the duty cycle of the PWM signal successively according to the number of times the second button signal is received, so as to output it to the switching element and control the heating unit to heat up to the second working temperature.

[0025] In one embodiment, the temperature control circuit of the hand warmer further includes:

[0026] Batteries used to output electrical energy from batteries;

[0027] The second prompting unit is electrically connected to the main control unit and is used to prompt the user about the battery level. The second prompting unit includes an indicator light and / or a display screen.

[0028] A power detection unit, wherein the sampling end of the power detection unit is electrically connected to the battery, and the output end of the power detection unit is electrically connected to the main control unit, for detecting the voltage of the battery power and then outputting a power detection signal to the main control unit;

[0029] The main control unit is equipped with a power level indicator mode. The main control unit is also used to control the corresponding indicator light to work in the power level indicator mode according to the received power level detection signal, and / or to control the display screen to work in the power level indicator mode according to the received power level detection signal.

[0030] In one embodiment, the temperature control circuit of the hand warmer further includes:

[0031] A temperature detection unit is provided, wherein the sampling end of the temperature detection unit is electrically connected to the battery, and the output end of the temperature detection unit is electrically connected to the main control unit. The temperature detection unit is used to detect the temperature of the battery and output a battery temperature detection signal so that when the main control unit detects that the battery temperature is too high based on the received battery temperature detection signal, it stops the battery from outputting battery power.

[0032] In one embodiment, the temperature control circuit of the hand warmer further includes:

[0033] A charging unit is provided, wherein the input terminal of the charging unit is connected to an external power source, and the output terminal of the charging unit is electrically connected to the battery. The charging unit is used to convert the voltage of the external power source to output charging energy to charge the battery.

[0034] The technical solution of this utility model employs a temperature control circuit for a hand warmer. The temperature control circuit includes: a heating unit for heating; at least one button unit for outputting a first button signal based on a first user operation and a second button signal based on a second user operation; and a main control unit electrically connected to both the button unit and the heating unit. The main control unit outputs a first control signal upon receiving the first button signal to control the heating unit to heat to a first operating temperature. The main control unit also selects the power of the multi-level temperature adjustment mode based on the number of times the second button signal is received to drive the heating unit. Thus, when the user outputs the first button signal through the first operation button unit, the heating unit is controlled to heat to the first operating temperature. Furthermore, when the user operates the button unit, the main control unit selects the corresponding driving power based on the number of times the second button signal is received to drive the heating unit to heat to a second target temperature, where the second operating temperature is less than or equal to the first operating temperature. This avoids tedious multiple operations and improves user convenience. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0036] Figure 1 A system block diagram of an embodiment of the temperature control circuit for the hand warmer provided by this utility model;

[0037] Figure 2 A circuit diagram of the heating unit and temperature detection unit in one embodiment of the temperature control circuit of the hand warmer provided by this utility model;

[0038] Figure 3 A circuit diagram of the charging unit in one embodiment of the temperature control circuit of the hand warmer provided by this utility model;

[0039] Figure 4 A circuit diagram of the main control unit, lighting unit, and button unit in one embodiment of the temperature control circuit of the hand warmer provided by this utility model;

[0040] Figure 5 The circuit diagram of the battery in one embodiment of the temperature control circuit of the hand warmer provided by this utility model.

[0041] Explanation of icon numbers:

[0042] 1. Main control unit; 2. Button unit; 21. First button sub-unit; 22. Second button sub-unit; 23. Third button sub-unit; 3. Heating unit; 31. Switch element; 4. First indicator unit; 5. Second indicator unit; 6. Battery; 7. Power detection unit; 8. Temperature detection unit; 9. Charging unit; 10. Lighting unit.

[0043] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0044] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0045] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0046] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0047] refer to Figure 1 This utility model proposes a temperature control circuit for a hand warmer, which includes:

[0048] Heating unit 3 for heating;

[0049] At least one button unit 2 is used for a first button signal output based on a first user operation and a second button signal output based on a second user operation;

[0050] Main control unit 1, which is electrically connected to the button unit 2 and the heating unit 3;

[0051] The main control unit 1 is used to output a first control signal when it receives a first button signal, so as to control the heating unit 3 to heat up to a first working temperature;

[0052] The main control unit 1 is further configured to control the heating unit 3 to operate at a corresponding driving power based on the number of times the second button signal is received, so that the heating unit 3 heats up to a second operating temperature, wherein the second operating temperature is less than or equal to the first operating temperature.

[0053] In this embodiment, the temperature control circuit of the hand warmer can be powered by an internal energy storage device or an external power supply. The heating unit 3 can be implemented by a PTC heating element or an electric heating wire. After receiving the control signal from the main control unit 1, the heating unit 3 can generate heat to heat the hand warmer. The main control unit 1 sets multiple temperature adjustment modes, each containing multiple preset levels. Each level is achieved by an increasing PWM signal duty cycle. The main control unit 1 controls the driving power of the heating unit 3 by adjusting the PWM signal duty cycle, thereby adjusting its operating temperature. Alternatively, power drive units corresponding to the number of levels in the multiple temperature adjustment modes can be set. By sending multiple different switching signals, the corresponding power drive units are driven to output different power of electrical energy, thereby adjusting the operating temperature of the heating unit 3. The button unit 2 can be implemented by mechanical buttons, touch buttons, or inductive buttons. Mechanical buttons are preferred to avoid accidental touches when using the hand warmer. The main control unit 1 can be, for example, an MCU (Microcontroller Unit) or a DSP (Digital Signal Processor). The main control unit 1 stores the duty cycle of the PWM signal for multiple temperature adjustment modes, and controls the driving power of the heating unit 3 by reading the duty cycle of the selected mode to adjust the temperature of the hand warmer.

[0054] The button unit 2 can be configured as one or more. For example, when there is only one button unit 2, each time the user presses it, a brief level signal is output. The main control unit 1 selects the corresponding driving power according to the number of times the level signal is received, so that the heating unit 3 heats at the second working temperature. When the user continuously presses the button unit 2, a continuous level signal is output. When the continuous level signal reaches a preset time (e.g., 2 seconds), the main control unit 1 outputs a first control signal to control the heating unit 3 to heat up to the first working temperature. Here, if the driving power of the heating unit 3 at the first working temperature is the same as the highest driving power that the heating unit 3 can select at the second working temperature, the user can quickly select the highest driving power for driving in the first operation mode, saving the tedious step-by-step selection process and improving the user experience.

[0055] In one embodiment, the button unit includes:

[0056] The first button subunit 21 is electrically connected to the main control unit 1 and is used to output a first button signal based on the user's pressing operation.

[0057] The second button subunit 22 is electrically connected to the main control unit 1 and is used to output a second button signal based on the user's pressing operation.

[0058] The main control unit 1 is configured with multiple temperature adjustment modes. When the first button signal is received, the main control unit 1 is also used to output the first control signal to control the heating unit to heat up to the first working temperature, or to select the driving power of the corresponding level of the multiple temperature adjustment modes according to the number of times the second button signal is received, so as to control the heating unit to heat up.

[0059] In this embodiment, the user's first operation is specifically pressing the first button subunit 21, and the user's second operation is specifically pressing the second button subunit 22. Both the first and second button signals are brief level signals. The first control signal output by the main control unit 1 to the heating unit 3 is the drive power output by the main control unit 1 at the highest level of the multi-level temperature adjustment mode. As a result, the heating unit 3 heats up to the first working temperature, which is the temperature corresponding to the heating unit 3 when working at the highest level in the multi-level temperature adjustment mode. When the main control unit 1 receives the second button signal, the main control unit 1 selects the PWM signal duty cycle of the corresponding level in the multi-level temperature adjustment mode according to the number of times the second button signal is received. Based on the selected PWM signal duty cycle, the main control unit 1 outputs the corresponding drive power to the heating unit to control the heating unit 3 to heat up, thereby adjusting the temperature of the hand warmer. The second working temperature is the temperature corresponding to a certain level that the user expects to work in the multi-level temperature adjustment mode.

[0060] For example, five temperature control modes can be set, with the following PWM signal duty cycles for each mode: Level 1: 50%, driving heating unit 3 to operate at a heating temperature of 38-40°C; Level 2: 60%, driving heating unit 3 to operate at a heating temperature of 42-44°C; Level 3: 70%, driving heating unit 3 to operate at a heating temperature of 46-48°C; Level 4: 80%, driving heating unit 3 to operate at a heating temperature of 50-52°C; Level 5: 90%, driving heating unit 3 to operate at a heating temperature of 54-56°C. Upon receiving the second button signal, the main control unit 1 sends out the corresponding PWM signal to control the heating unit 3 to operate. Therefore, upon receiving a subsequent second button signal, the multi-level temperature adjustment mode is progressively increased according to the number of times the second button signal is received, until the highest level of the multi-level temperature adjustment mode is reached. If the second button signal is received again, it returns to the lowest level, and so on. Thus, the user can select the voltage signal with the duty cycle of the PWM signal for the corresponding level based on the number of times the second button subunit 22 is pressed, thereby controlling the heating unit 3 to heat and adjust the temperature of the hand warmer. The R&D personnel can also, according to actual needs, keep the duty cycle of the PWM signal driving the heating unit 3 in the main control unit 1 consistent with the duty cycle of the PWM signal driving the heating unit 3 in the lowest level of the multi-level temperature adjustment mode. The main control unit 1 progressively decreases the level of the multi-level temperature adjustment mode according to the number of times the second button signal is pressed, until the lowest level of the multi-level temperature adjustment mode is reached, and then returns to the highest level.

[0061] Furthermore, the main control unit 1 is also used to power on or power off when it receives the first key signal or the second key signal and the time threshold is reached.

[0062] In this embodiment, when the user operates the first button subunit 21 or the second button subunit 22 for a preset time threshold (e.g., 2 seconds), the main control unit 1 controls the main control unit 1 to switch working states according to the conduction duration of the received first button signal and second button signal, so as to switch from the off state to the on state, or from the on state to the off state. In this way, the temperature control circuit of the hand warmer can not only effectively save energy, but also effectively avoid frequent power-on or power-off caused by the user accidentally touching the button.

[0063] In one embodiment, the temperature control circuit of the hand warmer further includes:

[0064] The first prompting unit 4 is electrically connected to the main control unit 1 and is used to prompt the user about the working temperature of the heating unit 3; the first prompting unit 4 includes an indicator light and / or a display screen.

[0065] In this embodiment, the first prompting unit 4 can provide prompts using indicator lights of different colors and / or display different numbers of indicator lights. The first prompting unit 4 starts or stops working by receiving control signals from the main control unit 1. For example, when the heating unit 3 is at the temperature driven by the voltage of the PWM duty cycle of the first level of the multi-level temperature adjustment mode, the indicator light displays green and / or the first indicator light is on; when the heating unit 3 is at the temperature driven by the second level of the multi-level temperature adjustment mode, the indicator light displays yellow and / or the second indicator light is on; when the operating temperature of the heating unit 3 is at the temperature driven by the third level of the multi-level temperature adjustment mode, the indicator light displays red and / or the third indicator light is on, and the settings for other levels can be deduced similarly. The first prompting unit 4 can also provide voice prompts to the user through a voice IC (WT588F) and a microphone; the first prompting unit 4 can also provide text prompts through a display screen, such as displaying "low temperature", "medium temperature", "high temperature", etc., so that the user can more intuitively understand the current working status of the heating unit 3. The display screen can be implemented using LCD or OLED displays, etc.

[0066] Furthermore, the first prompt unit 4 is configured with multiple indicator lights, and the multi-level temperature adjustment mode also has a multi-level prompt function with the same number of levels, that is, each level corresponds to a specific prompt method. The main control unit 1 is also used to control the corresponding indicator lights to work according to the number of times the second button signal is received, using the multi-level temperature adjustment mode.

[0067] In this embodiment, the multi-level temperature adjustment mode includes, but is not limited to, indicating the light color and number of indicator lights mentioned above. It can also be indicated by controlling the light frequency and sequence of the indicator lights. For example, when the user presses the second button subunit 22 for the first time, the main control unit 1 controls the first indicator light to flash at a low frequency of once per second, indicating that the hand warmer has entered the first level of the multi-level temperature adjustment mode. When the user presses the second button subunit 22 for the second time, the main control unit 1 controls the first and second indicator lights to flash alternately at a frequency of twice per second, indicating that the hand warmer has entered the second level of the multi-level temperature adjustment mode. When the user presses the second button subunit 22 for the third time, the main control unit 1 sequentially illuminates the first, second, and third indicator lights at a frequency of three times per second, indicating that the hand warmer has entered the third level of the multi-level temperature adjustment mode.

[0068] For further details, please refer to... Figure 4The first prompting unit 4 includes five indicator lights electrically connected to the main control unit 1. The main control unit 1 is configured with five temperature adjustment modes. When the second button signal is received once, the main control unit 1 drives the heating unit to heat according to the first level of the five temperature adjustment modes and activates one indicator light. When the second button signal is received twice, the main control unit 1 drives the heating unit to heat according to the second level of the five temperature adjustment modes and activates two indicator lights. When the second button signal is received three times, the main control unit 1 activates the heating unit according to the first level of the five temperature adjustment modes and activates two indicator lights. The third driving power in the five-level temperature control mode drives the heating unit to heat and activates the three indicator lights. The main control unit 1, when receiving the second button signal four times, drives the heating unit to heat according to the fourth driving power in the five-level temperature control mode and activates the four indicator lights. The main control unit 1, when receiving the second button signal five times, drives the heating unit to heat according to the fifth driving power in the five-level temperature control mode and activates the five indicator lights. The driving power values ​​for the first, second, third, fourth, and fifth driving powers are all different.

[0069] In this embodiment, the five-level temperature control mode also has a five-level prompt function. By setting five prompt levels, the main control unit 1 controls the heating component to drive the prompt temperature according to the corresponding drive power. The prompt temperatures for each level are as follows: the first level indicates that the heating temperature of the heating unit 3 is 38-40°C; the second level indicates that the heating temperature of the heating unit 3 is 42-44°C; the third level indicates that the heating temperature of the heating unit 3 is 46-48°C; the fourth level indicates that the heating temperature of the heating unit 3 is 50-52°C; the fifth level indicates that the heating temperature of the heating unit 3 is 50-52°C; the sixth level indicates that the heating temperature of the heating unit 3 is 50-52°C; the seventh level indicates that the heating temperature of the heating unit 3 is 50-52°C; the eighth level indicates that the heating temperature of the heating unit 3 is 50-52°C; the ninth level indicates that the heating temperature of the heating unit 3 is 50-52°C; the tenth level indicates that the heating temperature of the heating unit 3 is 50-52°C; the twentieth ... The heating unit 3 operates at a temperature of 54-56°C. The five indicator lights illuminate one, two, three, four, or five lights respectively, depending on the operating level. Users can quickly determine the current heating temperature range by observing the number of lit indicator lights. The five indicator lights can be configured as dual-color lights. When the hand warmer needs to indicate other operating states, one color of the indicator light can be used to indicate the operating level, while the other color indicates other operating states, thus reducing the number of indicator lights used and increasing their utilization rate.

[0070] In one embodiment, the temperature control circuit of the hand warmer further includes:

[0071] The third button subunit 23 is used to output a third button signal based on the user's operation;

[0072] The lighting unit 10 is electrically connected to the main control unit 1. When the main control unit 1 receives the third button signal, it outputs a lighting control signal to control the lighting unit 10 to perform lighting.

[0073] In this embodiment, the temperature control circuit of the hand warmer also includes a third button subunit 23 for outputting a third button signal. The third button subunit 23 can be implemented by a mechanical button, a touch button, or a sensor button, etc. The lighting unit 10 can be implemented by an indicator light. After receiving the third button signal, the main control unit 1 illuminates and outputs a lighting control signal to control the lighting unit 10 to illuminate. This provides convenience for users when using the hand warmer at night or in low-light environments. In addition, the main control unit 1 can be set to perform lighting or extinguishing operations when the conduction time of the received third button signal (level signal) reaches a preset time threshold, so as to avoid users accidentally touching the third button subunit 23 and causing frequent changes in the working state of the lighting unit 10.

[0074] For details, please refer to Figure 4 The lighting unit 10 is a lighting lamp D2, which is installed inside the housing of the hand warmer. The light emitted by the lamp can pass through the light-transmitting hole on the housing to provide illumination.

[0075] In one embodiment, the heating unit 3 includes:

[0076] At least one switching element 31 and a heating resistor R7;

[0077] The switching element 31 is electrically connected to the main control unit 1, the ground terminal, and the heating resistor R7 respectively. The main control unit is also used to adjust the duty cycle of the PWM signal to a first preset value when it receives the first button signal, so as to output it to the switching element and control the heating unit to heat up to the first working temperature, or to adjust the duty cycle of the PWM signal successively according to the number of times the second button signal is received, so as to output it to the switching element and control the heating unit 3 to heat up to the second working temperature.

[0078] In this embodiment, the switching element 31 can be implemented using one or more electronic components such as MOSFETs, IGBTs, or relays to switch the operating state of the heating unit 3. When the main control unit 1 receives the first button signal, it adjusts the duty cycle of the PWM (Pulse Width Modulation) signal to a first preset value and outputs the PWM signal to the switching element, thereby controlling the heating unit 3 to heat up to the first operating temperature. The driving power at the first operating temperature is the same as the highest driving power that the heating unit 3 can select at the second operating temperature. Simultaneously, the main control unit 1 adjusts the duty cycle of the PWM signal sequentially according to the number of times the second button signal is received, based on the multi-level temperature adjustment mode, and outputs the adjusted PWM signal to the switching element 31 to control the heating unit 3 to heat up to the second operating temperature. This temperature adjustment method is not only flexible and convenient but also effectively avoids the shortcomings of traditional hand warmers, which offer only a single temperature and cannot meet the diverse needs of users. In this embodiment, by using a MOSFET as the switching element 31, precise control of the heating unit can be achieved, improving the stability and reliability of the circuit.

[0079] Further, please refer to Figure 2 The switching element 31 is configured as a dual-channel MOSFET Q4, and the heating unit 3 includes:

[0080] Dual-channel MOSFET Q4 and heating resistor R7;

[0081] The second terminal of the dual-channel MOSFET Q4 is electrically connected to the control terminal of the main control unit 1. The first and third terminals of the dual-channel MOSFET Q4 are grounded. The fourth terminal of the dual-channel MOSFET Q4 is electrically connected to the drive terminal of the main control unit 1 and the heating resistor R7, respectively. The fifth terminal of the dual-channel MOSFET Q4 is electrically connected to the drive terminal of the main control unit 1 and the heating resistor R7, respectively.

[0082] In this embodiment, the heating resistor R7 is used to receive the PWM signal with the corresponding duty cycle output by the main control unit 1 for heating when the dual-channel MOS transistor is turned on.

[0083] In one embodiment, the temperature control circuit of the hand warmer further includes:

[0084] Battery 6 is used to output battery power;

[0085] The second prompt unit 5 is electrically connected to the main control unit 1 and is used to prompt the user about the battery level of the 6.

[0086] The power detection unit 7 has a sampling end that is electrically connected to the battery 6 and an output end that is electrically connected to the main control unit 1. It is used to detect the voltage of the battery power and then output a power detection signal to the main control unit 1.

[0087] The main control unit 1 is equipped with a power level indicator mode. The main control unit 1 is also used to control the corresponding indicator light to work in the power level indicator mode according to the received power level detection signal, and / or to control the display screen to work in the power level indicator mode according to the received power level detection signal.

[0088] In this embodiment, the power detection unit 7 can be implemented through a voltage divider network circuit or a voltage detection chip. The main control unit 1 determines, based on the received power detection signal, that the voltage of the battery 6 has reached a certain preset voltage threshold range, and sends a power warning signal accordingly. This signals the corresponding second warning unit 5 to operate. The second warning unit 5 can be implemented through the first warning unit 4 or other units such as indicator lights to alert the user to the battery level of the 6. For example, when the first button subunit 21 or the second button subunit is double-clicked, the main control unit 1 receives the first button signal or the second button signal twice within a preset power warning time (e.g., 2 seconds). The main control unit 1 generates and outputs a power level indicator signal to the first indicator unit 4 based on the power level detection signal, controlling the operation of the first indicator unit 4. If the first indicator unit 4 is configured to use a voice IC and microphone combination for voice prompts, the main control unit 1 will verbally indicate the power level of the battery 6 based on the received power level detection signal. Alternatively, if the first indicator unit 4 has multiple indicator lights, the power level of the battery 6 can be indicated by the number of indicator lights displayed. For example, when there are five indicator lights, the second indicator unit 5 can also display text prompts on the screen, such as "low power," "medium power," and "high power," so that the user can more intuitively understand the current working status of the heating unit 3. The display screen can be implemented using an LCD screen or an OLED screen, etc.

[0089] For further details, please refer to... Figure 4 The five indicator lights LED1 to LED5, if the first prompt unit 4 is set to five indicator lights and set to dual-color lights, one color of the indicator light can be used to indicate the temperature level, and the other color can be used to indicate the battery level of the hand warmer. Specifically, the dual-color lights are set to red and blue dual-color lights. The red light of the five dual-color lights is used to indicate the temperature level in the five-level temperature adjustment mode to indicate the working temperature to the user, and the blue light of the five dual-color lights is used to indicate the battery level in the battery level indication mode to indicate the battery level.

[0090] The main control unit 1 is also used to receive the first button signal or the second button signal twice within a preset time (e.g., 2 seconds) to indicate the battery level. The main control unit 1 controls the corresponding blue lights to work according to the battery level detection signal. For example, when the battery 6 has 100% battery level, all blue indicator lights will light up or flash to indicate the battery level; when the battery 6 has 80% battery level, four blue indicator lights will light up or flash to indicate the battery level; when the battery 6 has 60% battery level, three blue indicator lights will light up or flash to indicate the battery level; when the battery 6 has 40% battery level, two blue indicator lights will light up or flash to indicate the battery level; when the battery 6 has 20% battery level, only one blue indicator light will light up or flash to indicate the battery level, thus intuitively displaying the remaining battery level of the battery 6.

[0091] In one embodiment, the temperature control circuit of the hand warmer further includes:

[0092] Temperature detection unit 8, the sampling end of temperature detection unit 8 is electrically connected to battery 6, and the output end of temperature detection unit 8 is electrically connected to main control unit 1. It is used to detect the temperature of battery 6 and output battery 6 temperature detection signal. When main control unit 1 detects that the temperature of battery 6 is too high according to the received battery 6 temperature detection signal, it stops battery 6 from outputting battery power.

[0093] In this embodiment, the temperature detection unit 8 can be implemented using a temperature sensor such as an NTC resistor or a thermistor. One end of the temperature sensor is grounded, and the other end is connected to an analog input port of the main control unit 1. The main control unit 1 obtains the temperature information of the battery 6 by reading the voltage value of the analog input port. When the temperature of the battery 6 is too high and exceeds the preset safety range, the main control unit 1 will immediately cut off the output of the battery 6 and stop supplying power to the heating unit 3 or other electrical components to prevent safety hazards caused by overheating of the battery 6 and ensure the safe use of the product.

[0094] For details, please refer to Figure 2 The temperature detection unit 8 is specifically an NTC resistor. The NTC resistor is connected to the line between the battery 6 and the connector CON3. The connector CON3 is electrically connected to the main control unit 1. By using the preset temperature threshold, the main control unit 1 can intelligently determine whether the battery 6 is in an overheated state and take corresponding protective measures.

[0095] In one embodiment, the temperature control circuit of the hand warmer further includes:

[0096] The charging unit 9 has an input terminal connected to an external power source and an output terminal connected to the battery 6. It is used to convert the voltage of the external power source to output charging energy to charge the battery 6.

[0097] In this embodiment, the charging unit 9 can be implemented by combining a rectifier and filter circuit and a constant voltage and constant current charging chip to ensure safe and rapid charging of the battery 6. The rectifier and filter circuit is responsible for converting external AC power to DC power, while the constant voltage and constant current charging chip adjusts the charging voltage and current according to the current state of the battery 6 to provide charging voltage. A power management chip can also be used to achieve fine control of the charging process, further ensuring the safety of the battery 6.

[0098] For details, please refer to Figure 3 and Figure 4 The charging unit 9 is implemented using a USB port and a power management chip U2. The USB port is connected to an external power source, the input terminal of the power management chip U2 is electrically connected to the USB port, and the output terminal of the power management chip U2 is electrically connected to the battery 6. During charging, the power management chip U2 can detect the voltage and current status of the battery 6 in real time and adjust the charging voltage and current according to the detection results to ensure that the battery 6 is charged in a safe and efficient charging state. The battery 6 can be referenced... Figure 4 A battery protection circuit is installed between the positive and negative terminals of battery 6. The battery protection circuit includes functions such as overcharge protection, over-discharge protection, and short circuit protection.

[0099] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A temperature control circuit for a hand warmer, applied to a hand warmer, characterized in that, The temperature control circuit of the hand warmer includes: Heating unit for heating; At least one button unit is used for a first button signal output based on a first user operation and a second button signal output based on a second user operation. The main control unit is electrically connected to the button unit and the heating unit; The main control unit is used to output a first control signal when it receives a first button signal, so as to control the heating unit to heat up to a first working temperature; The main control unit is further configured to control the heating unit to operate at a corresponding driving power based on the number of times the second button signal is received, so that the heating unit heats up to a second operating temperature, wherein the second operating temperature is less than or equal to the first operating temperature.

2. The temperature control circuit of the hand warmer as described in claim 1, characterized in that, The button unit includes: A first button subunit, electrically connected to the main control unit, is used to output a first button signal based on a user's pressing operation; The second button subunit is electrically connected to the main control unit and is used to output a second button signal based on the user's pressing operation; The main control unit is configured with multiple temperature adjustment modes. When the first button signal is received, the main control unit is also used to output the first control signal to control the heating unit to heat up to the first working temperature, or to select the driving power of the corresponding level of the multiple temperature adjustment modes according to the number of times the second button signal is received, so as to control the heating unit to heat up.

3. The temperature control circuit of the hand warmer as described in claim 2, characterized in that, The main control unit is also used to power on or off when it receives the first key signal or the second key signal and the time threshold is reached.

4. The temperature control circuit of the hand warmer as described in claim 1, characterized in that, The temperature control circuit of the hand warmer also includes: The first prompting unit is electrically connected to the main control unit and is used to prompt the user about the operating temperature of the heating unit; the first prompting unit includes an indicator light and / or a display screen.

5. The temperature control circuit of the hand warmer as described in claim 4, characterized in that, The first prompting unit includes five indicator lights electrically connected to the main control unit, which is configured with five temperature adjustment modes. When the main control unit receives the second button signal once, it drives the heating unit to heat according to the first level of the five temperature adjustment modes and activates one indicator light. When the main control unit receives the second button signal twice, it drives the heating unit to heat according to the second level of the five temperature adjustment modes and activates two indicator lights. When the main control unit receives the second button signal three times, it activates the heating unit according to the second level of the five temperature adjustment modes. The third driving power level drives the heating unit to heat up and activates the three indicator lights. The main control unit, when receiving the second button signal four times, drives the heating unit to heat up according to the fourth driving power level of the five-level temperature control mode and activates the four indicator lights. The main control unit, when receiving the second button signal five times, drives the heating unit to heat up according to the fifth driving power level of the five-level temperature control mode and activates the five indicator lights. The driving power values ​​for the first, second, third, fourth, and fifth driving powers are all different.

6. The temperature control circuit of the hand warmer as described in claim 2, characterized in that, The button unit further includes: The third button subunit is used to output a third button signal based on the user's pressing operation; The lighting unit is electrically connected to the main control unit and is used to output a lighting control signal when the main control unit receives the third button signal, so as to control the lighting unit to perform lighting.

7. The temperature control circuit of the hand warmer as described in claim 1, characterized in that, The heating unit includes: At least one switching element and a heating resistor; The switching element is electrically connected to the main control unit, ground, and heating resistor respectively. The main control unit is also used to adjust the duty cycle of the PWM signal to a first preset value when it receives the first button signal, so as to output it to the switching element and control the heating unit to heat up to the first working temperature, or to adjust the duty cycle of the PWM signal successively according to the number of times the second button signal is received, so as to output it to the switching element and control the heating unit to heat up to the second working temperature.

8. The temperature control circuit of the hand warmer as described in claim 1, characterized in that, The temperature control circuit of the hand warmer also includes: Batteries used to output electrical energy from batteries; The second prompting unit is electrically connected to the main control unit and is used to prompt the user about the battery level. The second prompting unit includes an indicator light and / or a display screen. A power detection unit, wherein the sampling end of the power detection unit is electrically connected to the battery, and the output end of the power detection unit is electrically connected to the main control unit, for detecting the voltage of the battery power and then outputting a power detection signal to the main control unit; The main control unit is equipped with a power level indicator mode. The main control unit is also used to control the corresponding indicator light to work in the power level indicator mode according to the received power level detection signal, and / or to control the display screen to work in the power level indicator mode according to the received power level detection signal.

9. The temperature control circuit of the hand warmer as described in claim 8, characterized in that, The temperature control circuit of the hand warmer also includes: A temperature detection unit is provided, wherein the sampling end of the temperature detection unit is electrically connected to the battery, and the output end of the temperature detection unit is electrically connected to the main control unit. The temperature detection unit is used to detect the temperature of the battery and output a battery temperature detection signal so that when the main control unit detects that the battery temperature is too high based on the received battery temperature detection signal, it stops the battery from outputting battery power.

10. The temperature control circuit of the hand warmer as described in claim 8, characterized in that, The temperature control circuit of the hand warmer also includes: A charging unit is provided, wherein the input terminal of the charging unit is connected to an external power source, and the output terminal of the charging unit is electrically connected to the battery. The charging unit is used to convert the voltage of the external power source to output charging energy to charge the battery.

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