Precise constant temperature device of hair drier and hair drier

Abstract

The constant temperature device comprises an NTC resistor arranged on a heating wire and a circuit board for controlling the NTC resistor, an MCU is arranged on the circuit board to obtain an NTC resistor signal and control the heating power of the heating wire so that the temperature can be constant, and different working modes can be selected through a multi-gear switching module. The temperature control device has the advantages that the NTC fixed on the heating wire is used for collecting the temperature value near the heating wire, the MCU reads the temperature value, then the silicon controlled rectifier is used for adjusting the output of the heating wire, closed-loop control is formed, and the temperature control device is simple in structure, convenient to use and high in practicability. And the temperature is constant.

Description

Technical Field

[0001] The present application relates to the technical field of constant temperature control of hair dryers, and in particular to a precise constant temperature device for a hair dryer and a hair dryer. Background Art

[0002] Hair dryers are a common household appliance, widely used in daily life. Their convenience is widely appreciated, especially in today's fast-paced world. They not only quickly dry wet hair but can also be used for daily massages and other applications. The development of hair dryers has long driven technological advancements in the personal care industry, improving people's quality of life and becoming an indispensable small appliance in modern households. Existing hair dryers typically use a heating wire (or mesh) to generate hot air. Over time, the heating wire gradually heats up, causing the temperature of the hot air to rise continuously. To address this problem, various solutions have emerged on the market. One approach involves using an adjustable temperature control knob, allowing the user to manually adjust the temperature. Another approach involves integrating a temperature sensor into the hair dryer. However, this sensor's frequency of temperature detection is low, typically only a few to a dozen times per second. This results in inaccurate temperature control and can lead to significant temperature fluctuations. Another approach involves combining a temperature sensor with a simple temperature control circuit to achieve relatively stable temperature.

[0003] Among the various methods mentioned above, whether it is manual temperature adjustment or a simple temperature sensor combined with a control circuit, none of them can achieve rapid temperature response and high-precision control during specific use. Especially in physical therapy scenarios with strict temperature requirements, there is still the problem of not being able to maintain a constant temperature. Utility Model Content

[0004] The purpose of this application is to overcome the above technical problems and provide a precise constant temperature device for a hair dryer and a hair dryer

[0005] A precise thermostat for a hair dryer includes an NTC resistor mounted on a heating wire and a circuit board for controlling the NTC resistor. The circuit board includes an MCU, which receives a signal from the NTC resistor and obtains the real-time temperature of the heating wire. Preferably, the MCU controls the heating power of the heating wire based on the real-time temperature value to maintain a constant temperature. Preferably, the device also includes a mirror display screen connected to the circuit board for displaying the real-time temperature value. Preferably, the device also includes the MCU mounted on the circuit board, the MCU having a set temperature range. Preferably, the MCU adjusts the power of the heating wire to maintain the temperature within the set temperature range. Preferably, the circuit board also includes a multi-speed switching module, which provides at least two operating modes. Preferably, the at least two operating modes include a hair-drying mode and a physical therapy mode. Preferably, the set temperature range corresponding to the hair-drying mode is 50°C to 60°C, and the set temperature range corresponding to the physical therapy mode is 40°C to 50°C. Preferably, the NTC resistor is mounted on the heating wire to directly obtain the surface temperature of the heating wire. A hair dryer includes the precise thermostat.

[0006] The beneficial effect of the present invention is that the temperature value near the heating wire is collected by the NTC fixed on the heating wire, the MCU reads the temperature value, and then the output of the heating wire is adjusted by the thyristor to form a closed-loop control so that the temperature is kept constant. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a structural schematic diagram of a thermostat device of a hair dryer according to an embodiment of the utility model.

[0008] Figure 2 This is a schematic diagram of the MCU on a circuit board according to an embodiment of the present invention.

[0009] Figure 3 This is a schematic diagram of a constant temperature control circuit on a circuit board according to an embodiment of the present utility model.

[0010] Figure 4 This is a schematic diagram of an NTC resistor circuit on a circuit board according to an embodiment of the present utility model.

[0011] Figure 5 It is a structural schematic diagram of a hair dryer according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0012] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the present invention. The described embodiments are only possible technical implementations of the present invention and are not all possible implementations. Those skilled in the art can fully combine the embodiments of the present invention to derive other embodiments without creative work, and these embodiments are also within the scope of protection of the present invention.

[0013] The inventors of the present application have discovered that when a hair dryer is used, it uses a heating wire for heating. As time goes by, the heating wire gets hotter and hotter, causing the hot air from the hair dryer to get hotter and hotter, which can cause serious damage to the hair and burn the scalp. In addition, a hair dryer can not only blow hair, but also use hot air to blow the body for physical therapy. The temperature that the body is subjected to requires a constant temperature. Overheating not only fails to achieve a therapeutic effect, but also damages the skin. To this end, the present application mainly adopts the provision of a temperature detection device to achieve rapid temperature detection and control, achieving a multi-purpose constant temperature effect, solving the problem of hair damage caused by temperature fluctuations of the heating wire and skin damage during physical therapy, and achieving a good constant temperature effect. The following is a further detailed description of the present application.

[0014] Example 1

[0015] like Figure 1 As shown, an embodiment of the present application provides a precise thermostat for a hair dryer, comprising an NTC resistor 3 mounted on a heating wire, and a circuit board 1 for controlling the NTC resistor 3. The circuit board also includes an MCU 2, which receives signals from the NTC resistor 3 and determines the real-time temperature of the heating wire 4. The MCU then adjusts the power output of the heating wire via a thyristor 6. This design enables highly precise temperature control, preventing damage from temperature fluctuations.

[0016] Specifically, the NTC resistor 3 includes a sensitive element arranged on the heating wire, which is an NTC resistor in the embodiment of the present utility model. The resistance value of the sensitive element changes with the change of temperature, and sensitive elements of different materials can be selected to adapt to different working environments. For example, commonly used materials include manganese copper, nickel copper alloy or copper nickel chromium alloy. Sensitive elements of different materials can provide more stable resistance change characteristics in different temperature ranges. In addition, the sensitive element can be installed in a variety of ways, such as directly sticking it on the surface of the heating wire, or wrapping it around the heating wire with insulating material to ensure its stable working performance.

[0017] like Figure 2 As shown, the MCU uses the FU6562T / TSSop-28, which is used to obtain the resistance value of the NTC resistor and control the output signal, that is, to control the power output of the heating wire. In this embodiment of the utility model, the MCU obtains the value of the NTC resistor up to 1000 times per second. The powerful computing processing capability is one of the requirements for constant temperature control.

[0018] like Figure 3 As shown, the power input is through P1 and P3, with the N line connected to P3 and the L line connected to P1. P2 and P5 are the heating coil output terminals, with P1 and P5 directly connected. P3 and P2 are connected via a thyristor (SCR) Q1. The SCR is a BT139C / TO-220. Pin 1 of the SCR is connected to P3, and pin 2 to P2. Pin 3 is connected to a SCR coupler (MPCM3063 / SO-4) and then to the MCU's TIM2 terminal via resistor R7. Pin 1 of SCR coupler U1 is connected to pin 2 of the SCR via resistors R3 and R4 to control the SCR. The principle is that SCR coupler U1 receives a control signal from the MCU via TIM2. Based on this control signal, SCR coupler U1 switches pins 1 and 2 on and off, thereby controlling the power of the heating coil.

[0019] like Figure 4 As shown, one end of the NTC resistor J2 is grounded, and the other end is connected to the VDD5 port of the MCU through the resistor R31 for inputting the temperature signal, and is connected to IO_B through the resistors R32 and R33. IO_B is used to connect the indicator light.

[0020] The NTC resistor 3 may also include a wire and a connector connected to the sensitive element, which are used to transmit the temperature signal detected by the sensitive element to the circuit board. The wire is usually made of high-temperature resistant materials, such as Teflon or polytetrafluoroethylene, to prevent insulation damage in a high-temperature environment. The connector is made of high-temperature resistant synthetic resin material to ensure the stability of the connection. The connection between the wire and the connector can be welded or crimped to ensure that the connection is firm and reliable. The circuit board is the core component of the entire device, including the MCU and other related electronic components. The MCU obtains the signal of the NTC resistor 3, calculates the real-time temperature value through a complex algorithm, and adjusts the power of the heating wire accordingly. The MCU can be implemented in various forms such as a microprocessor, a single-chip microcomputer or a dedicated integrated circuit. For example, when a microprocessor is used, real-time processing of the temperature signal can be achieved through programming; if a dedicated integrated circuit is used, specific temperature control functions can be customized according to specific needs. The electronic components in the MCU also include the power management circuit, signal amplification circuit, etc. required by the MCU. Such as Figure 5 As shown, the utility model also relates to a hair dryer 10, in which the circuit board 1, NTC resistor 3 and heating wire 4 in the above embodiment are arranged in the heating barrel of the hair dryer, and an MCU 2 is arranged on the circuit board.

[0021] like Figure 1As shown, the circuit board can also be provided with a display screen 5 for displaying real-time temperature values. For example, the display screen can be an LCD or LED screen, and can intuitively display the current temperature through a graphical interface. The size of the display screen can be selected according to actual needs, typically between two and four inches. The real-time temperature value provided can be set to refresh more than one thousand times per second to ensure accurate temperature display and fast response.

[0022] The circuit board also features a multi-speed switching module, providing at least two operating modes. For example, a blow-drying mode with a set temperature range of 50°C to 60°C and a therapy mode with a set temperature range of 40°C to 50°C is provided. This switching module can be implemented using a mechanical switch or a touch button, allowing the user to easily switch between modes. The multi-speed switching module can also integrate a user interface, such as setting different temperature thresholds via a touchscreen, further enhancing ease of use.

[0023] The NTC resistor 3 is placed at the heating wire to directly measure the temperature of the air passing through it, thereby ensuring accurate temperature detection. Heating wires are typically made of high-resistance alloys, such as nickel-chromium or constantan. The choice of different materials can affect the accuracy of temperature control. To improve the sensitivity of temperature detection, experiments can be conducted with heating wires of varying diameters and lengths to select the optimal size to ensure temperature response speed and control accuracy. Through the above design, the precise thermostat device for the hair dryer of this embodiment achieves high-precision control of the heating wire temperature, improves temperature response speed, and provides a user-friendly interface, making it suitable not only for daily hair drying but also for more sophisticated treatments. The operating principle of this embodiment is as follows: This embodiment provides an efficient and stable temperature control solution. By detecting the temperature changes of the heating wire in real time, it quickly responds and adjusts the power, effectively avoiding potential damage to the user's hair or skin caused by overheating. Furthermore, by providing multiple operating modes, the device can be adapted to different application scenarios to meet the diverse needs of users. Compared to traditional manual adjustment or other simple temperature control solutions, this embodiment greatly improves the accuracy and convenience of temperature control, significantly improving the user experience.

[0024] Example 2

[0025] This embodiment differs from the previous embodiment in that the structural design and installation of the NTC resistor 3 are further optimized. Specifically, the NTC resistor is non-contactly mounted at the end of the heating wire adjacent to the air outlet, within the gap between the mounting bracket and the heating wire, rather than simply in contact with the outside. This design makes temperature detection more direct and accurate, reducing measurement errors caused by external factors. Furthermore, the NTC resistor utilizes a spiral mounting structure to expand its contact area with the heating wire, improving temperature detection accuracy. The spiral structure can also be made of different materials to adapt to different operating environments, such as stainless steel or aluminum alloy. Furthermore, the heating wire can be designed with multiple sections, with one or more NTC resistors installed on each section, forming an independent temperature detection and control system. This approach allows for more precise local temperature control, avoiding the adverse effects of overall temperature fluctuations. The implementation principle and technical effects of this embodiment are as follows: an NTC resistor mounted on the heating wire collects the temperature near the heating wire. The MCU reads this temperature value, and then the thyristor adjusts the output of the heating wire, forming a closed-loop control system to maintain a constant temperature. The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A precise constant temperature device for a hair dryer, characterized in that: The invention comprises an NTC resistor arranged on a heating wire and a circuit board for controlling the NTC resistor. An MCU is arranged on the circuit board. The MCU obtains the signal of the NTC resistor and obtains the real-time temperature value of the heating wire. The MCU adjusts the power output of the heating wire through a thyristor.

2. The precise constant temperature device for a hair dryer according to claim 1, characterized in that: The MCU controls the heating power of the heating wire according to the real-time temperature value to keep the temperature constant. The heating wire is fixed on a heating wire fixing frame. The NTC resistor is non-contactly arranged at the end of the heating wire adjacent to the air outlet, in the gap between the fixing frames, and in the gap between the heating wire and the heating wire bracket.

3. The precise constant temperature device for a hair dryer according to claim 1, characterized in that: It also includes a mirror display screen connected to the circuit board, for displaying the real-time temperature value.

4. The precise constant temperature device for a hair dryer according to claim 1, characterized in that: The device also includes an MCU arranged on the circuit board, and the MCU has a set temperature range.

5. The precise constant temperature device for a hair dryer according to claim 4, characterized in that: The MCU adjusts the power of the heating wire to keep the temperature within the set temperature range.

6. The precise constant temperature device for a hair dryer according to claim 1, characterized in that: The circuit board is further provided with a multi-speed switching module, and the multi-speed switching module provides at least two working modes.

7. The precise constant temperature device for a hair dryer according to claim 6, characterized in that: The at least two working modes include a blowing mode and a physical therapy mode.

8. The precise constant temperature device for a hair dryer according to claim 7, characterized in that: The setting temperature range corresponding to the blowing mode is 50°C to 60°C, and the setting temperature range corresponding to the physiotherapy mode is 40°C to 50°C.

9. The precise constant temperature device for a hair dryer according to claim 1, characterized in that: The NTC resistor is arranged on the heating wire to directly obtain the surface temperature of the heating wire.

10. A hair dryer, characterized in that: The invention comprises the precise constant temperature device according to claim 1.

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