Constant temperature control method for hair drier

Abstract

The invention relates to the field of blowers, in particular to a constant temperature control method for a blower, which comprises the following steps: driving a motor to work at a motor constant voltage set value and driving a heating wire to work at an initial power P1 according to an initial state after starting up, so as to ensure that the blower can work stably; whether the blower is in a working state or an abnormal air outlet state is judged according to the linear distance d between the air outlet of the blower and the blown position, in the working state, the required power P is obtained in real time with the linear distance d between the air outlet of the blower and the blown position as the reference, and the required duty ratio D of the heating wire is obtained according to the required power P; the temperature of the heating wire is further controlled, so that the air temperature of the air outlet is controlled, it is ensured that the blown position can feel the constant temperature in the blowing states at different distances, and the use experience is improved.

Description

Technical Field

[0001] This invention relates to the field of hair dryers, and more specifically to a method for constant temperature control in hair dryers. Background Technology

[0002] As a daily hair care appliance, the core function of a hair dryer is to use a motor-driven fan to generate airflow, which, combined with a heating element, quickly evaporates moisture from the hair to achieve the purpose of drying. Modern hair dryers have gone beyond basic functions, incorporating hair care technology and user-friendly design, becoming tools that combine efficiency and healthy hair care.

[0003] Traditional hair dryers rely on high temperatures to accelerate moisture evaporation, but prolonged exposure to high temperatures can damage the hair cuticle, causing the hair cuticles to lift, resulting in dull, brittle hair. Modern hair dryers have solved this problem through technological innovation. For example, they use high-speed digital motors combined with optimized airflow designs to generate a powerful airflow that reaches directly to the hair roots, significantly shortening drying time and reducing heat damage. Some high-end models also feature intelligent temperature control systems that monitor the outlet temperature in real time using built-in sensors, making dozens of adjustments per second to ensure the temperature remains stable within a suitable range and prevent localized overheating.

[0004] However, most thermostatic hair dryers aim to keep the temperature of the air outlet constant. But the distance between the object and the air outlet also affects the perceived temperature of the air. Conventional thermostatic control methods will cause different blowing postures to change the blowing distance, resulting in inconsistent air temperature and a poor user experience. Summary of the Invention

[0005] The purpose of this invention is to provide a constant temperature control method for a hair dryer, which aims to improve the problem that conventional constant temperature control methods cannot ensure that the temperature of the air blown on different positions is the same.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for constant temperature control of a hair dryer includes the following steps:

[0008] S1. Power on;

[0009] S2. Drive the motor to work with the constant pressure set value of the motor and drive the heating wire to work with the initial power P1;

[0010] S3. The ultrasonic module obtains the straight-line distance d between the air outlet of the hair dryer and the position being blown, and determines whether the hair dryer is within the working distance. If yes, proceed to step S04; otherwise, return to step S02.

[0011] S4. Set the target temperature Tair(d). The sensor acquires the ambient temperature Tenv of the hair dryer, the air density ρ of the environment where the hair dryer is located, and the specific heat capacity of air at constant pressure c.p ;

[0012] S5. Calculate the required power P, which is the product of the theoretical heating power required to heat the airflow Q from the ambient temperature Tenv to the target temperature Tair(d) and the compensation factor, wherein the compensation factor is an exponential decay that occurs with distance d.

[0013] S6. Calculate the duty cycle D applied at the current battery voltage VBAT to deliver the required power P to the heating wire;

[0014] S7. The internal control system of the blower adjusts the air temperature in real time according to the demand duty cycle D.

[0015] Furthermore, it also includes steps

[0016] S11. Set the motor constant pressure setting value and the motor adjustment deceleration value;

[0017] S12. Drive the motor to work at 10% of the initial duty cycle corresponding to the constant pressure setting value of the motor;

[0018] S13. Obtain the voltage value at both ends of the motor and determine whether the voltage value at both ends of the motor is less than or equal to the difference between the constant voltage setting value of the motor and the motor adjustment deceleration value. If yes, proceed to step S14; otherwise, proceed to step S15.

[0019] S14. Increase the voltage across the motor terminals;

[0020] S15. Determine whether the voltage value at both ends of the motor is greater than the difference between the constant voltage setting value of the motor and the motor adjustment deceleration value, and less than the constant voltage setting value of the motor. If so, proceed to step S16; otherwise, proceed to step S14.

[0021] S16. Increase the voltage across the motor terminals;

[0022] S17. Determine whether the voltage value at both ends of the motor is equal to the constant voltage setting value of the motor. If yes, proceed to step S2; otherwise, proceed to step S16.

[0023] Furthermore, the voltage boost rate in step S15 is greater than the boost rate in step S16.

[0024] Furthermore, in steps S12-S17, the voltage boost time at both ends of the motor is less than 60 seconds.

[0025] Furthermore, step S5 satisfies the following formula:

[0026] P = ρ·Q·c p ·[Tair(d)-Tenv]·e kd ,

[0027] k is the attenuation coefficient.

[0028] Furthermore, step S6 satisfies the following formula:

[0029] D = (P·R) / (VBAT) 2 ,

[0030] R is the internal resistance of the heating wire, and VBAT is the current battery voltage.

[0031] Furthermore, the working distance is 0-20cm.

[0032] Furthermore, it includes a battery sampling module, which includes resistors R1, R3, and R4, and capacitor C2;

[0033] One end of resistor R1 is electrically connected to the positive terminal of the battery, the other end of resistor R1 is electrically connected to one end of resistor R3 and one end of resistor R4, and the other end of resistor R3 is electrically connected to one end of capacitor C2, and serves as the output terminal to output VBAT.

[0034] The other end of resistor R4 and the other end of capacitor C2 are both grounded.

[0035] Furthermore, the ultrasonic module includes an interface CN1, a resistor R2, and a capacitor C1;

[0036] The interface CN1 is electrically connected to an external ultrasonic transceiver, and an external +5V voltage is input to pin 3 of the interface CN1; pin 2 of the interface CN1 is electrically connected to one end of resistor R2 and one end of capacitor C1, and the other end of resistor R2 serves as the output terminal to output the straight-line distance d between the air outlet of the hair dryer and the position being blown.

[0037] Pin 1 of interface CN1 and the other end of capacitor C1 are both grounded.

[0038] Furthermore, it also includes a heating wire control module, which includes a first interface H+, a second interface H-, MOSFETs Q2 and Q3, and resistors R9 and R12;

[0039] The first interface H+ and the second interface H- are connected to the two ends of the heating wire. The first interface H+ is electrically connected to the positive terminal of the battery. The second interface H- is electrically connected to the drain of MOSFET Q2 and the drain of MOSFET Q3. The gates of MOSFET Q2 and MOSFET Q3 are electrically connected to one end of resistor R9 and one end of resistor R12. The other end of resistor R9 serves as a control port and is electrically connected to the output terminal of the internal control system of the hair dryer.

[0040] The source of MOS transistor Q2, the source of MOS transistor Q3, and the other end of resistor R12 are all grounded.

[0041] Furthermore, it also includes a motor control module, which includes a third interface M+, a fourth interface M-, a MOSFET Q1, a diode D1, capacitors C3, C4, and C5, and resistors R5, R6, R7, R8, R10, R11, R13, and R14.

[0042] The third interface M+ and the fourth interface M- are electrically connected to the positive and negative terminals of the motor, respectively. The third interface M+ is electrically connected to the positive terminal of the battery, the negative terminal of diode D1, one end of capacitor C3, and one end of resistor R5. The fourth interface M- is electrically connected to the positive terminal of diode D1, the other end of capacitor C3, and the drain of MOSFET Q1. The gate of MOSFET Q1 is electrically connected to one end of resistor R6 and one end of resistor R8. The other end of resistor R6 serves as a control port and is electrically connected to the output terminal of the internal control system of the hair dryer.

[0043] The source of the MOS transistor Q1 is electrically connected to one end of resistor R10, one end of resistor R14, one end of resistor R13 and the other end of resistor R8. The other end of resistor R10 is electrically connected to one end of capacitor C5 and serves as the output terminal to output the current value at both ends of the motor.

[0044] The other end of resistor R5 is electrically connected to one end of resistor R7 and one end of resistor R11. The other end of resistor R7 is electrically connected to one end of capacitor C4 and serves as the output terminal to output the voltage value at both ends of the motor.

[0045] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0046] In the initial state after power-on, the motor is driven by a constant pressure setting and the heating element is driven by an initial power P1 to ensure stable operation of the hair dryer. The straight-line distance d between the hair dryer's outlet and the blown area determines whether the hair dryer is in a working state or an abnormal airflow state. In the working state, the required power P is obtained in real time based on the straight-line distance d between the hair dryer's outlet and the blown area. The required duty cycle D of the heating element is obtained from the required power P, thereby controlling the temperature of the heating element and thus controlling the air temperature at the outlet. This ensures that the blown area feels a constant temperature at different distances, improving the user experience. Attached Figure Description

[0047] Figure 1 This is a flowchart of the constant temperature control method for the hair dryer described in this invention;

[0048] Figure 2 This is a partial flowchart of the constant temperature control method for the hair dryer described in this invention;

[0049] Figure 3 This is a circuit diagram of the battery sampling module in the constant temperature control method for the hair dryer described in this invention;

[0050] Figure 4 This is a circuit diagram of the ultrasonic module of the hair dryer constant temperature control method described in this invention;

[0051] Figure 5 This is a circuit diagram of the heating wire control module in the constant temperature control method for the hair dryer described in this invention.

[0052] Figure 6 This is a circuit diagram of the motor control module of the hair dryer constant temperature control method described in this invention. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0054] Additionally, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are all based on the orientation or positional relationship shown in the accompanying drawings. They are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element of the present invention must have a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0055] When an element is referred to as being "fixed to," "set on," or "contained on" another element, it can be directly on or indirectly on that other element. When an element is referred to as being "connected to," it can be directly connected to or indirectly connected to that other element.

[0056] Unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0057] Example

[0058] Please refer to Figure 1-6 As shown, this embodiment provides a method for constant temperature control of a hair dryer. Please refer to [the provided text]. Figure 1 As shown, the following steps are included:

[0059] S1. Power on the device;

[0060] S2. Drive the motor to work at a constant voltage set value of the motor, and drive the heating wire to work at an initial power P1;

[0061] S3. The ultrasonic module obtains the straight-line distance d between the air outlet of the hair dryer and the position to be blown, and determines whether the hair dryer is within the working distance. If so, proceed to step S04; if not, return to step S02. In this embodiment, the working distance is 0 - 20 cm, that is, 0 < d < 20 cm. When the straight-line distance d between the air outlet of the hair dryer and the position to be blown is within 0 to 20 centimeters, it is considered a working state, and when it exceeds 20 centimeters, it is considered a non-working state. Similarly, other ranges can also be set.

[0062] S4. Set the target temperature Tair(d), and the sensor obtains the working environment temperature Tenv of the hair dryer, the air density ρ and the specific heat capacity at constant pressure c of the environment where the hair dryer is located p ;

[0063] S5. Calculate the required power P. The required power P is the product of the theoretical heating power for heating the air flow Q from the environment temperature Tenv to the target temperature Tair(d) and the compensation factor. The compensation factor is an exponential decay with respect to the distance d. Specifically, it satisfies the following formula,

[0064] P = ρ·Q·c p ·[Tair(d) - Tenv]·e kd ,

[0065] where k is the attenuation coefficient;

[0066] S6. Calculate the duty cycle D applied to deliver the required power P to the heating wire under the current battery voltage VBAT; specifically, it satisfies the following formula,

[0067] D = (P·R) / (VBAT) 2 ,

[0068] where R is the internal resistance of the heating wire and VBAT is the current battery voltage;

[0069] S7. The internal control system of the hair dryer adjusts the air temperature in real time with the required duty cycle D.

[0070] In the initial state after power-on, the motor is driven by a constant pressure setting and the heating element is driven by an initial power P1 to ensure stable operation of the hair dryer. The straight-line distance d between the hair dryer's outlet and the blown area determines whether the hair dryer is in a working state or an abnormal airflow state. In the working state, the required power P is obtained in real time based on the straight-line distance d between the hair dryer's outlet and the blown area. The required duty cycle D of the heating element is obtained from the required power P, thereby controlling the temperature of the heating element and controlling the air temperature at the outlet. This ensures that the blown area feels a constant temperature at different distances, improving the user experience.

[0071] Please refer to Figure 2 As shown, the hair dryer temperature control method further includes the following steps:

[0072] S11. Set the motor constant pressure setting value and the motor adjustment deceleration value;

[0073] S12. Drive the motor to work at 10% of the initial duty cycle corresponding to the constant pressure setting value of the motor;

[0074] S13. Obtain the voltage value at both ends of the motor and determine whether the voltage value at both ends of the motor is less than or equal to the difference between the constant voltage setting value of the motor and the motor adjustment deceleration value. If yes, proceed to step S14; otherwise, proceed to step S15.

[0075] S14. Increase the voltage across the motor terminals;

[0076] S15. Determine whether the voltage value at both ends of the motor is greater than the difference between the constant voltage setting value of the motor and the motor adjustment deceleration value, and less than the constant voltage setting value of the motor. If so, proceed to step S16; otherwise, proceed to step S14.

[0077] S16. Increase the voltage across the motor terminals;

[0078] S17. Determine whether the voltage value at both ends of the motor is equal to the constant voltage setting value of the motor. If yes, proceed to step S2; otherwise, proceed to step S16.

[0079] Furthermore, the voltage boost rate in step S15 is greater than the boost rate in step S16.

[0080] The motor is driven with a low duty cycle in the initial state, and the motor adjustment deceleration value is set. The voltage across the motor is controlled to rapidly increase based on the difference between the motor constant voltage set value and the motor adjustment deceleration value. The wind speed also rapidly increases accordingly. When the voltage value across the motor reaches the difference between the motor constant voltage set value and the motor adjustment deceleration value, it is increased at a low speed to improve the control accuracy of the wind speed and avoid the wind speed from fluctuating due to a decrease in speed after the motor wind speed becomes too fast. Further, in steps S12 - S17, the voltage boost time across the motor is less than 60 s, which effectively ensures that the voltage across the motor can rapidly reach the motor constant voltage set value and performs constant voltage control on the motor. Similarly, a smaller or larger boost time can also be set.

[0081] In another embodiment, the hair dryer constant temperature control method further includes steps

[0082] S31. When 0 < d < 18 cm, step S4 is performed. When 18 ≤ d < 22 cm, the heating wire is driven to work at the initial power P1, and step S32 is performed. When 22 ≤ d < 26 cm, the heating wire is driven to work at 80% P1, and step S32 is performed. When 26 ≤ d < 35 cm, the heating wire is driven to work at 60% P1, and step S32 is performed. When d > 35 cm, the heating wire is driven to work at 10% P1, and step S32 is performed;

[0083] S32. After the holding time reaches 30 S, it is judged whether the straight - line distance d between the hair dryer air outlet and the position being blown is within the working distance. If so, step S4 is performed. If not, the driving power of the heating wire is reduced by 5%, and the timing is restarted until the hair dryer is shut down.

[0084] The working temperature of the heating wire is controlled in a stepped manner to avoid the temperature of the heating wire from being too high or too low, which affects the lifespan of the heating wire. And in the case of being in a non - working distance for a long time, the energy consumption is reduced until it is automatically shut down, avoiding the hair dryer from malfunctioning for a long time and causing a fire hazard.

[0085] Further, the control system in the hair dryer records each long - term working distance and adapts the distance limit in step S31 according to the habitual working distance to avoid mis - control and affect the use of the hair dryer.

[0086] Please refer to Figure 3 As shown in, specifically, the hair dryer constant temperature control method includes a battery sampling module. The battery sampling module includes resistor R1, resistor R3, resistor R4, and capacitor C2.

[0087] One end of resistor R1 is electrically connected to the positive terminal of the battery. The other end of resistor R1 is electrically connected to one end of resistor R3 and one end of resistor R4. The other end of resistor R3 is electrically connected to one end of capacitor C2, and serves as the output terminal for VBAT. The other ends of resistor R4 and capacitor C2 are both grounded.

[0088] Please refer to Figure 4 As shown, specifically, the ultrasonic module for the constant temperature control method of the hair dryer includes an interface CN1, a resistor R2, and a capacitor C1. Interface CN1 is electrically connected to an external ultrasonic transceiver, with an external +5V voltage input to pin 3 of interface CN1. Pin 2 of interface CN1 is electrically connected to one end of resistor R2 and one end of capacitor C1. The other end of resistor R2 serves as the output terminal, outputting the linear distance d between the hair dryer's air outlet and the position being blown. Pin 1 of interface CN1 and the other end of capacitor C1 are both grounded. Resistor R2 and capacitor C1 form an RC filter circuit to filter out noise and ensure stable transmission of distance information.

[0089] Please refer to Figure 5 As shown, specifically, the constant temperature control method for the hair dryer also includes a heating wire control module. This module includes a first interface H+, a second interface H-, MOSFETs Q2 and Q3, and resistors R9 and R12. The first interface H+ and the second interface H- are connected to the two ends of the heating wire. The first interface H+ is electrically connected to the positive terminal of the battery, and the second interface H- is electrically connected to the drains of MOSFETs Q2 and Q3. The gates of MOSFETs Q2 and Q3 are both electrically connected to one end of resistor R9 and one end of resistor R12. The other end of resistor R9 serves as a control port and is electrically connected to the output terminal of the hair dryer's internal control system. The sources of MOSFETs Q2 and Q3, and the other end of resistor R12 are all grounded.

[0090] The PWM control signal is connected to the gates of MOSFETs Q2 and Q3 through a current-limiting resistor R9. When the PWM control signal is high, voltage is applied to the gates of MOSFETs Q2 and Q3, putting them in the on state (low resistance), and the heating wire is energized. When the PWM control signal is low, the gate voltages of MOSFETs Q2 and Q3 are pulled low or released, putting them in the off state (high resistance), cutting off the heating wire current and stopping heating. By changing the duty cycle of the PWM control signal, i.e., the proportion of the high-level time to the entire cycle, the proportion of the heating wire's energized time within a cycle can be precisely controlled, thereby achieving continuous and smooth adjustment of its average heating power. A larger duty cycle results in higher average power and higher temperature; a smaller duty cycle results in lower average power and lower temperature. This allows for high-precision, wide-range stepless adjustment of the heating wire with a fast response speed.

[0091] Please refer to Figure 6 As shown, specifically, the constant temperature control method for the hair dryer also includes a motor control module, which includes a third interface M+, a fourth interface M-, a MOSFET Q1, a diode D1, capacitors C3, C4, and C5, and resistors R5, R6, R7, R8, R10, R11, R13, and R14.

[0092] The third interface M+ and the fourth interface M- are electrically connected to the positive and negative terminals of the motor, respectively. The third interface M+ is electrically connected to the positive terminal of the battery, the negative terminal of diode D1, one end of capacitor C3, and one end of resistor R5. The fourth interface M- is electrically connected to the positive terminal of diode D1, the other end of capacitor C3, and the drain of MOSFET Q1. The gate of MOSFET Q1 is electrically connected to one end of resistor R6 and one end of resistor R8. The other end of resistor R6 serves as a control port and is electrically connected to the output terminal of the internal control system of the hair dryer.

[0093] The source of MOSFET Q1 is electrically connected to one end of resistor R10, one end of resistor R14, one end of resistor R13, and the other end of resistor R8. The other end of resistor R10 is electrically connected to one end of capacitor C5 and serves as the output terminal to output the current value at both ends of the motor.

[0094] The other end of resistor R5 is electrically connected to one end of resistor R7 and one end of resistor R11. The other end of resistor R7 is electrically connected to one end of capacitor C4, and serves as the output terminal to output the voltage value across the motor.

[0095] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for constant temperature control of a hair dryer, characterized in that, Includes the following steps: S1. Power on; S2. Drive the motor to work with the constant pressure set value of the motor and drive the heating wire to work with the initial power P1; S3. The ultrasonic module obtains the straight-line distance d between the air outlet of the hair dryer and the position being blown, and determines whether the hair dryer is within the working distance. If yes, proceed to step S04; otherwise, return to step S02. S4. Set the target temperature Tair(d). The sensor acquires the ambient temperature Tenv of the hair dryer, the air density ρ of the environment where the hair dryer is located, and the specific heat capacity of air at constant pressure c. p ; S5. Calculate the required power P, which is the product of the theoretical heating power required to heat the airflow Q from the ambient temperature Tenv to the target temperature Tair(d) and the compensation factor, wherein the compensation factor is an exponential decay that occurs with distance d. S6. Calculate the duty cycle D applied at the current battery voltage VBAT to deliver the required power P to the heating wire; S7. The internal control system of the blower adjusts the air temperature in real time according to the demand duty cycle D.

2. The constant temperature control method for a hair dryer according to claim 1, characterized in that: It also includes steps S11. Set the motor constant pressure setting value and the motor adjustment deceleration value; S12. Drive the motor to work at 10% of the initial duty cycle corresponding to the constant pressure setting value of the motor; S13. Obtain the voltage value at both ends of the motor and determine whether the voltage value at both ends of the motor is less than or equal to the difference between the constant voltage setting value of the motor and the motor adjustment deceleration value. If yes, proceed to step S14; otherwise, proceed to step S15. S14. Increase the voltage across the motor terminals; S15. Determine whether the voltage value at both ends of the motor is greater than the difference between the constant voltage setting value of the motor and the motor adjustment deceleration value, and less than the constant voltage setting value of the motor. If so, proceed to step S16; otherwise, proceed to step S14. S16. Increase the voltage across the motor terminals; S17. Determine whether the voltage value at both ends of the motor is equal to the constant voltage setting value of the motor. If yes, proceed to step S2; otherwise, proceed to step S16. Furthermore, the voltage boost rate in step S15 is greater than the boost rate in step S16.

3. The constant temperature control method for a hair dryer according to claim 2, characterized in that: In steps S12-S17, the voltage boost time at both ends of the motor is less than 60 seconds.

4. The constant temperature control method for a hair dryer according to claim 1, characterized in that: Step S5 satisfies the following formula. P=ρ·Q·c p ·[Tair(d)-Tenv]·e kd , k is the attenuation coefficient.

5. The constant temperature control method for a hair dryer according to claim 1, characterized in that: Step S6 satisfies the following formula. D=(P·R) / (VBAT) 2 , R is the internal resistance of the heating wire, and VBAT is the current battery voltage.

6. The constant temperature control method for a hair dryer according to claim 1, characterized in that: The working distance is 0-20cm.

7. The constant temperature control method for a hair dryer according to claim 1, characterized in that: It includes a battery sampling module, which includes resistors R1, R3, and R4, and capacitor C2; One end of resistor R1 is electrically connected to the positive terminal of the battery, the other end of resistor R1 is electrically connected to one end of resistor R3 and one end of resistor R4, and the other end of resistor R3 is electrically connected to one end of capacitor C2, and serves as the output terminal to output VBAT. The other end of resistor R4 and the other end of capacitor C2 are both grounded.

8. The constant temperature control method for a hair dryer according to claim 1, characterized in that: The ultrasonic module includes an interface CN1, a resistor R2, and a capacitor C1. The interface CN1 is electrically connected to an external ultrasonic transceiver, and an external +5V voltage is input to pin 3 of the interface CN1; pin 2 of the interface CN1 is electrically connected to one end of resistor R2 and one end of capacitor C1, and the other end of resistor R2 serves as the output terminal to output the straight-line distance d between the air outlet of the hair dryer and the position being blown. Pin 1 of interface CN1 and the other end of capacitor C1 are both grounded.

9. The constant temperature control method for a hair dryer according to claim 1, characterized in that: It also includes a heating wire control module, which includes a first interface H+, a second interface H-, MOSFETs Q2 and Q3, and resistors R9 and R12. The first interface H+ and the second interface H- are connected to the two ends of the heating wire. The first interface H+ is electrically connected to the positive terminal of the battery. The second interface H- is electrically connected to the drain of MOSFET Q2 and the drain of MOSFET Q3. The gates of MOSFET Q2 and MOSFET Q3 are electrically connected to one end of resistor R9 and one end of resistor R12. The other end of resistor R9 serves as a control port and is electrically connected to the output terminal of the internal control system of the hair dryer. The source of MOS transistor Q2, the source of MOS transistor Q3, and the other end of resistor R12 are all grounded.

10. The constant temperature control method for a hair dryer according to claim 1, characterized in that: It also includes a motor control module, which includes a third interface M+, a fourth interface M-, a MOSFET Q1, a diode D1, capacitors C3, C4, and C5, and resistors R5, R6, R7, R8, R10, R11, R13, and R14. The third interface M+ and the fourth interface M- are electrically connected to the positive and negative terminals of the motor, respectively. The third interface M+ is electrically connected to the positive terminal of the battery, the negative terminal of diode D1, one end of capacitor C3, and one end of resistor R5. The fourth interface M- is electrically connected to the positive terminal of diode D1, the other end of capacitor C3, and the drain of MOSFET Q1. The gate of MOSFET Q1 is electrically connected to one end of resistor R6 and one end of resistor R8. The other end of resistor R6 serves as a control port and is electrically connected to the output terminal of the internal control system of the hair dryer. The source of the MOS transistor Q1 is electrically connected to one end of resistor R10, one end of resistor R14, one end of resistor R13 and the other end of resistor R8. The other end of resistor R10 is electrically connected to one end of capacitor C5 and serves as the output terminal to output the current value at both ends of the motor. The other end of resistor R5 is electrically connected to one end of resistor R7 and one end of resistor R11. The other end of resistor R7 is electrically connected to one end of capacitor C4 and serves as the output terminal to output the voltage value at both ends of the motor.

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