A hair dryer switch control circuit

Abstract

This utility model relates to the field of electronic circuit technology and discloses a hair dryer switch control circuit, which includes a first switch module, a second switch module, and a voltage sampling module. The first switch module and the second switch module share a signal line and are connected to the control module of the hair dryer. In the first switch module, the gear selection unit outputs different voltages according to different gears. The control module outputs corresponding control signals by reading the voltage value of the voltage sampling module to realize functions such as standby control, high fan speed control, and low fan speed control. In the second switch module, the control module controls the air temperature level according to the number of times the second switch module is triggered. This utility model allows the first switch module and the second switch module to share a signal line and a ground line, reducing the number of wires. By reducing the space occupied by wires in the handle, and the control module of the hair dryer only needs to identify the signal of the switch circuit through a single I / O port, the I / O port resources of the chip are saved.

Description

Technical Field

[0001] This utility model relates to a hair drying device, and in particular to a hair dryer switch control circuit. Background Technology

[0002] Hair dryers are generally used to dry human hair or animal fur. For ease of operation, the switch (or button) is usually located on the handle of the hair dryer, while the main board is located on the head of the device. Therefore, the switch board and the main board need to be connected by wires to transmit the control signals from the switch (or button). Most existing handheld hair dryers use a "one wire, one setting" wiring method for their speed control circuits. For example, in hair dryers with three speed settings (off, low speed, and high speed), four wires are typically required: one for transmitting the interruption signal of the touch switch (this signal is generally used to control the temperature setting based on the number of touches), one for transmitting the off signal of the toggle switch (this can be omitted in some models where the on / off control and temperature are combined), one for transmitting the low speed signal, one for transmitting the high speed signal, and a common ground wire.

[0003] In some highly intelligent hair dryer products, even more wires may be required. For example, in some hair dryer products that automatically control temperature and wind speed with hands-free sensing, more than four wires may be needed. For instance, in the invention patent application number 202410314705.4, entitled "Hand-sensor controlled high-speed hair dryer and its control method," it is disclosed that the switch S is electrically connected to the main control chip U5 on the motherboard through a 4-pin connector, and the sensing chip circuit 217 is also electrically connected to the main control chip U5 on the motherboard through a 4-pin connector. The two 4-pin connectors require 8 wires to connect to the motherboard. Multiple parallel wires must pass through the inner cavity of the handle with a limited diameter, occupying the installation space of other modules of the hair dryer. Moreover, each signal generally occupies one I / O port of the main control chip, occupying the I / O port resources of the main control chip. When additional functions such as hair care and child lock are required, if the number of pins of the main control chip is exhausted, it is often necessary to use a higher package level MCU or an external I / O expansion chip, which directly increases the cost. Utility Model Content

[0004] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a hair dryer switch control circuit that can reduce the number of wires required between the switch circuit and the hair dryer main board circuit.

[0005] To solve the above technical problems, the present invention adopts the following technical solution:

[0006] A hair dryer switch control circuit includes: a first switch module for controlling the fan speed level, a second switch module for controlling the temperature level, and a voltage sampling module. The first switch module and the second switch module are both electrically connected to the voltage sampling module, and the voltage sampling module is electrically connected to the control module of the hair dryer.

[0007] The first switch module includes a gear selection unit, a first voltage divider unit, and a second voltage divider unit. The first output terminal of the gear selection unit is connected to one end of the first voltage divider unit, and the second output terminal of the gear selection unit is connected to one end of the second voltage divider unit. The other end of the first voltage divider unit is connected to the other end of the second voltage divider unit, one end of the second switch module, the voltage sampling module, and ground. The other end of the second switch module is grounded.

[0008] In the hair dryer switch control circuit, the gear selection unit includes a toggle switch, the first voltage divider unit includes a first resistor, the second voltage divider unit includes a second resistor, pin 1 of the toggle switch is the first output terminal of the gear selection unit, which is connected to pin 5 of the toggle switch and one end of the first resistor, pin 3 of the toggle switch is connected to pin 7 of the toggle switch and the other end of the first switch module, pin 4 of the toggle switch is the second output terminal of the gear selection unit, which is connected to pin 8 of the toggle switch and one end of the second resistor, the other end of the first resistor is connected to the other end of the second resistor, one end of the first switch module, the voltage sampling module and ground, and pins 2 and 6 of the toggle switch are left floating.

[0009] In the hair dryer switch control circuit, the first switch module includes a control switch. One end of the control switch is connected to the voltage sampling module and ground, and the other end of the first switch module is connected to pin 3, pin 7 of the toggle switch and ground.

[0010] In the hair dryer switch control circuit, the control switch is a push-button switch, a tactile switch, or a touch switch.

[0011] In the hair dryer switch control circuit, the resistance value of the first resistor is more than 5 times the resistance value of the second resistor.

[0012] In the hair dryer switch control circuit, the hair dryer includes a main board and a switch board. The voltage sampling module is disposed on the main board, and the first switch module and the second switch module are disposed on the switch board. The main board and the switch board are connected when plugged into a socket.

[0013] In the hair dryer switch control circuit, the socket is a 2-pin socket and the plug is a 2-pin plug.

[0014] In the hair dryer switch control circuit, pin 1 of the socket is connected to pins 3 and 7 of the toggle switch and is also grounded through the first switch module. Pin 2 of the socket is connected to the other end of the first resistor, the other end of the second resistor, the first switch module, and ground. The voltage sampling module is located on the motherboard, and the first and second switch modules are located on the switch board. Pin 1 of the plug is electrically connected to the voltage sampling module, and pin 2 of the plug is grounded.

[0015] In the hair dryer switch control circuit, the voltage sampling module includes a third resistor and a fourth resistor. One end of the third resistor is connected to the power supply terminal, and the other end of the third resistor is connected to pin 1 of the plug and is also connected to an input terminal of the control module through the fourth resistor.

[0016] In the hair dryer switch control circuit, the plug is electrically connected to the main board via wires and ribbon cables.

[0017] Compared to existing technologies, the hair dryer switch control circuit provided by this utility model includes: a first switch module, a second switch module, and a voltage sampling module. The first switch module and the second switch module share a signal line connected to the control module of the hair dryer. In the first switch module, the gear selection unit outputs different voltages according to different gears. The control module outputs corresponding control signals by reading the voltage value from the voltage sampling module to achieve functions such as standby control, high fan speed control, and low fan speed control. In the second switch module, the control module controls the air temperature level according to the number of times the second switch module is triggered. This utility model allows the first switch module and the second switch module to share a single signal line and a single ground line, reducing the number of wires and simplifying the wiring. By reducing the space occupied by the wires in the handle, the handle can be designed to be more compact. Moreover, the control module of the hair dryer only needs to identify the signal of the switch circuit through a single I / O port, saving I / O port resources of the chip. Attached Figure Description

[0018] Figure 1 A schematic diagram of the structure of the hair dryer provided by this utility model.

[0019] Figure 2 The circuit block diagram of the hair dryer provided by this utility model.

[0020] Figure 3 The circuit block diagram of the hair dryer switch control circuit provided by this utility model.

[0021] Explanation of reference numerals in the attached figures

[0022] 1. First switch module; 2. Second switch module; 3. Voltage sampling module; 4. Control module; 11. Gear selection unit; 12. First voltage divider unit; 13. Second voltage divider unit; SW1. Toggle switch; R1. First resistor; R2. Second resistor; K1. Control switch; 10. Switch board; 20. Main board; J1. Socket; J2. Plug; R3. Third resistor; R4. Fourth resistor Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model 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 of the present utility model and are not intended to limit the present utility model.

[0024] The hair dryer switch control circuit provided by this utility model compresses all the functions of the standby, low wind speed, and high wind speed modes of the speed selection unit, as well as the temperature level switching function of the second switch module, into a single signal line for transmission. This significantly reduces the number of wires required between the switch circuit and the hair dryer's main board circuit, and also reduces the space occupied inside the handle. This overcomes the problems of complex wiring, bulky handle, and limited MCU pin resources caused by traditional solutions that require three, four, or more wires.

[0025] Please see Figure 1 , Figure 2 and Figure 3 The hair dryer switch control circuit provided by this utility model includes: a first switch module 1 for controlling the wind speed level, a second switch module 2 for controlling the temperature level, and a voltage sampling module 3. The first switch module 1 and the second switch module 2 are both electrically connected to the voltage sampling module 3. The voltage sampling module 3 is electrically connected to the control module 4 of the hair dryer. That is, the first switch module 1 and the second switch module 2 share a signal line (such as a wire) connected to the voltage sampling module 3. The control module 4 reads the voltage value of the voltage sampling module 3 to identify the control commands of the switch circuit, such as power on, standby, cold air, warm air, hot air, low wind speed, or high wind speed. The control module 4 then controls the corresponding circuit working state, such as the power on / off (or standby) circuit, the heating wire heating circuit, or the motor drive circuit, thereby saving the signal line (such as a wire) for communication between the switch circuit and the main board 20 circuit.

[0026] In specific implementation, the first switch module 1 includes a gear selection unit 11, a first voltage divider unit 12, and a second voltage divider unit 13. The first output terminal of the gear selection unit 11 is connected to one end of the first voltage divider unit 12, and the second output terminal of the gear selection unit 11 is connected to one end of the second voltage divider unit 13. The other end of the first voltage divider unit 12 is connected to the other end of the second voltage divider unit 13, one end of the second switch module 2, the voltage sampling module 3, and ground. The other end of the second switch module 2 is grounded. Alternatively, the other end of the first voltage divider unit 12, the other end of the second voltage divider unit 13, and one end of the second switch module 2 can be understood as being connected to the same voltage node. This voltage node is connected to the voltage sampling module 3 via a signal line. The gear selection unit 11 selects different gears to select the corresponding voltage divider unit connected to the voltage sampling module 3, thereby changing the voltage value of the voltage sampling module 3 for the control module 4 to read, thus realizing motor standby, low wind speed operation, high wind speed operation, etc.

[0027] Please refer to the following: Figure 3 The gear selection unit 11 includes a toggle switch SW1, the first voltage divider unit 12 includes a first resistor R1, the second voltage divider unit 13 includes a second resistor R2, the first pin of the toggle switch SW1 is the first output terminal of the gear selection unit 11, which is connected to the fifth pin of the toggle switch SW1 and one end of the first resistor R1, the third pin of the toggle switch SW1 is connected to the seventh pin of the toggle switch SW1 and the other end of the first switch module 1, the fourth pin of the toggle switch SW1 is the second output terminal of the gear selection unit 11, which is connected to the eighth pin of the toggle switch SW1 and one end of the second resistor R2, the other end of the first resistor R1 is connected to the other end of the second resistor R2, one end of the first switch module 1, the voltage sampling module 3 and ground, that is, the other end of the first resistor R1, the other end of the second resistor R2 and one end of the first switch module 1 are connected to the same voltage node and are connected to the voltage sampling module 3 through a signal line, and the second and sixth pins of the toggle switch SW1 are left floating.

[0028] The toggle switch SW1 can be a miniature surface mount switch of model HX MSS23C02. The top position of the toggle switch SW1 is the high speed position, the middle position is the low speed position, and the bottom position is the standby position. The speed is selected by moving the tap of the toggle switch SW1 to contact the contacts of the three positions. This utility model can generate three different voltages on a single signal line by connecting two voltage divider resistors to the toggle switch SW1, so that the MCU (i.e., control module 4) AD port can identify the standby, low speed, and high speed states. In the end, only one wire is needed to connect to the hair dryer motherboard 20 to transmit signals, plus a common ground wire, for a total of two wires to realize the communication between the switch circuit and the motherboard 20 circuit.

[0029] Furthermore, the resistance value of the first resistor R1 is more than 5 times that of the second resistor R2. For example, the resistance value of the first resistor R1 is 10 times that of the second resistor R2. The two large differences in resistance value allow the voltage sampling module 3 to obtain large differences in the voltage division value, thereby enabling the control module 4 to more accurately identify whether the user's command to the toggle switch SW1 is high speed or low speed, avoiding misjudgment.

[0030] Optionally, the first switch module 1 includes a control switch K1. One end of the control switch K1 is connected to the voltage sampling module 3 and ground, and the other end of the first switch module 1 is connected to pin 3, pin 7 of the toggle switch SW1 and ground. The control module 4 is interrupted by the number of times the control switch K1 is triggered, so that the control module 4 can identify and output corresponding control signals, such as cold air, warm air, hot air or negative ion switch.

[0031] In an optional embodiment, the control switch K1 is a push-button switch, a tactile switch, or a touch switch. This invention can select a tactile switch, and the control module 4 can generate a corresponding number of interrupts by the number of times the tactile switch is pressed, so that the control module 4 can recognize the control commands input by the user.

[0032] In one application embodiment, the hair dryer includes a main board 20 and a switch board 10. The voltage sampling module 3 is disposed on the main board 20, and the first switch module 1 and the second switch module 2 are disposed on the switch board 10. The main board 20 and the switch board 10 are electrically connected when they are plugged into a socket J1 and a plug J2.

[0033] In an optional embodiment, a socket J1 is provided on the switch plate 10, and two wires are soldered on the main board 20. A plug J2 is connected to the end of the wires. After the main board 20 is installed in the head of the hair dryer and the switch plate 10 is installed in the handle, the plug J2 is then plugged into the socket J1 on the switch plate 10. This method is convenient to install and requires fewer plugs J2 and sockets J1, resulting in lower costs.

[0034] Of course, in other embodiments, another socket can be provided on the motherboard 20, and a plug J2 is connected to both ends of the wire. The plug J2 is plugged into the socket J1 on the motherboard 20 and the switch board 10 respectively to realize the transmission of signals between the switch board 10 and the motherboard 20.

[0035] In terms of electrical connection, in addition to wires, this utility model can also use ribbon cables, FPC flexible circuit boards, etc., as long as the communication between the switch board 10 and the motherboard 20 can be realized. This utility model does not limit this.

[0036] Please continue reading. Figure 3The socket J1 is a 2-pin socket and the plug J2 is a 2-pin plug. Compared with the existing ones that require four wires and a 4-pin plug (or connector), the 2-pin plug and socket have lower procurement costs and take up less space in the handle.

[0037] Correspondingly, pin 1 of socket J1 is connected to pins 3 and 7 of toggle switch SW1 and is also grounded through the first switch module 1, i.e., through control switch K1. Pin 2 of socket J1 is connected to the other end of the first resistor R1, the other end of the second resistor R2, one end of control switch K1, and ground. Pin 1 of plug J2 is electrically connected to voltage sampling module 3, and pin 2 of plug J2 is grounded. When plug J2 is plugged into socket J1, the first resistor R1, the second resistor R2, and control switch K1 are all electrically connected to voltage sampling module 3, and pin 2 of socket J1 is connected to pin 1 of plug J2 and grounded. Optionally, plug J2 is soldered to corresponding pads on the motherboard via two wires. One of the two wires serves as a signal line, allowing the control module to read the voltage value from voltage sampling module 3 to identify user commands received by the switch board, and the other serves as a ground wire.

[0038] Please continue reading. Figure 3 The voltage sampling module 3 includes a third resistor R3 and a fourth resistor R4. One end of the third resistor R3 is connected to the power supply terminal, and the other end of the third resistor R3 is connected to pin 1 of the plug J2 and also connected to an input terminal of the control module 4 through the fourth resistor R4. The third resistor R3 is the upper-level resistor, and the fourth resistor R4 is a voltage divider. Combined with the first resistor R1 or the second resistor R2, the voltage sampling module 3 feeds back the corresponding voltage for the control module 4 to read.

[0039] The power supply terminal is a 5V power supply terminal. The control module 4 includes an MCU chip, such as CMS32M5710, LKS32MC038, N32G435, etc. This utility model only requires the MCU chip to provide one AD port (i.e., IO port) to read the voltage divider between the fourth resistor R4 and the switching circuit. Figure 3 The SPEED connector on the left is used to connect to the AD port (i.e., I / O port) of the MCU chip. The resistance of the third resistor R3 is between that of the first resistor R1 and the second resistor R2. The resistance of the second resistor R2 is more than 10 times that of the fourth resistor R4, making the fourth resistor R4 the smallest of the four resistors. The resistance of the fourth resistor R4 can be 1KΩ.

[0040] When power plug J2 is connected to AC power, the fourth resistor R4 is pulled up to a +5V high level. The MCU chip's AD port reads this high-level signal, allowing it to monitor user commands to the switching circuit. When the toggle switch SW1 is switched to the highest position, the first resistor R1 is connected to the voltage acquisition module, causing the voltage drop across the fourth resistor R4 to reach the first voltage value. This first voltage value is read by the MCU chip's AD port, indicating that the MCU chip recognizes the user command as a high-speed signal, thus causing the motor to operate at high speed. When the toggle switch SW1 is switched to the middle position, it is disconnected from ground, and the voltage drop across the fourth resistor R4 reaches the second voltage value. The second voltage value read by the MCU chip is approximately 5V, pulled up by the third resistor R3. This low-speed signal indicates that the MCU chip recognizes the user command as a low-speed signal, thus causing the motor to operate at low speed. When the toggle switch SW1 is turned to the lowest position, the second resistor R2 is connected to the voltage sampling module 3. At this time, the MCU chip reads the voltage value of the fourth resistor R4 as the third voltage value, causing the hair dryer to enter standby (low power) mode. The MCU chip automatically enters low power mode. Optionally, the voltage difference between the first, second, and third voltage values ​​is 1V-4V, which can be achieved by setting the resistance values ​​of the first, second, third, and fourth resistors as needed, allowing the MCU chip to accurately read the voltage value from the voltage sampling module. It should be noted that the correspondence between the first, second, and third voltage values ​​and the corresponding positions of the toggle switch can be stored in the MCU chip. The first, second, and third voltage values ​​are not necessarily sequentially increasing or decreasing. This invention only requires that the three voltage values ​​be different so that the MCU chip's AD port can read the corresponding voltage value and identify the position of the toggle switch SW1.

[0041] This invention also controls the corresponding function by detecting the number of times the control switch K1 is triggered. When the control switch K1 is pressed, i.e., when the control switch K1 is closed and grounded, the AD port of the MCU chip is pulled low, generating an interrupt. At this time, the heating power of the hair dryer's heating wire is set to the first level, so that the air blown out by the hair dryer is warm air with a temperature of 30℃-35℃. When the control switch K1 is pressed again, the AD port of the MCU chip detects that the control switch K1 has been pressed again, so that the heating power of the hair dryer's heating wire is set to the second level, so that the air blown out by the hair dryer is warm air. The system operates on a warm air setting of 40℃-45℃. When control switch K1 is pressed again, the MCU chip's AD port detects that switch K1 has been pressed once more. At this time, the MCU chip sets the heating element's power to the third level, resulting in hot air at a temperature of 51℃-60℃. Pressing control switch K1 again activates the negative ion function, and pressing it again deactivates it. Pressing it again switches to cool air, and the cycle repeats. For quick switching to cool air, the user can press and hold the control switch for more than 2 seconds. Since the hot / cold air switching method is existing technology and not protected by this invention, it will not be described in detail here.

[0042] In summary, this utility model compresses all the functions of the speed selection unit—standby, low wind speed, high wind speed, and temperature setting switching—into a single signal line for transmission. This significantly reduces the number of wires required between the switching circuit and the hair dryer's main board. The reduction in the number of wires also reduces the complexity of wiring, decreases the space occupied inside the handle, and allows for a smaller handle design, thus improving the product's portability and aesthetics.

[0043] The hair dryer's control module can identify the switching circuit signal through only one I / O port, saving the chip's I / O port resources and providing the possibility to add other functions (such as hair care, child lock, etc.). Moreover, the reduction in the number of wires and the simplification of wiring help improve the reliability of the circuit and reduce failures caused by wire connection problems.

[0044] Meanwhile, this utility model only requires a 2-pin plug and a 2-pin socket to connect the switch board and the motherboard. The procurement cost of the 2-pin plug and socket is much lower than that of the 4-pin plug and socket. It also reduces the installation complexity of the plug and socket and lowers the hardware procurement and assembly costs.

[0045] Furthermore, the switching circuit of this invention uses only a few conventional electronic components, resulting in a simple circuit structure, low cost of electronic components, and low maintenance cost.

[0046] It is understood that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of this utility model, and all such substitutions or changes should fall within the protection scope of the appended claims of this utility model.

Claims

1. A hair dryer switch control circuit, characterized in that, include: A first switch module (1) for controlling the wind speed setting, a second switch module (2) for controlling the temperature setting, and a voltage sampling module (3). The first switch module (1) and the second switch module (2) are both electrically connected to the voltage sampling module (3), and the voltage sampling module (3) is electrically connected to the control module (4) of the hair dryer. The first switch module (1) includes a gear selection unit (11), a first voltage divider unit (12) and a second voltage divider unit (13). The first output terminal of the gear selection unit (11) is connected to one end of the first voltage divider unit (12), and the second output terminal of the gear selection unit (11) is connected to one end of the second voltage divider unit (13). The other end of the first voltage divider unit (12) is connected to the other end of the second voltage divider unit (13), one end of the second switch module (2), the voltage sampling module (3) and ground. The other end of the second switch module (2) is grounded.

2. The hair dryer switch control circuit according to claim 1, characterized in that, The gear selection unit (11) includes a gear selector switch (SW1), the first voltage divider unit (12) includes a first resistor (R1), the second voltage divider unit (13) includes a second resistor (R2), the first pin of the gear selector switch (SW1) is the first output terminal of the gear selection unit (11), which is connected to the fifth pin of the gear selector switch (SW1) and one end of the first resistor (R1), the third pin of the gear selector switch (SW1) is connected to the seventh pin of the gear selector switch (SW1) and the other end of the first switch module (1), the fourth pin of the gear selector switch (SW1) is the second output terminal of the gear selection unit (11), which is connected to the eighth pin of the gear selector switch (SW1) and one end of the second resistor (R2), the other end of the first resistor (R1) is connected to the other end of the second resistor (R2), one end of the first switch module (1), the voltage sampling module (3) and ground, and the second and sixth pins of the gear selector switch (SW1) are left floating.

3. The hair dryer switch control circuit according to claim 2, characterized in that, The first switch module (1) includes a control switch (K1), one end of which is connected to the voltage sampling module (3) and ground, and the other end of the first switch module (1) is connected to pin 3, pin 7 of the toggle switch (SW1) and ground.

4. The hair dryer switch control circuit according to claim 3, characterized in that, The control switch (K1) is a push-button switch, a tactile switch, or a touch switch.

5. The hair dryer switch control circuit according to claim 2, characterized in that, The resistance of the first resistor (R1) is more than 5 times the resistance of the second resistor (R2).

6. The hair dryer switch control circuit according to claim 2, characterized in that, The hair dryer includes a main board (20) and a switch board (10) which are electrically connected when plugged into a socket (J1) and a plug (J2).

7. The hair dryer switch control circuit according to claim 6, characterized in that, The socket (J1) is a 2-pin socket, and the plug (J2) is a 2-pin plug.

8. The hair dryer switch control circuit according to claim 6, characterized in that, The first pin of the socket (J1) is connected to the third and seventh pins of the toggle switch (SW1) and is also grounded through the first switch module (1). The second pin of the socket (J1) is connected to the other end of the first resistor (R1), the other end of the second resistor (R2), one end of the first switch module (1), and ground. The voltage sampling module (3) is mounted on the main board (20). The first switch module (1) and the second switch module (2) are mounted on the switch board (10). The first pin of the plug (J2) is electrically connected to the voltage sampling module (3), and the second pin of the plug (J2) is grounded.

9. The hair dryer switch control circuit according to claim 8, characterized in that, The voltage sampling module (3) includes a third resistor (R3) and a fourth resistor (R4). One end of the third resistor (R3) is connected to the power supply terminal, and the other end of the third resistor (R3) is connected to pin 1 of the plug (J2) and is also connected to an input terminal of the control module (4) through the fourth resistor (R4).

10. The hair dryer switch control circuit according to claim 6 or 7, characterized in that, The plug (J2) is electrically connected to the motherboard (20) via wires and ribbon cables.

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