Fan speed regulating device

Abstract

The invention discloses a fan speed regulation device. The fan speed regulation device comprises a voltage conversion circuit, a rotating speed control circuit, a sampling circuit and an input regulation end, the voltage conversion circuit is electrically connected with the rotating speed control circuit; the rotating speed control circuit is electrically connected with the sampling circuit, the input adjusting end and the controlled fan. Wherein the voltage conversion circuit is used for converting an external input voltage into a first preset voltage and a second preset voltage; the input adjusting end is used for receiving external input and generating a rotating speed adjusting instruction; the rotating speed control circuit is used for responding to the rotating speed adjusting instruction and generating rotating speed adjusting voltage and rotating speed adjusting current; the sampling circuit is used for collecting the rotating speed adjusting voltage and the rotating speed adjusting current output by the rotating speed control circuit. Different rotating speed adjusting instructions are generated through the input adjusting end, so that the rotating speed control circuit can generate different voltages and currents to carry out precise speed adjusting control on the fan.

Description

Technical Field

[0001] The present application relates to the technical field of fan speed regulation, and more specifically, to a fan speed regulation device. Background Art

[0002] Fans mainly use motors to drive the impeller to achieve ventilation and air blowing. At present, fans are used more and more in daily life and industrial production. Some production processes need to be carried out under certain wind pressure and air volume to achieve the expected effect. Fan equipment has been widely used in dust removal, ventilation, and air blowing.

[0003] In the prior art, common speed control interface circuits are generally voltage-adjusting speed control interface circuits and duty-cycle-adjusting speed control interface circuits. The microcontroller unit inside the fan adjusts the output of the fan speed by detecting changes in the duty cycle or level.

[0004] However, the current fan speed control devices have a low level of intelligence, and the structures of the fan speed control devices are relatively complex, and the requirements for operators are also high. Many operators find it difficult to accurately control the fan speed control devices to adjust the fan speed to the required speed. Summary of the invention

[0005] In response to at least one defect or improvement need in the prior art, the present invention provides a fan speed control device, which is used to solve the problem that the fan speed control device in the prior art has a low intelligence level and a relatively complex structure, making it inconvenient for operators to use and difficult to accurately control the speed of the fan.

[0006] To achieve the above-mentioned object, according to a first aspect of the present invention, a fan speed regulating device is provided, comprising: a voltage conversion circuit, a speed control circuit, a sampling circuit and an input regulating terminal; the voltage conversion circuit is electrically connected to the speed control circuit; the speed control circuit is electrically connected to the sampling circuit, the input regulating terminal and the controlled fan respectively;

[0007] Wherein, the voltage conversion circuit is used to convert the external input voltage into a first preset voltage and a second preset voltage;

[0008] The input adjustment terminal is used to receive external input and generate a speed adjustment command;

[0009] The speed control circuit is used to respond to the speed adjustment instruction and generate the speed adjustment voltage and the speed adjustment current;

[0010] The sampling circuit is used to collect the speed regulating voltage and speed regulating current output by the speed control circuit.

[0011] In a possible implementation, the speed control circuit further includes: a control chip U3 and a chopper buck circuit; the control chip U3 and the chopper buck circuit are electrically connected;

[0012] Among them, the control chip U3 is used to send a control signal according to the speed adjustment instruction;

[0013] The chopper step-down circuit is used to convert the external input voltage into the target speed voltage according to the control signal.

[0014] In a possible implementation, a serial port transceiver circuit is further included, which is electrically connected to the speed control circuit; the serial port transceiver circuit is used to transmit the speed adjustment voltage and the speed adjustment current.

[0015] In a possible implementation, it also includes a display screen; the display screen is electrically connected to the serial port transceiver circuit; the display screen is used to display the working status of the controlled fan according to the speed adjustment voltage and the speed adjustment current.

[0016] In a possible implementation, the voltage conversion circuit includes: voltage conversion chips U1 and U2; capacitors C1, C2, C3, C4, C5, C6, C7, and C8;

[0017] The first pin of the voltage conversion chip U2 is connected to the external input voltage, and the third pin of the voltage conversion chip U2 is respectively connected to the first pin and the third pin of the voltage conversion chip U1; the second pin of the voltage conversion chip U2 is connected to the second pin of the voltage conversion chip U1; the capacitor C1 is connected in parallel to the first pin and the second pin of the voltage conversion chip U2; the capacitor C2 is connected in parallel to the first pin and the second pin of the voltage conversion chip U2; the capacitors C3, C4, C5, and C6 are respectively connected to the third pin and the second pin of the voltage conversion chip U2; the capacitors C7 and C8 are respectively connected to the fifth pin and the second pin of the voltage conversion chip U1.

[0018] In a possible implementation, the serial port transceiver circuit includes: a chip U4, capacitors C9, C10, C11, C14, and C15;

[0019] One end of capacitor C9 is grounded, and the other end of capacitor C9 is connected to the sixteenth pin of chip U4; the two ends of capacitor C10 are connected in parallel to the second pin and the sixteenth pin of chip U4; the two ends of capacitor C11 are connected in parallel to the first pin and the third pin of chip U4; the two ends of capacitor C14 are connected in parallel to the fourth pin and the fifth pin of chip U4; one end of capacitor C15 is grounded, and the other end of capacitor C15 is connected to the sixth pin of chip U4.

[0020] In a possible implementation, the chopper step-down circuit includes: resistors R2, R6, R8, R9, R10, R11, R12, R13, R14; diode D1, transistors Q1, Q2; capacitors C12, C13; inductor L1; interface TP2;

[0021] One end of the resistor R9 is connected to the control chip U3, the other end of the resistor R9 is connected to one end of the resistor R8, and the other end of the resistor R8 is connected to the base of the transistor Q2; one end of the resistor R10 is connected to the base of the transistor Q2, and the other end of the resistor R10 is grounded; the emitter of the transistor Q2 is grounded, and the collector of the transistor Q2 is connected to the gate of the transistor Q1; one end of the resistor R6 is connected to one end of the resistor R8, and the other end of the resistor R6 is connected to one end of the inductor L1; the source of the transistor Q1 is connected to the sampling circuit, and the drain of the transistor Q1 is grounded; one end of the resistor R11 is connected to the sampling circuit, and the other end of the resistor R11 is grounded; one end of the resistor R12 is connected to the sampling circuit, and the other end of the resistor R12 is grounded. end is grounded; one end of the resistor R13 is connected to the sampling circuit, and the other end of the resistor R13 is grounded; one end of the resistor R14 is connected to the sampling circuit, and the other end of the resistor R14 is grounded; one end of the resistor R2 is connected to the gate of the transistor Q1, and the other end of the resistor R2 is connected to one end of the inductor L1; the cathode of the diode D1 is connected to one end of the inductor L1, and the anode of the diode D1 is grounded; the other end of the inductor L1 is connected to the first pin and the second pin of the interface TP2; one end of the capacitor C12 is connected to the first pin and the second pin of the interface TP2, and the other end of the capacitor C12 is grounded; one end of the capacitor C13 is connected to the first pin and the second pin of the interface TP2, and the other end of the capacitor C13 is grounded.

[0022] In a possible implementation, the sampling circuit includes: a current sampling circuit and a voltage sampling circuit; the current sampling circuit is electrically connected to the control chip U3 and the chopper buck circuit respectively; the voltage sampling circuit is electrically connected to the control chip U3 and the chopper buck circuit respectively;

[0023] Wherein, the current sampling circuit is used to sample the speed regulating current output by the speed control circuit;

[0024] The voltage sampling circuit is used to sample the speed regulating voltage output by the speed control circuit.

[0025] In a possible implementation, the current sampling circuit includes: diodes DK1 and DK3; capacitor CK1; resistor RK3;

[0026] One end of the resistor RK3 is connected to the control chip U3, and the other end of the resistor RK3 is connected to the chopper buck circuit; the positive electrode of the diode DK1 is connected to the chopper buck circuit, and the negative electrode of the diode DK1 is connected to the second preset voltage; the negative electrode of the diode DK3 is connected to the chopper buck circuit, the positive electrode of the diode DK3 is connected to one end of the capacitor CK1, and the other end of the capacitor CK1 is connected to the control chip U3.

[0027] In a possible implementation, the voltage sampling circuit includes: resistors RK1, RK2, RK4, RK5; diodes DK2, DK4; capacitor CK2;

[0028] The cathode of diode DK2 is connected to the second preset voltage, the anode of diode DK2 is connected to the cathode of diode DK4, and the anode of diode DK4 is grounded; one end of resistor RK1 is connected to the chopper step-down circuit, the other end of resistor RK1 is connected to one end of resistor RK2, and the other end of resistor RK2 is connected to the anode of diode DK2; one end of resistor RK5 is connected to the anode of diode DK2, and the other end of resistor RK5 is grounded; one end of resistor RK4 is connected to the anode of diode DK2, and the other end of resistor RK4 is connected to the control chip U3; one end of capacitor CK2 is connected to the control chip U3, and the other end of capacitor CK2 is grounded.

[0029] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0030] The fan speed regulating device provided by the present invention converts the external input voltage into a first preset voltage and a second preset voltage suitable for the operation of the fan through a voltage conversion circuit, can handle different external input voltages, and converts them into voltage levels suitable for the operation of the fan through the voltage conversion circuit, which enhances the applicability and compatibility of the device, so that it can be widely used in the fan speed regulation needs under different voltage environments, can accurately control the electric energy supplied to the fan, avoid overvoltage or undervoltage operation, thereby effectively improving the energy utilization efficiency of the fan, reducing unnecessary power loss, and at the same time ensuring the safety of the fan speed regulating device during operation, avoiding dangerous hidden dangers caused by voltage mismatch. By providing an input adjustment terminal, the user or system is allowed to adjust the speed of the fan according to actual needs, and the speed control circuit can respond to these adjustment instructions, generate accurate speed adjustment voltage and current, and realize flexible and precise control of the fan speed. Through the integrated design, the user only needs to adjust the speed of the fan through the input adjustment terminal, without the need for complex operations or adjustments inside the fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A structural connection diagram of an embodiment of a fan speed regulating device and a controlled fan provided by the present invention;

[0033] Figure 2 A pin connection diagram of an embodiment of the control chip U3 provided by the present invention;

[0034] Figure 3 A circuit connection diagram of an embodiment of a voltage conversion circuit provided by the present invention;

[0035] Figure 4 A circuit connection diagram of an embodiment of a serial port transceiver circuit provided by the present invention;

[0036] Figure 5 A circuit connection diagram of an embodiment of a chopper step-down circuit provided by the present invention;

[0037] Figure 6 A circuit connection diagram of an embodiment of a current sampling circuit provided by the present invention;

[0038] Figure 7 A circuit connection diagram of an embodiment of a voltage sampling circuit provided by the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] The terms "first", "second", "third", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0041] See also Figure 1 , Figure 1 A structural connection diagram of an embodiment of a fan speed regulating device and a controlled fan provided by the present invention. In a specific embodiment of the present invention, a fan speed regulating device 100 is disclosed, comprising: a voltage conversion circuit 110, a speed control circuit 120, a sampling circuit 130 and an input adjustment terminal 140; the voltage conversion circuit 110 is electrically connected to the speed control circuit 120; the speed control circuit 120 is electrically connected to the sampling circuit 130, the input adjustment terminal 140 and the controlled fan 200 respectively;

[0042] The voltage conversion circuit 110 is used to convert the external input voltage into a first preset voltage and a second preset voltage;

[0043] The input adjustment terminal 140 is used to receive external input and generate a speed adjustment instruction;

[0044] The speed control circuit 120 is used to respond to the speed adjustment instruction and generate a speed adjustment voltage and a speed adjustment current;

[0045] The sampling circuit 130 is used to collect the speed regulating voltage and the speed regulating current output by the speed control circuit 120 .

[0046] In the above embodiment, the voltage conversion circuit 110 is responsible for safely and efficiently converting the external power supply voltage into two preset stable voltages - a first preset voltage and a second preset voltage. The two preset voltages are used to meet the power requirements of other components in the fan speed control device 100 under different working conditions, ensuring that the fan can operate at optimal performance while avoiding equipment damage or performance degradation caused by voltage fluctuations. As a preferred embodiment, the first preset voltage in the present invention is DC 5V, and the second preset voltage is DC 3.3V.

[0047] The input adjustment terminal 140 is a window for the user to interact with the system, allowing the user to input speed control instructions through knobs, buttons or digital interfaces. After these instructions are received by the input adjustment terminal 140, they are processed internally and converted into signals that can be recognized by the speed control circuit 120, which not only improves the convenience of operation, but also makes the speed control process more intuitive and flexible. As a preferred embodiment, the input adjustment terminal 140 in the present invention is an IO button, which is mainly composed of 5 non-self-locking button switches. One end of the switch is connected to the MCU lead as an INPUT input signal, and is pulled up to DC3.3V by a pull-up resistor, and the other end is connected to GND. When the switch is pressed, the input signal is pulled low. After the software in the MCU recognizes the pulse and continues for a period of time (the default is to continue 5 20ms pulse actions as a filtering anti-shake measure), the display content of the display screen 160 is controlled according to the defined "up", "down", "left", "right" and "adjust" buttons to realize functions such as moving the cursor and adjusting the duty cycle.

[0048] The speed control circuit 120 is the core control unit of the entire speed regulation device. It is responsible for receiving speed regulation instructions from the input regulation terminal 140, and generating corresponding speed regulation voltage and speed regulation current according to these instructions. The speed regulation voltage and speed regulation current are accurately transmitted to the controlled fan 200, thereby realizing accurate control of the fan speed. The speed control circuit 120 also has an intelligent regulation function, which can automatically adjust the output parameters according to the actual operating conditions of the fan to achieve the best speed regulation effect.

[0049] The sampling circuit 130 collects the speed regulating voltage and speed regulating current (i.e., the input voltage and input current of the controlled fan 200) output by the speed control circuit 120 in real time, and displays these parameters on the display screen 160 for visual adjustment of the duty cycle voltage regulation. The output current sampling is used to realize automatic protection of the circuit in the case of abnormality of the controlled fan 200 (too large or too small current). In addition, the data of the sampling circuit 130 can also be used for system optimization and fault diagnosis, providing strong support for subsequent maintenance and improvement.

[0050] Compared with the prior art, the fan speed control device 100 provided in this embodiment converts the external input voltage into a first preset voltage and a second preset voltage suitable for the operation of the fan through the voltage conversion circuit 110, can handle different external input voltages, and convert them into voltage levels suitable for the operation of the fan through the voltage conversion circuit 110, which enhances the applicability and compatibility of the device, so that it can be widely used in the fan speed control needs under different voltage environments, can accurately control the power supplied to the fan, avoid overvoltage or undervoltage operation, thereby effectively improving the energy utilization efficiency of the fan, reducing unnecessary power loss, and ensuring the safety of the fan speed control device 100 during operation, avoiding dangerous hidden dangers caused by voltage mismatch. By providing an input adjustment terminal 140, the user or system is allowed to adjust the speed of the fan according to actual needs, and the speed control circuit 120 can respond to these adjustment instructions, generate accurate speed adjustment voltage and current, and realize flexible and accurate control of the fan speed. Through the integrated design, the user only needs to adjust the speed of the fan through the input adjustment terminal 140, without the need for complex operations or adjustments inside the fan.

[0051] See also Figure 2 , Figure 2 This is a pin connection diagram of an embodiment of the control chip U3 provided by the present invention. In some embodiments of the present invention, the speed control circuit 120 further includes: a control chip U3 and a chopper buck circuit; the control chip U3 and the chopper buck circuit are electrically connected;

[0052] Among them, the control chip U3 is used to send a control signal according to the speed adjustment instruction;

[0053] The chopper step-down circuit is used to convert the external input voltage into the target speed voltage according to the control signal.

[0054] In the above embodiment, the speed control circuit 120 includes a pin connection circuit of the control chip U3 in addition to the control chip U3. As a preferred embodiment, the control chip U3 in this scheme is the STM32F103 minimum system. Through the JTAG burning software, the control of DC chopping and step-down, output voltage and fan current recovery are realized (the output voltage is sampled by the internal reference and output to the display screen 160 to read the current duty cycle and the current output voltage, which is convenient for adapting the fan voltage and visual speed regulation; current sampling is used to protect the circuit. If the fan current is too large or too small, the speed control circuit 120 will adjust the duty cycle of the control transistor Q1 to 0, so as to intelligently protect the circuit components from being burned), and the control display screen 160 displays and reads the IO button function.

[0055] The chopper step-down circuit controls the switching duty cycle of the transistor Q1 through the speed control circuit 120, converting the input low-voltage DC power of DC8V~DC36V (rated DC24V) into adjustable low-voltage DC power, thereby controlling the input voltage of the DC fan to achieve the speed regulation function.

[0056] In some embodiments of the present invention, a display screen 160 is further included; the display screen 160 is electrically connected to the serial port transceiver circuit 150; the display screen 160 is used to display the working status of the controlled fan 200 according to the speed adjustment voltage and the speed adjustment current.

[0057] In the above embodiment, the display screen 160 mainly has 5 lines (this solution uses a 3.37-inch display screen 160 with a size of 102.7 (L) × 69.1 (W) × 7.0 (H) and a resolution of 240 × 128. The main parameters are as follows Figure 7 The first line of the display content is the fast adjustment mode (MODE), which is divided into 4 speed levels: fast, medium, slow and custom, corresponding to 100%, 50%, 10% and manual adjustment speed respectively. The second line of the display content is the current fan speed (FAN SPEED), which displays and can adjust the duty cycle in custom mode, with a total of 100 levels from 0% to 100%. The third line of the display content is the current fan voltage (FAN VOLTAGE), which displays the current output voltage and is easy to adjust to suit various types of fans. The fourth line of the display content is the current fan current (FAN CURRENT), which displays the current output current and is easy to read the current current information for fault identification, etc.

[0058] See also Figure 3 , Figure 3A circuit connection diagram of an embodiment of a voltage conversion circuit 110 provided by the present invention. In some embodiments of the present invention, the voltage conversion circuit 110 includes: voltage conversion chips U1 and U2; capacitors C1, C2, C3, C4, C5, C6, C7, and C8;

[0059] The first pin of the voltage conversion chip U2 is connected to the external input voltage, and the third pin of the voltage conversion chip U2 is respectively connected to the first pin and the third pin of the voltage conversion chip U1; the second pin of the voltage conversion chip U2 is connected to the second pin of the voltage conversion chip U1; the capacitor C1 is connected in parallel to the first pin and the second pin of the voltage conversion chip U2; the capacitor C2 is connected in parallel to the first pin and the second pin of the voltage conversion chip U2; the capacitors C3, C4, C5, and C6 are respectively connected to the third pin and the second pin of the voltage conversion chip U2; the capacitors C7 and C8 are respectively connected to the fifth pin and the second pin of the voltage conversion chip U1.

[0060] In the above embodiment, the acceptable input voltage of the voltage conversion circuit 110 is DC 8-36V, and the voltage conversion chip U1 is an LDO chip, which is called a low dropout linear regulator chip (Low Dropout Regulator), which is an integrated circuit for providing stable and reliable voltage output. The main function of the LDO chip is to convert the input voltage into a target output voltage, and to maintain the stability of the output voltage when the input voltage fluctuates. In the present invention, the chip can convert a DC 5V voltage into a DC 3.3V voltage.

[0061] The voltage conversion chip U2 is model N78050M-1000, which is a DC / DC (direct current to direct current) converter module that converts one DC voltage into another DC voltage to meet the power requirements of different circuits or devices. In the present invention, the voltage conversion chip U2 converts the input voltage of the voltage conversion circuit 110 into a DC 5V voltage output.

[0062] The first pin of the voltage conversion chip U2 receives an external input voltage and is the power input point of the entire voltage conversion circuit 110. The third pin of the voltage conversion chip U2 is connected to the first pin and the third pin of the voltage conversion chip U1, and can be used to transmit voltage, current or control signals. The voltage conversion chip U2 can be used as a pre-voltage regulator to provide a stable input voltage or control signal for U1. The voltage conversion chip U2 will first perform preliminary processing on the input voltage (such as voltage reduction, voltage stabilization, etc.), and then pass the processed voltage to the voltage conversion chip U1. The voltage conversion chip U1 will then perform further voltage conversion or regulation as needed, and finally output the required voltage.

[0063] See also Figure 4 , Figure 4The circuit connection diagram of an embodiment of the serial port transceiver circuit 150 provided by the present invention, in some embodiments of the present invention, further includes a serial port transceiver circuit 150, the serial port transceiver circuit 150 is electrically connected to the speed control circuit 120; the serial port transceiver circuit 150 is used to transmit the speed adjustment voltage and the speed adjustment current. The serial port transceiver circuit 150 includes: a chip U4, capacitors C9, C10, C11, C14, C15;

[0064] One end of capacitor C9 is grounded, and the other end of capacitor C9 is connected to the sixteenth pin of chip U4; the two ends of capacitor C10 are connected in parallel to the second pin and the sixteenth pin of chip U4; the two ends of capacitor C11 are connected in parallel to the first pin and the third pin of chip U4; the two ends of capacitor C14 are connected in parallel to the fourth pin and the fifth pin of chip U4; one end of capacitor C15 is grounded, and the other end of capacitor C15 is connected to the sixth pin of chip U4.

[0065] In the above embodiment, the signal of chip U4 is MAX3232, which is a chip widely used in serial communication, including two drivers (transmitters) and two receivers, which are used to send and receive data respectively, and support two-way communication. Chip U4 realizes the communication between the speed control circuit 120 and the display screen 160, and transmits the speed adjustment voltage and speed adjustment current output by the speed control circuit 120 to the display screen 160 for display, so as to further understand the status of the controlled fan 200.

[0066] When it is necessary to send speed adjustment information, chip U4 converts parallel data into serial data and outputs it through its sending pins (TXD, RXD pins). During the sending process, capacitors C10, C11, etc. play a filtering role to ensure the stability and clarity of the sent signal. The speed control circuit 120 sends speed feedback or request information to the receiving pins (such as SCI RX, SCI TX pins) of chip U4 through the serial port. After the received signal is filtered by capacitors C14, etc., it is converted from serial to parallel by chip U4 and processed into recognizable data. Capacitors C9 and C15 act as decoupling capacitors to help reduce the impact of power supply noise on chip U4 and ensure the stable operation of the chip. Capacitors C10, C11 and C14 play a filtering role in the circuit, which helps to eliminate high-frequency noise and interference in the signal and improve the signal-to-noise ratio and reliability of the signal.

[0067] See also Figure 5 , Figure 5 A circuit connection diagram of an embodiment of a chopper buck circuit provided by the present invention. In some embodiments of the present invention, the chopper buck circuit includes: resistors R2, R6, R8, R9, R10, R11, R12, R13, R14; diode D1, transistors Q1, Q2; capacitors C12, C13; inductor L1; interface TP2;

[0068] One end of the resistor R9 is connected to the control chip U3, the other end of the resistor R9 is connected to one end of the resistor R8, and the other end of the resistor R8 is connected to the base of the transistor Q2; one end of the resistor R10 is connected to the base of the transistor Q2, and the other end of the resistor R10 is grounded; the emitter of the transistor Q2 is grounded, and the collector of the transistor Q2 is connected to the gate of the transistor Q1; one end of the resistor R6 is connected to one end of the resistor R8, and the other end of the resistor R6 is connected to one end of the inductor L1; the source of the transistor Q1 is connected to the sampling circuit 130, and the drain of the transistor Q1 is grounded; one end of the resistor R11 is connected to the sampling circuit 130, and the other end of the resistor R11 is grounded; one end of the resistor R12 is connected to the sampling circuit 130, and the collector of the transistor R12 is connected to the gate of the transistor Q1. The other end is grounded; one end of the resistor R13 is connected to the sampling circuit 130, and the other end of the resistor R13 is grounded; one end of the resistor R14 is connected to the sampling circuit 130, and the other end of the resistor R14 is grounded; one end of the resistor R2 is connected to the gate of the transistor Q1, and the other end of the resistor R2 is connected to one end of the inductor L1; the cathode of the diode D1 is connected to one end of the inductor L1, and the anode of the diode D1 is grounded; the other end of the inductor L1 is connected to the first pin and the second pin of the interface TP2; one end of the capacitor C12 is connected to the first pin and the second pin of the interface TP2, and the other end of the capacitor C12 is grounded; one end of the capacitor C13 is connected to the first pin and the second pin of the interface TP2, and the other end of the capacitor C13 is grounded.

[0069] In the above embodiment, the chopper buck circuit is also called a switching buck circuit or a Buck converter, which controls the current through the inductor by quickly switching a field effect transistor MOSFET (transistor Q1) to achieve voltage reduction.

[0070] The control chip U3 provides a control signal to the base of transistor Q2 through resistors R9 and R8. Q2 acts as a driver, and its collector is connected to the gate of MOSFET (transistor Q1) to amplify the control signal and drive MOSFET (transistor Q1). When Q2 is turned on, the gate of MOSFET (transistor Q1) is pulled down (assuming it is an N-channel MOSFET), and MOSFET (transistor Q1) is turned on, allowing current to pass through the bypass of inductor L1 and diode D1 (D1 is turned off at this time). The current establishes a magnetic field in the inductor and stores energy. When the MOSFET (transistor Q1) is turned off (Q2 is turned off), the current in the inductor cannot be interrupted immediately, so it will continue to flow through diode D1 to form a loop. The inductor releases its stored energy and provides current to the load, while the voltage is reduced to a value lower than the input voltage. Capacitors C12 and C13 are used to smooth the output voltage and reduce voltage fluctuations caused by the rapid switching of MOSFET (transistor Q1). The sampling circuit 130 composed of resistors R11, R12, R13, and R14 is used to monitor the output voltage and feed the information back to the control chip U3. The control chip adjusts the base voltage of Q2 according to the feedback signal, thereby controlling the switching frequency and duty cycle of Q1 to keep the output voltage stable.

[0071] In some embodiments of the present invention, the sampling circuit 130 includes: a current sampling circuit 130 and a voltage sampling circuit 130; the current sampling circuit 130 is electrically connected to the control chip U3 and the chopper buck circuit respectively; the voltage sampling circuit 130 is electrically connected to the control chip U3 and the chopper buck circuit respectively;

[0072] The current sampling circuit 130 is used to sample the speed regulating current output by the speed control circuit 120;

[0073] The voltage sampling circuit 130 is used to sample the speed regulating voltage output by the speed control circuit 120 .

[0074] In the above embodiment, the main task of the current sampling circuit 130 is to accurately measure the speed regulating current generated during the output of the speed control circuit 120, which directly reflects the change of the motor load and the control effect of the chopper buck circuit on the current. The current sampling circuit 130 transmits the collected current signal to the control chip U3 for processing after appropriate amplification, filtering and analog-to-digital conversion (ADC). The control chip adjusts the duty cycle or switching frequency of the chopper buck circuit according to the size and change trend of the current value, thereby realizing accurate control of the motor speed.

[0075] The voltage sampling circuit 130 is responsible for collecting the speed regulation voltage during the output of the speed control circuit 120, which not only reflects the stability of the power supply and the conversion efficiency of the chopper buck circuit, but is also closely related to the torque and speed of the motor. The voltage sampling circuit 130 is usually implemented by directly measuring the output voltage of the chopper buck circuit or the power supply voltage of the motor drive circuit. In order to ensure the measurement accuracy, high-precision resistor voltage division, operational amplifier follower or dedicated voltage sensor solutions are usually adopted.

[0076] See also Figure 6 , Figure 6 This is a circuit connection diagram of an embodiment of the current sampling circuit 130 provided by the present invention. In some embodiments of the present invention, the current sampling circuit 130 includes: diodes DK1 and DK3; capacitor CK1; resistor RK3;

[0077] One end of the resistor RK3 is connected to the control chip U3, and the other end of the resistor RK3 is connected to the chopper buck circuit; the positive electrode of the diode DK1 is connected to the chopper buck circuit, and the negative electrode of the diode DK1 is connected to the second preset voltage; the negative electrode of the diode DK3 is connected to the chopper buck circuit, the positive electrode of the diode DK3 is connected to one end of the capacitor CK1, and the other end of the capacitor CK1 is connected to the control chip U3.

[0078] In the above embodiment, in this circuit, the diode DK1 plays the role of half-wave rectification. When the current in the chopper buck circuit is positive (i.e., flowing to the positive electrode of the diode DK1), the diode is turned on, allowing the current to pass and flow to the second preset voltage. In this process, the diode DK1 actually limits the current flow direction, ensuring that only the forward current (relative to its polarity) can affect the subsequent circuit. However, in this particular configuration, the diode DK1 may be more used to protect or limit the current, rather than directly participate in current sampling.

[0079] When the current in the chopper buck circuit is negative (i.e., flowing to the cathode of diode DK3), diode DK3 is turned on, allowing current to pass and flow to capacitor CK1 and resistor RK3. Diode DK3 is actually "capturing" negative current because in most motor control or power management applications, the direction and magnitude of the current are of concern, not just its absolute value.

[0080] Capacitor CK1 plays a filtering role here. When diode DK3 is turned on and current passes through, capacitor CK1 will start to charge, and the voltage across it will gradually rise until it reaches a stable value (depending on the current and the capacitance). This voltage value reflects the average or peak value of the negative current in the chopper buck circuit (depending on the charging and discharging characteristics of the capacitor). By adjusting the capacitance of the capacitor, the response speed and sensitivity of the circuit to current changes can be changed.

[0081] When current passes through RK3, according to Ohm's law, a voltage drop proportional to the current will be generated across RK3. This voltage drop is superimposed on the voltage on capacitor CK1 and transmitted to the control chip U3. The resistance value of resistor RK3 determines the proportional factor of the current-to-voltage conversion, that is, the gain of the circuit.

[0082] See also Figure 7 , Figure 7 A circuit connection diagram of an embodiment of the voltage sampling circuit 130 provided by the present invention. In some embodiments of the present invention, the voltage sampling circuit 130 includes: resistors RK1, RK2, RK4, RK5; diodes DK2, DK4; capacitor CK2;

[0083] The cathode of diode DK2 is connected to the second preset voltage, the anode of diode DK2 is connected to the cathode of diode DK4, and the anode of diode DK4 is grounded; one end of resistor RK1 is connected to the chopper step-down circuit, the other end of resistor RK1 is connected to one end of resistor RK2, and the other end of resistor RK2 is connected to the anode of diode DK2; one end of resistor RK5 is connected to the anode of diode DK2, and the other end of resistor RK5 is grounded; one end of resistor RK4 is connected to the anode of diode DK2, and the other end of resistor RK4 is connected to the control chip U3; one end of capacitor CK2 is connected to the control chip U3, and the other end of capacitor CK2 is grounded.

[0084] In the above embodiment, the resistors RK1 and RK2 are connected in series between the chopper buck circuit and the diode DK2 to form a voltage divider. After the output voltage of the chopper buck circuit is divided by RK1 and RK2, a lower voltage is generated at the other end of RK2 (i.e., the positive electrode of the diode DK2). This voltage not only reflects the output voltage of the chopper buck circuit, but also reduces the voltage directly applied to the subsequent circuit through the voltage division effect, thereby playing a protective role.

[0085] Diodes DK2 and DK4 form a simple protection circuit, with the positive electrode of diode DK2 connected to the voltage dividing point and its negative electrode connected to the second preset voltage. When the voltage at the voltage dividing point exceeds the second preset voltage, diode DK2 is turned on to discharge the excess voltage to the second preset voltage to prevent the subsequent circuit from being damaged. DK4 is a reverse protection diode, with its negative electrode connected to the positive electrode of DK2 and its positive electrode grounded. When the positive electrode voltage of diode DK2 is lower than the ground potential, diode DK4 is turned on to prevent the negative voltage from damaging the subsequent circuit.

[0086] The resistor RK4 transmits the divided voltage signal to the control chip U3. Since the resistor RK4 is directly connected to the input terminal of the control chip, the selection of its resistance value needs to take into account the control chip's requirements for the input voltage range, as well as the attenuation and noise problems during signal transmission.

[0087] Capacitor CK2 is connected in parallel with resistor RK4 to play a filtering role. It can smooth out high-frequency noise and ripples in the voltage signal, making the voltage signal transmitted to the control chip U3 more stable and reliable. The capacity and type of capacitor CK2 need to be selected according to the specific noise frequency and filtering requirements.

[0088] Resistor RK5 is connected between the positive electrode of diode DK2 and ground to form a discharge loop. When the circuit is powered off or the output voltage of the chopper step-down circuit drops suddenly, a certain amount of charge may remain on capacitor CK2. RK5 provides a discharge path for these charges to prevent surge current or damage to the control chip U3 when power is restored.

[0089] In summary, the fan speed control device 100 provided by the present invention converts the external input voltage into a first preset voltage and a second preset voltage suitable for the operation of the fan through the voltage conversion circuit 110, can handle different external input voltages, and converts them into voltage levels suitable for the operation of the fan through the voltage conversion circuit 110, which enhances the applicability and compatibility of the device, so that it can be widely used in the fan speed control needs under different voltage environments, can accurately control the power supplied to the fan, avoid overvoltage or undervoltage operation, thereby effectively improving the energy utilization efficiency of the fan, reducing unnecessary power loss, and at the same time ensuring the safety of the fan speed control device 100 during operation, avoiding dangerous hidden dangers caused by voltage mismatch. By providing an input adjustment terminal 140, the user or system is allowed to adjust the speed of the fan according to actual needs, and the speed control circuit 120 can respond to these adjustment instructions, generate accurate speed adjustment voltage and current, and realize flexible and precise control of the fan speed. Through the integrated design, the user only needs to adjust the speed of the fan through the input adjustment terminal 140, without the need for complex operations or adjustments inside the fan.

[0090] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0091] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0092] In the several embodiments provided in the present application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0093] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0094] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0095] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not recorded in the present disclosure. The description and examples are regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

[0096] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0097] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A fan speed regulating device, characterized in that: include: A voltage conversion circuit, a speed control circuit, a sampling circuit and an input adjustment terminal; the voltage conversion circuit is electrically connected to the speed control circuit; the speed control circuit is electrically connected to the sampling circuit, the input adjustment terminal and the controlled fan respectively; Wherein, the voltage conversion circuit is used to convert the external input voltage into a first preset voltage and a second preset voltage; The input adjustment terminal is used to receive external input and generate a speed adjustment instruction; The speed control circuit is used to generate a speed regulating voltage and a speed regulating current in response to the speed regulating instruction; The sampling circuit is used to collect the speed regulating voltage and the speed regulating current output by the speed control circuit.

2. The fan speed regulating device according to claim 1, characterized in that: The speed control circuit further includes: a control chip U3 and a chopper buck circuit; the control chip U3 and the chopper buck circuit are electrically connected; Wherein, the control chip U3 is used to send a control signal according to the speed adjustment instruction; The chopper step-down circuit is used for converting the external input voltage into a target speed voltage according to the control signal.

3. The fan speed regulating device according to claim 1, characterized in that: It also includes a serial port transceiver circuit, which is electrically connected to the speed control circuit; the serial port transceiver circuit is used to transmit the speed adjustment voltage and the speed adjustment current.

4. The fan speed regulating device according to claim 3, characterized in that: It also includes a display screen; the display screen; the display screen is electrically connected to the serial port transceiver circuit; the display screen is used to display the working status of the controlled fan according to the speed adjustment voltage and the speed adjustment current.

5. The fan speed regulating device according to claim 1, characterized in that: The voltage conversion circuit includes: voltage conversion chips U1, U2; capacitors C1, C2, C3, C4, C5, C6, C7, C8; The first pin of the voltage conversion chip U2 is connected to the external input voltage, and the third pin of the voltage conversion chip U2 is respectively connected to the first pin and the third pin of the voltage conversion chip U1; the second pin of the voltage conversion chip U2 is connected to the second pin of the voltage conversion chip U1; the capacitor C1 is connected in parallel to the first pin and the second pin of the voltage conversion chip U2; the capacitor C2 is connected in parallel to the first pin and the second pin of the voltage conversion chip U2; the capacitors C3, C4, C5, and C6 are respectively connected to the third pin and the second pin of the voltage conversion chip U2; the capacitors C7 and C8 are respectively connected to the fifth pin and the second pin of the voltage conversion chip U1.

6. The fan speed regulating device according to claim 3, characterized in that: The serial port transceiver circuit includes: a chip U4, capacitors C9, C10, C11, C14, and C15; One end of the capacitor C9 is grounded, and the other end of the capacitor C9 is connected to the sixteenth pin of the chip U4; the two ends of the capacitor C10 are connected in parallel to the second pin and the sixteenth pin of the chip U4; the two ends of the capacitor C11 are connected in parallel to the first pin and the third pin of the chip U4; the two ends of the capacitor C14 are connected in parallel to the fourth pin and the fifth pin of the chip U4; one end of the capacitor C15 is grounded, and the other end of the capacitor C15 is connected to the sixth pin of the chip U4.

7. The fan speed regulating device according to claim 2, characterized in that: The chopper step-down circuit includes: resistors R2, R6, R8, R9, R10, R11, R12, R13, R14; diode D1, transistors Q1, Q2; capacitors C12, C13; inductor L1; interface TP2; One end of the resistor R9 is connected to the control chip U3, and the other end of the resistor R9 is connected to one end of the resistor R8, and the other end of the resistor R8 is connected to the base of the transistor Q2; one end of the resistor R10 is connected to the base of the transistor Q2, and the other end of the resistor R10 is grounded; the emitter of the transistor Q2 is grounded, and the collector of the transistor Q2 is connected to the gate of the transistor Q1; one end of the resistor R6 is connected to one end of the resistor R8, and the other end of the resistor R6 is connected to one end of the inductor L1; the source of the transistor Q1 is connected to the sampling circuit, and the drain of the transistor Q1 is grounded; one end of the resistor R11 is connected to the sampling circuit, and the other end of the resistor R11 is grounded; one end of the resistor R12 is connected to the sampling circuit, and the resistor R12 The other end of the resistor R13 is connected to the sampling circuit, and the other end of the resistor R13 is grounded; one end of the resistor R14 is connected to the sampling circuit, and the other end of the resistor R14 is grounded; one end of the resistor R2 is connected to the gate of the transistor Q1, and the other end of the resistor R2 is connected to one end of the inductor L1; the cathode of the diode D1 is connected to one end of the inductor L1, and the anode of the diode D1 is grounded; the other end of the inductor L1 is connected to the first pin and the second pin of the interface TP2; one end of the capacitor C12 is connected to the first pin and the second pin of the interface TP2, and the other end of the capacitor C12 is grounded; one end of the capacitor C13 is connected to the first pin and the second pin of the interface TP2, and the other end of the capacitor C13 is grounded.

8. The fan speed regulating device according to claim 2, characterized in that: The sampling circuit includes: a current sampling circuit and a voltage sampling circuit; the current sampling circuit is electrically connected to the control chip U3 and the chopper buck circuit respectively; the voltage sampling circuit is electrically connected to the control chip U3 and the chopper buck circuit respectively; Wherein, the current sampling circuit is used to sample the speed regulating current output by the speed control circuit; The voltage sampling circuit is used for sampling the speed regulating voltage output by the speed control circuit.

9. The fan speed regulating device according to claim 8, characterized in that: The current sampling circuit includes: diodes DK1, DK3; capacitor CK1; resistor RK3; One end of the resistor RK3 is connected to the control chip U3, and the other end of the resistor RK3 is connected to the chopper buck circuit; the positive electrode of the diode DK1 is connected to the chopper buck circuit, and the negative electrode of the diode DK1 is connected to the second preset voltage; the negative electrode of the diode DK3 is connected to the chopper buck circuit, the positive electrode of the diode DK3 is connected to one end of the capacitor CK1, and the other end of the capacitor CK1 is connected to the control chip U3.

10. The fan speed regulating device according to claim 8, characterized in that: The voltage sampling circuit includes: resistors RK1, RK2, RK4, RK5; diodes DK2, DK4; capacitor CK2; The cathode of the diode DK2 is connected to the second preset voltage, the anode of the diode DK2 is connected to the cathode of the diode DK4, and the anode of the diode DK4 is grounded; one end of the resistor RK1 is connected to the chopper step-down circuit, the other end of the resistor RK1 is connected to one end of the resistor RK2, and the other end of the resistor RK2 is connected to the anode of the diode DK2; one end of the resistor RK5 is connected to the anode of the diode DK2, and the other end of the resistor RK5 is grounded; one end of the resistor RK4 is connected to the anode of the diode DK2, and the other end of the resistor RK4 is connected to the control chip U3; one end of the capacitor CK2 is connected to the control chip U3, and the other end of the capacitor CK2 is grounded.

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