Fan speed regulation control circuit

Abstract

The utility model relates to the technical field of fans, and discloses a fan speed regulation control circuit, which comprises a switching power supply; the main control circuit is used for adjusting the rotating speed of the fan by outputting a PWM signal; the PWM speed regulation circuit is used for receiving the PWM signal and regulating the current or voltage value output to the fan according to the duty ratio of the PWM signal; a PWM amplification circuit; the direct-current fan interface circuit is used for connecting the direct-current fan and the PWM amplifying circuit; the switching power supply has the characteristics of low power consumption and high efficiency, the switching speed is high, the frequency is high, the PWM speed regulation circuit directly controls the power supply time of the motor to keep the high-efficiency operation of the fan, and the fan also keeps a high energy efficiency ratio in a low-speed state, so that the effects of saving energy and reducing consumption are achieved; the main control circuit outputs and generates accurate PWM signals, accurate adjustment of the rotating speed of the draught fan is achieved by adjusting the duty ratio of the PWM signals, and the circuit can adapt to different types of direct current draught fans and meet the working requirements of different draught fans.

Description

Technical Field

[0001] This utility model relates to the field of wind turbine technology, specifically a wind turbine speed control circuit. Background Technology

[0002] A fan is a machine that uses input mechanical energy to increase gas pressure and discharge gas; it is a type of driven fluid machinery. Fan speed regulation refers to controlling parameters such as air volume, air pressure, power, and noise by changing the fan's rotational speed, thereby achieving optimal operating conditions.

[0003] A search revealed that patent application number CN202320945073.2 discloses a speed-regulating fan control circuit comprising: an MCU controller; a protection unit connected to the IO1 port of the MCU controller; a drive unit connected at one end to the protection unit and at the other end to a DC power supply; and a charging / discharging unit connected between the drive unit and the fan. The charging / discharging unit includes a capacitor and a resistor connected in parallel. The fan is connected to the IO2 port of the MCU controller for transmitting feedback signals. This invention controls the on / off state of various transistors through signals output by the MCU controller, thereby driving the fan. This achieves fan driving and speed regulation with fewer components, simplifying circuit board design and improving the smoothness of fan speed regulation, enabling timely fan speed adjustment.

[0004] Current fan control circuits have high power consumption and low efficiency, which prevents the fan from maintaining a high energy efficiency ratio, resulting in high energy consumption. Furthermore, current fan speed regulation methods, such as resistance speed regulation, frequency conversion speed regulation, and hydraulic coupling speed regulation, cannot achieve precise control of the fan speed. Therefore, we need to propose a fan speed control circuit. Utility Model Content

[0005] The purpose of this invention is to provide a fan speed control circuit. The switching power supply features low power consumption, high efficiency, fast conversion speed, and high frequency. The PWM speed control circuit directly controls the power supply time of the motor to maintain high-efficiency operation of the fan. The fan maintains a high energy efficiency ratio even at low speeds, thus achieving energy saving and consumption reduction. The main control circuit outputs a precise PWM signal, and by adjusting the duty cycle of the PWM signal, the fan speed can be precisely adjusted. Furthermore, this circuit can adapt to different types of DC fans, meeting the working requirements of different fans, thereby solving the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a fan speed control circuit, comprising:

[0007] A switching power supply used to convert input alternating current (AC) to direct current (DC);

[0008] The main control circuit adjusts the fan speed by outputting a PWM signal;

[0009] A PWM speed control circuit used to receive PWM signals and adjust the current or voltage output to the fan according to the duty cycle of the PWM signals.

[0010] A PWM amplifier circuit that can amplify the weak signal output by a PWM speed control circuit.

[0011] DC fan interface circuit for connecting DC fan and PWM amplifier circuit;

[0012] The main control circuit, PWM speed control circuit, PWM amplifier circuit, and DC fan interface circuit are connected in sequence, and the main control circuit, PWM amplifier circuit, and DC fan interface circuit are all electrically connected to the switching power supply.

[0013] Preferably, the switching power supply includes a power chip U2, a transformer T1, a voltage regulator chip U5, and a voltage regulator chip U6. The power chip U2 is connected to the transformer T1. A diode D16 and a diode D17 are connected between pin 4 of the power chip U2 and pin 5 of the transformer T1. A diode D4 is connected to pin 6 of the transformer T1. A resistor R4 is connected between pin 1 of the voltage regulator chip U5 and diode D4. A resistor R30 is connected between pin 1 of the voltage regulator chip U6 and diode D4.

[0014] Preferably, pins 5, 6, 7, and 8 of the power chip U2 are connected to diode D14. One end of diode D14 is connected to resistor R23, resistor R7, and capacitor C8 to form a closed loop. The terminals of resistor R23 and capacitor C8 are sequentially connected to resistor R3, connector CN4, connector CN1, and diode D3. One end of diode D3 is connected to a 220-240V power supply voltage.

[0015] Preferably, a Zener diode ZD2 and a diode D15 are connected between the terminals of diodes D16 and D17 and pin 3 of the power chip U2, and capacitors EC13, C7, EC99, and EC100 are connected in parallel to the terminals of diodes D16 and D17.

[0016] Preferably, the main control circuit includes a main control chip U1, pin 3 of the voltage regulator chip U5 is connected to pin 12 of the main control chip U1, and the PWM speed control circuit is connected to pin 43 of the voltage regulator chip U5.

[0017] Preferably, the PWM speed control circuit includes a transistor Q2, with a resistor R12 and a capacitor C2 connected in parallel between the base and emitter of the transistor Q2, and a resistor R4 connected to the base of the transistor Q2, one end of which is connected to pin 43 of the voltage regulator chip U5.

[0018] Preferably, the PWM amplifier circuit includes a MOSFET Q3 and a transistor D2. A resistor R26 is connected between the gate and source of the MOSFET Q3. A resistor R25 is also connected to the collector of the transistor Q2 on the gate of the MOSFET Q3. A capacitor EC4, a capacitor C23, an inductor L10 and a diode D4 are connected in parallel between the collector and emitter of the transistor D2. The terminals of the inductor L10 and the diode D4 are connected to the drain of the MOSFET Q3.

[0019] Preferably, the DC fan interface circuit includes a terminal block M1, pin 1 of which is connected to the emitter of transistor D2, and pin 2 of which is connected to the base and collector of transistor D2.

[0020] Compared with the prior art, the beneficial effects of this utility model are:

[0021] 1. The switching power supply of this utility model has the characteristics of low power consumption and high efficiency, fast conversion speed and high frequency. The PWM speed regulation circuit directly controls the power supply time of the motor to maintain the high efficiency of the fan. The fan maintains a high energy efficiency ratio even at low speed, which plays a role in energy saving and consumption reduction.

[0022] 2. The main control circuit of this utility model outputs a precise PWM signal. By adjusting the duty cycle of the PWM signal, the fan speed can be precisely adjusted. Furthermore, this circuit can adapt to different types of DC fans and meet the working requirements of different fans. Attached Figure Description

[0023] Figure 1 This is a block diagram of the present invention;

[0024] Figure 2 This is the circuit diagram of the switching power supply of this utility model;

[0025] Figure 3 This is a circuit connection diagram of the main control circuit, PWM speed control circuit, PWM amplifier circuit, and DC fan interface circuit of this utility model;

[0026] Figure 4 This is a circuit diagram of the main control circuit of this utility model;

[0027] Figure 5 This is the circuit diagram of the PWM speed control circuit of this utility model;

[0028] Figure 6 This is a circuit diagram of the PWM amplifier circuit and DC fan interface circuit of this utility model. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] Please see Figure 1-6 This utility model provides a technical solution: a fan speed control circuit, comprising:

[0031] A switching power supply used to convert input alternating current (AC) to direct current (DC);

[0032] The switching power supply includes a power chip U2, a transformer T1, a voltage regulator chip U5, and a voltage regulator chip U6. The power chip U2 is connected to the transformer T1. A diode D16 and a diode D17 are connected between pin 4 of the power chip U2 and pin 5 of the transformer T1. A diode D4 is connected to pin 6 of the transformer T1. A resistor R4 is connected between pin 1 of the voltage regulator chip U5 and diode D4. A resistor R30 is connected between pin 1 of the voltage regulator chip U6 and diode D4.

[0033] The terminals of pins 5, 6, 7, and 8 of the power chip U2 are connected to diode D14. One end of diode D14 is connected to resistor R23, resistor R7, and capacitor C8 to form a closed loop. The terminals of resistor R23 and capacitor C8 are connected in sequence to resistor R3, connector CN4, connector CN1, and diode D3. One end of diode D3 is connected to a 220-240V power supply voltage.

[0034] The terminals of diodes D16 and D17 are connected to pin 3 of power chip U2 via Zener diodes ZD2 and D15. Furthermore, the terminals of diodes D16 and D17 are connected in parallel with capacitors EC13, C7, EC99, and EC100.

[0035] The input 220-240V voltage enters the circuit through rectifier diode D3 to provide a high-voltage DC power supply, and capacitor C8 is used for filtering to stabilize the power supply voltage.

[0036] Transformer T1 is used to reduce the input voltage. Its primary winding is connected to a high-voltage DC power supply, while its secondary winding outputs a lower AC voltage. Diodes D14 and D4 are rectifier diodes that convert AC to DC. Power chip U2 can regulate the input voltage to the required output voltage. Voltage regulator chips U5 and U6 are used to provide stable 5V and 15V outputs, respectively.

[0037] The main control circuit adjusts the fan speed by outputting a PWM signal;

[0038] The main control circuit includes a main control chip U1, pin 3 of the voltage regulator chip U5 is connected to pin 12 of the main control chip U1, and the PWM speed control circuit is connected to pin 43 of the voltage regulator chip U5.

[0039] Pin 12 of the main control chip U1 provides 5V power to power the main control circuit. Pins 8, 9, 10, and 11 of the main control chip U1 are typically used for analog input or digital output and can be connected to sensors or other components. Among them, pins 8 and 9 of the main control chip U1 are used to connect to an external crystal oscillator to provide clock signals.

[0040] A PWM speed control circuit used to receive PWM signals and adjust the current or voltage output to the fan according to the duty cycle of the PWM signals.

[0041] The PWM speed control circuit includes a transistor Q2. A resistor R12 and a capacitor C2 are connected in parallel between the base and emitter of the transistor Q2. A resistor R4 is connected to the base of the transistor Q2. One end of the resistor R4 is connected to pin 43 of the voltage regulator chip U5.

[0042] Transistor Q2 acts as a switching element, controlling the switching state of the load. It regulates the current between the collector (C) and emitter (E) by controlling the base (B) current. Resistors R4 and R12 are connected between the base pin and the input signal (A), limiting the base current to protect the transistor and ensure its normal operation. Capacitor C2 is used for filtering and coupling, forming an RC time constant circuit with resistor R12. This allows the circuit to provide smooth signal changes when the input A varies, preventing transient interference.

[0043] A PWM amplifier circuit that can amplify the weak signal output by a PWM speed control circuit.

[0044] The PWM amplifier circuit includes a MOSFET Q3 and a transistor D2. A resistor R26 is connected between the gate and source of the MOSFET Q3. A resistor R25 is also connected to the collector of the transistor Q2 on the gate of the MOSFET Q3. A capacitor EC4, a capacitor C23, an inductor L10, and a diode D4 are connected in parallel between the collector and emitter of the transistor D2. The terminals of the inductor L10 and the diode D4 are connected to the drain of the MOSFET Q3.

[0045] A 15V power supply provides high-voltage power to the fan, and MOSFET Q3 acts as a switching element to control the fan's on / off state. When a signal is applied to the gate (G), the MOSFET turns on, allowing current to flow through the fan and turning it on; when the signal is low, the MOSFET turns off, and the fan stops working.

[0046] Resistor R25 pulls the input signal from the device to ensure the normal operation of MOSFET Q3. Resistor R26 works with the gate to set the threshold, helping to control the MOSFET's on and off states. Diode D4 prevents reverse current and protects the circuit. Transistor D2 enables fast switching, ensuring that the signal is not damaged by reverse current. Inductor L10 reduces current fluctuations during switching, protecting the fan and other components.

[0047] When the input signal B is high, the MOSFET (Q3) is turned on, allowing current from the 15V power supply to flow into the fan (M1), and the fan starts. When the signal B is low, the MOSFET is turned off, and the fan stops working. Resistors R25 and R26 work together on the gate of the MOSFET to control its turn-on sensitivity, thereby ensuring continuous and reliable control of the fan operation.

[0048] DC fan interface circuit for connecting DC fan and PWM amplifier circuit;

[0049] The DC fan interface circuit includes a terminal block M1, pin 1 of which is connected to the emitter of transistor D2, and pin 2 of which is connected to the base and collector of transistor D2.

[0050] The main control circuit, PWM speed control circuit, PWM amplifier circuit, and DC fan interface circuit are connected in sequence, and the main control circuit, PWM amplifier circuit, and DC fan interface circuit are all electrically connected to the switching power supply.

[0051] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fan speed control circuit, characterized in that, include: A switching power supply used to convert input alternating current (AC) to direct current (DC); The main control circuit adjusts the fan speed by outputting a PWM signal; A PWM speed control circuit used to receive PWM signals and adjust the current or voltage output to the fan according to the duty cycle of the PWM signals. A PWM amplifier circuit that can amplify the weak signal output by a PWM speed control circuit. DC fan interface circuit for connecting DC fan and PWM amplifier circuit; The main control circuit, PWM speed control circuit, PWM amplifier circuit, and DC fan interface circuit are connected in sequence, and the main control circuit, PWM amplifier circuit, and DC fan interface circuit are all electrically connected to the switching power supply.

2. The fan speed control circuit according to claim 1, characterized in that: The switching power supply includes a power chip U2, a transformer T1, a voltage regulator chip U5, and a voltage regulator chip U6. The power chip U2 is connected to the transformer T1. A diode D16 and a diode D17 are connected between pin 4 of the power chip U2 and pin 5 of the transformer T1. A diode D4 is connected to pin 6 of the transformer T1. A resistor R4 is connected between pin 1 of the voltage regulator chip U5 and diode D4. A resistor R30 is connected between pin 1 of the voltage regulator chip U6 and diode D4.

3. The fan speed control circuit according to claim 2, characterized in that: The terminals of pins 5, 6, 7, and 8 of the power chip U2 are connected to diode D14. One end of diode D14 is connected to resistor R23, resistor R7, and capacitor C8 to form a closed loop. The terminals of resistor R23 and capacitor C8 are connected in sequence to resistor R3, connector CN4, connector CN1, and diode D3. One end of diode D3 is connected to a 220-240V power supply voltage.

4. The fan speed control circuit according to claim 3, characterized in that: The terminals of diodes D16 and D17 are connected to pin 3 of power chip U2 via Zener diodes ZD2 and D15. Furthermore, the terminals of diodes D16 and D17 are connected in parallel with capacitors EC13, C7, EC99, and EC100.

5. The fan speed control circuit according to claim 4, characterized in that: The main control circuit includes a main control chip U1, pin 3 of the voltage regulator chip U5 is connected to pin 12 of the main control chip U1, and the PWM speed control circuit is connected to pin 43 of the voltage regulator chip U5.

6. The fan speed control circuit according to claim 5, characterized in that: The PWM speed control circuit includes a transistor Q2. A resistor R12 and a capacitor C2 are connected in parallel between the base and emitter of the transistor Q2. A resistor R4 is connected to the base of the transistor Q2. One end of the resistor R4 is connected to pin 43 of the voltage regulator chip U5.

7. A fan speed control circuit according to claim 6, characterized in that: The PWM amplifier circuit includes a MOSFET Q3 and a transistor D2. A resistor R26 is connected between the gate and source of the MOSFET Q3. A resistor R25 is also connected to the collector of the transistor Q2 on the gate of the MOSFET Q3. A capacitor EC4, a capacitor C23, an inductor L10 and a diode D4 are connected in parallel between the collector and emitter of the transistor D2. The terminals of the inductor L10 and the diode D4 are connected to the drain of the MOSFET Q3.

8. The fan speed control circuit according to claim 1, characterized in that: The DC fan interface circuit includes a terminal block M1, pin 1 of which is connected to the emitter of transistor D2, and pin 2 of which is connected to the base and collector of transistor D2.

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