Constant-voltage multi-stage fan speed regulating circuit

Abstract

The utility model discloses a constant voltage formula multistage fan speed regulation circuit belongs to the technical field of air cooling radiator, including main control chip U1 and control circuit, and main control chip U1 is the MCU control chip with the DAC function, and control circuit includes chip U2, power module N2 and power module N3, and chip U2 is operational amplifier or operational comparator, and main control chip U1 will voltage signal output to the positive input end of chip U2, and the negative input end of chip U2 is grounded, and the negative input end of chip U2 and the Trim pin of power module N2 are connected respectively to the output end of chip U2, and the output voltage of power module N3 is the power supply of chip U2, and the output voltage of power module N2 is the power supply of fan. The utility model discloses the technical scheme under the condition of not influencing fan multistage speed regulation, realizes the stable voltage value of different amplitude output through the control of power module control end to control fan speed regulation, improves fan service life and stability, and is convenient for later maintenance.

Description

Technical Field

[0001] This utility model belongs to the field of air-cooled heat sink technology, specifically relating to a constant-pressure multi-stage fan speed control circuit. Background Technology

[0002] With the trend of miniaturization and portability of industrial products, air cooling has become widely used, especially in specific working environments where it is necessary to adjust the fan speed at different stages to increase or decrease heat dissipation.

[0003] Fan speed control is mostly used for heat dissipation of key components in equipment. It not only controls the fan speed, but also requires designing different amplitude fan power supply voltages according to the needs to improve the fan's lifespan and the stability of fan speed control.

[0004] Most fan speed controls on the market currently use PWM duty cycle voltage mode. From a microscopic perspective, this means controlling the fan speed by varying the duration of the fan's back-and-forth switching on and off. This places high demands on the fan's performance and significantly reduces its lifespan. Furthermore, the control circuit is not isolated from the fan's power supply, leading to higher maintenance costs. Utility Model Content

[0005] This invention addresses the shortcomings of existing technologies by providing a constant-voltage multi-stage fan speed control circuit. By controlling the power supply module to output stable voltage values ​​of different amplitudes, the fan speed is adjusted, thereby improving the fan's service life and stability, and facilitating future maintenance.

[0006] This utility model achieves this objective through the following technical solution: A constant voltage multi-stage fan speed control circuit includes a main control chip U1 and a control circuit. The main control chip U1 is an MCU control chip with DAC function. The control circuit includes a chip U2, a power module N2, and a power module N3. The chip U2 is an operational amplifier or operational comparator. The main control chip U1 outputs a voltage signal to the positive input terminal of the chip U2. The negative input terminal of the chip U2 is grounded. The output terminal of the chip U2 is connected to the negative input terminal of the chip U2 and the Trim pin of the power module N2. The output voltage of the power module N3 supplies power to the chip U2, and the output voltage of the power module N2 supplies power to the fan.

[0007] Furthermore, both power module N2 and power module N3 output positive voltage and 0V voltage, respectively.

[0008] Furthermore, the 0V voltage output terminal of the power module N2 is connected to the positive input terminal of the chip U2 and the 0V voltage output terminal of the power module N3, respectively.

[0009] Furthermore, series resistors are provided on the connection lines of the positive and negative input terminals of the chip U2, and series resistors are provided on the connection lines between the output terminal and the negative input terminal of the chip U2.

[0010] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. It can achieve precise multi-level speed regulation.

[0011] 2. Outputs a stable DC voltage, improving fan stability.

[0012] 3. It is isolated from the upstream control system, which facilitates later maintenance.

[0013] 4. Extend the lifespan of the fan. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the principle of an embodiment of the present utility model; Figure 2 This is a circuit diagram of the main control chip in an embodiment of the present invention; Figure 3 This is a circuit diagram of the control circuit in an embodiment of the present invention. Detailed Implementation

[0015] Exemplary embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0016] This utility model discloses a constant-pressure multi-stage fan speed control circuit, the principle block diagram of which is shown below. Figure 1 As shown, it includes two parts: the main control chip circuit and the control circuit.

[0017] Main control chip circuit such as Figure 2As shown, the circuit includes control chip U1, which is model GD32F303RET6. The specific circuit is as follows: Pin 60 of chip U1 is connected to DGND through resistor R8; pin 28 of chip U1 is connected to DGND through circuit R2; pins 5 and 6 of chip U1 are connected to DGND through capacitors C5 and C6 respectively, and pin 5 is also connected to pin 6 through an 8MHz crystal oscillator; pin 7 of chip U1 is connected to a +3.3V power supply through resistor R9, and to DGND through capacitor C7, and is also connected to pin 5 of connector J1; pins 1, 13, 19, 32, 48, and 64 of chip U1 are connected to a 3.3V power supply; pins 12 and 18 of chip U1... Pins 31, 47, and 63 are connected to DGND respectively; pin 46 of chip U1 is connected to pin 3 of connector J1; pin 49 of chip U1 is connected to pin 4 of connector J1; pin 21 of chip U1 is connected to resistor R5; pin 2 of connector J1 is connected to +3.3V power supply; pins 2 and 3 of connector J1 are connected through resistor R11; pin 6 of connector J1 is connected to DGND; pins 4 and 6 of connector J1 are connected through resistor R12; the two ends of capacitors C13, C14, C15, C16, C17, and C18 are connected to +3.3V power supply and DGND respectively.

[0018] Control circuit such as Figure 3As shown, it consists of a control circuit including chip U2, power module N2, and power module N3. Chip U2 is LM528, power module N2 is URB4824YMD-30WR3, and power module N3 is WRB2415S-1WR2. The Vin pin of power module N3 is connected to the +28V port power supply; the GND pin of power module N3 is connected to GND; the two ends of capacitors C8 and C9 are connected to the +28V port power supply and GND respectively; the +Vo pin of power module N3 is connected to pin 8 of chip U2A; the 0V pin of power module N3 is connected to pin 4 of chip U2A; the 0V pin of power module N3 is connected to pin 5 of chip U2B through R4; the 0V pin of power module N3 is connected to pin 6 of power module N2; the two ends of capacitors C10, C11, and C12 are connected to the 15V output power supply and FS- of power module N3 respectively; pins 1 and 2 of chip U2A are directly connected; pin 3 of chip U2A... Pin 5 of chip U2B is connected to the 0V pin of N3 via resistor R4, and to pin 21 of chip U1 via resistor R5; pin 6 of chip U2B is connected to pin 7 of chip U2B via resistor R10, and to DGND via resistor R7; pin 7 of chip U2B is connected to pin 5 of power module N2 via resistor R3; pin 3 of power module N2 is connected to the +28V port power supply; pin 1 of power module N2 is connected to GND; pin 4 of power module N2 is connected to FS+; capacitors C3 and C4 are connected to the +28V port power supply and GND respectively; capacitors C1 and C2 are connected to FS+ and FS- of the output fan of power module N3 respectively.

[0019] The 0V pin of power module N3 is connected to pin 4 of chip U2A. The 0V pin of power module N3 is connected to pin 5 of chip U2B through R4. The 0V pin of power module N3 is connected to pin 6 of power module N2, ensuring that the entire circuit is in a common ground condition and ensuring signal stability.

[0020] Pin 5 of chip U2B is connected to pin 21 of main control chip U1 through resistor R5. Multi-level speed regulation of the fan can be achieved by controlling the power control signal issued by control chip U1.

[0021] Pin 5 of chip U2B is connected to the 0V pin of power module N3 through resistor R4. Pin 6 of chip U2B is connected to pin 7 of U2B through resistor R10, and connected to DGND through resistor R7. The output terminal of chip U2B is connected to pin 5 of power module N2. The fan speed can be adjusted and controlled with the precision of chip U2B.

[0022] In this technical solution, the main control chip U1 can be any MCU control chip with DAC function, and the chip U2 can be any operational comparator or operational amplifier such as SGM8302 or AD822.

[0023] The present invention has been described in detail above through embodiments, but the content described is only an exemplary embodiment of the present invention and should not be considered as limiting the scope of implementation of the present invention. The protection scope of the present invention is defined by the claims. Any technical solutions designed by those skilled in the art using the technical solutions described in the present invention, or designed by those skilled in the art under the inspiration of the technical solutions of the present invention, within the substance and protection scope of the present invention, to achieve the above-mentioned technical effects, or equivalent changes and improvements made to the scope of the application, should still fall within the patent protection scope of the present invention. It should be noted that, for clarity, some descriptions of content that are not directly and obviously related to the protection scope of the present invention but are known to those skilled in the art have been omitted in the description of the present invention.

Claims

1. A constant voltage multi-stage fan speed control circuit, characterized in that, The system includes a main control chip U1 and a control circuit. The main control chip U1 is an MCU control chip with DAC function. The control circuit includes a chip U2, a power module N2, and a power module N3. The chip U2 is an operational amplifier or operational comparator. The main control chip U1 outputs a voltage signal to the positive input terminal of the chip U2. The negative input terminal of the chip U2 is grounded. The output terminal of the chip U2 is connected to the negative input terminal of the chip U2 and the Trim pin of the power module N2. The output voltage of the power module N3 supplies power to the chip U2, and the output voltage of the power module N2 supplies power to the fan.

2. The constant voltage multi-stage fan speed control circuit according to claim 1, characterized in that, Both power module N2 and power module N3 output positive voltage and 0V voltage, respectively.

3. The constant voltage multi-stage fan speed control circuit according to claim 2, characterized in that, The 0V voltage output terminal of the power module N2 is connected to the positive input terminal of the chip U2 and the 0V voltage output terminal of the power module N3, respectively.

4. A constant-voltage multi-stage fan speed control circuit according to any one of claims 1 or 3, characterized in that, A series resistor is provided on each of the connection lines of the positive and negative input terminals of the chip U2, and a series resistor is provided on the connection line between the output terminal and the negative input terminal of the chip U2.

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