Fan speed regulation circuit, cooling fan and inverter

Abstract

The utility model discloses a fan rotating speed regulation circuit, heat dissipation fan and inverter. This fan rotating speed regulation circuit includes: duty ratio adjustment module, duty ratio generating module and fan drive module, and the input end of duty ratio adjustment module is connected temperature sampling signal, and temperature sampling signal feature device's temperature, and duty ratio adjustment module is used for after temperature sampling signal exceeds limit threshold, and temperature sampling signal output, and the first input end of duty ratio generating module is electrically connected with the output of duty ratio adjustment module, and receives temperature sampling signal that exceeds limit threshold, and the second input end of duty ratio generating module is connected with the carrier signal of period variation, and duty ratio generating module is used for comparing temperature sampling signal and carrier signal, and the output duty ratio signal, and the input of fan drive module is connected duty ratio signal, and according to duty ratio signal output drive signal, to control the rotating speed of fan. The utility model is favorable for promoting the performance of heat dissipation fan.

Description

Technical Field

[0001] This utility model relates to the field of inverter technology, and in particular to a fan speed regulation circuit, a cooling fan, and an inverter. Background Technology

[0002] Inverters are the core equipment for power conversion, and their performance plays a crucial role in the overall power conversion product. During operation, the power electronic components inside the inverter generate a significant amount of heat due to the high-frequency switching required. Therefore, fans are typically used as cooling devices to dissipate heat from these components. However, cooling fans generate noise during operation, which is particularly noticeable in environments with high noise requirements, such as residential areas or offices, thus affecting the performance of the cooling fans. Utility Model Content

[0003] This invention provides a fan speed regulation circuit, a cooling fan, and an inverter to improve the performance of the cooling fan.

[0004] According to one aspect of the present invention, a fan speed regulation circuit is provided, wherein the fan is used for heat dissipation of a device, and the fan speed regulation circuit includes:

[0005] A duty cycle adjustment module is provided, wherein a temperature sampling signal is connected to the input terminal of the duty cycle adjustment module, the temperature sampling signal representing the temperature of the device; the duty cycle adjustment module is used to output the temperature sampling signal after the temperature sampling signal exceeds a limit threshold.

[0006] A duty cycle generation module, wherein the first input terminal of the duty cycle generation module is electrically connected to the output terminal of the duty cycle adjustment module, and receives the temperature sampling signal exceeding the limit threshold; the second input terminal of the duty cycle generation module is connected to a periodically varying carrier signal; the duty cycle generation module is used to compare the temperature sampling signal and the carrier signal, and output a duty cycle signal.

[0007] A fan drive module is provided, wherein the input terminal of the fan drive module is connected to the duty cycle signal, and the output drive signal is generated according to the duty cycle signal to control the speed of the fan.

[0008] Optionally, the duty cycle adjustment module includes: a first switching device and a first resistor;

[0009] The first terminal of the first switching device is electrically connected to the input terminal of the duty cycle adjustment module, the second terminal of the first switching device is electrically connected to the output terminal of the duty cycle adjustment module, and the control terminal of the first switching device is electrically connected to its first terminal through the first resistor.

[0010] Optionally, the duty cycle adjustment module further includes a second resistor and a first diode. The control terminal of the first switching device is grounded through the second resistor, the anode of the first diode is electrically connected to the control terminal of the first switching device, and the cathode of the first diode is grounded.

[0011] Optionally, the duty cycle adjustment module further includes:

[0012] At least two second diodes are connected in series, with the anode of the second diode electrically connected to the input terminal of the duty cycle adjustment module and the cathode of the second diode electrically connected to the output terminal of the duty cycle adjustment module.

[0013] Optionally, the duty cycle generation module includes:

[0014] A filtering unit, the input terminal of which is electrically connected to the first input terminal of the duty cycle generation module, is used to filter the temperature sampling signal;

[0015] The comparison unit has a first input terminal electrically connected to the output terminal of the filtering unit, and a second input terminal electrically connected to the second input terminal of the duty cycle generation module; the comparison unit is used to compare the temperature sampling signal with the carrier signal and output the duty cycle signal.

[0016] Optionally, the fan drive module includes: a second switching device and a third switching device of opposite types;

[0017] The control terminals of both the second and third switching devices are electrically connected to the input terminal of the fan drive module;

[0018] The first terminal of the second switching device is connected to the first power supply voltage, the second terminal of the second switching device is electrically connected to the first terminal of the third switching device, and the second terminal of the third switching device is grounded.

[0019] The second terminal of the second switching device is electrically connected to the output terminal of the fan drive module.

[0020] Optionally, the number of fan drive modules is at least two; the drive end of each fan drive module is electrically connected to the output end of the duty cycle generation module.

[0021] Optionally, the output of the fan drive module is electrically connected to at least one of the fans.

[0022] According to another aspect of the present invention, a cooling fan is provided, comprising: a fan body and a fan speed adjustment circuit as described in any embodiment of the present invention, wherein the fan speed adjustment circuit is used to adjust the speed of the fan body.

[0023] According to another aspect of the present invention, an inverter is provided, comprising: power electronic devices, a fan, and a fan speed regulation circuit as described in any embodiment of the present invention; the fan is used to dissipate heat from the power electronic devices, and the fan speed regulation circuit is used to regulate the speed of the fan.

[0024] This embodiment of the invention provides a fan speed regulation circuit including a duty cycle regulation module, a duty cycle generation module, and a fan drive module. The input signal of this circuit is a temperature sampling signal, and the output signal is a drive signal to control the fan. This embodiment of the invention improves the performance of the cooling fan, specifically achieving at least the following beneficial effects:

[0025] Firstly, the circuit controls the fan speed through temperature feedback from the device, thus achieving closed-loop control of the fan speed.

[0026] Secondly, the circuit can linearly increase or decrease the duty cycle based on the feedback temperature sampling signal, resulting in smoother speed regulation. Furthermore, the fan speed is also lower when the device temperature is low, which helps to reduce fan noise.

[0027] Thirdly, the circuit has a strong driving capability, and its output terminal can be connected to more fans, thereby reducing the number of circuit output ports (I / O ports);

[0028] Fourthly, the circuit limits the minimum duty cycle of the duty cycle signal, that is, there is a minimum duty cycle when the fan starts, which helps to avoid the fan starting repeatedly when the device temperature is low, thus contributing to the stable operation of the fan.

[0029] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram of a fan speed regulation circuit provided for an embodiment of this utility model;

[0032] Figure 2 A waveform diagram illustrating fan speed regulation is provided for an embodiment of this utility model;

[0033] Figure 3 A schematic diagram of another fan speed regulation circuit provided for an embodiment of this utility model;

[0034] Figure 4 A schematic diagram of another fan speed regulation circuit provided for an embodiment of this utility model;

[0035] Figure 5 A schematic diagram of another fan speed regulation circuit provided for an embodiment of this utility model;

[0036] Figure 6 A schematic diagram of another fan speed regulation circuit provided in an embodiment of this utility model. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention 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 invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0038] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0039] This utility model embodiment provides a fan speed regulation circuit. The fan is used for heat dissipation of a device, wherein the device can be a power electronic device or other device that generates a lot of heat. Figure 1 This is a schematic diagram of a fan speed regulation circuit provided for an embodiment of the present invention. See also... Figure 1 The fan speed regulation circuit includes:

[0040] The duty cycle adjustment module 200 has a temperature sampling signal connected to its input terminal. The temperature sampling signal represents the temperature of the device. The duty cycle adjustment module 200 is used to output the temperature sampling signal after the temperature sampling signal exceeds the limit threshold.

[0041] The duty cycle generation module 300 has its first input terminal electrically connected to the output terminal of the duty cycle adjustment module 200, and receives a temperature sampling signal exceeding a limit threshold; its second input terminal is connected to a periodically changing carrier signal; the duty cycle generation module 300 is used to compare the temperature sampling signal and the carrier signal, and output a duty cycle signal.

[0042] The fan drive module 400 has a duty cycle signal input terminal and outputs a drive signal based on the duty cycle signal to control the fan speed.

[0043] Figure 2 A waveform diagram illustrating fan speed regulation is provided for an embodiment of this utility model. See also... Figure 2 The horizontal axis represents temperature, and the vertical axis represents duty cycle. The working principle of this fan speed regulation circuit is as follows: When the device temperature is low, the temperature sampling signal is less than the first temperature T1 (i.e., the limit threshold), and the duty cycle regulation module 200 blocks the temperature sampling signal. At this time, the duty cycle regulation module 200 has no output, and correspondingly, the fan drive module 400 outputs a duty cycle signal with a duty cycle of 0. When the device temperature is high, the temperature sampling signal is greater than the first temperature T1 (i.e., the limit threshold), and the duty cycle regulation module 200 outputs the temperature sampling signal. This temperature sampling signal and the carrier signal are simultaneously input to the duty cycle generation module 300. The duty cycle generation module 300 compares the temperature sampling signal and the carrier signal; the larger the temperature sampling signal, the larger the duty cycle of the generated duty cycle signal. For example, when the temperature sampling signal is T2, the duty cycle generation module 300 outputs a duty cycle signal with a duty cycle of Duty2; when the temperature sampling signal is Tmax, the duty cycle generation module 300 outputs a duty cycle signal with a duty cycle of 100% Duty. The fan drive module 400 can generate a drive signal with a corresponding duty cycle based on the duty cycle signal, and the drive capability of the drive signal is greater than that of the duty cycle signal.

[0044] This embodiment of the invention provides a fan speed regulation circuit including a duty cycle regulation module 200, a duty cycle generation module 300, and a fan drive module 400. The input signal of this circuit is a temperature sampling signal, and the output signal is a drive signal to control the fan. This embodiment of the invention improves the performance of the cooling fan, and specifically achieves at least the following beneficial effects:

[0045] Firstly, the circuit controls the fan speed through temperature feedback from the device, thus achieving closed-loop control of the fan speed.

[0046] Secondly, the circuit can linearly increase or decrease the duty cycle based on the feedback temperature sampling signal, resulting in smoother speed regulation. Furthermore, the fan speed is also lower when the device temperature is low, which helps to reduce fan noise.

[0047] Thirdly, the circuit has a strong driving capability, and its output terminal can be connected to more fans, thereby reducing the number of circuit output ports (I / O ports);

[0048] Fourthly, the circuit limits the minimum duty cycle of the duty cycle signal, that is, there is a minimum duty cycle when the fan starts, which helps to avoid the fan starting repeatedly when the device temperature is low, thus contributing to the stable operation of the fan.

[0049] See also Figure 1 Based on the above embodiments, optionally, the duty cycle adjustment module 200 includes: a first switching device Q1 and a first resistor R1. A first terminal of the first switching device Q1 is electrically connected to the input terminal of the duty cycle adjustment module 200, a second terminal of the first switching device Q1 is electrically connected to the output terminal of the duty cycle adjustment module 200, and a control terminal of the first switching device Q1 is electrically connected to its first terminal through the first resistor R1. The first resistor R1 provides a bias voltage to the first switching device Q1 through a temperature sampling signal. When the voltage of the temperature sampling signal reaches the turn-on voltage of the first switching device Q1, the first switching device Q1 is turned on. The turn-on voltage of the first switching device Q1 is a limiting threshold of the duty cycle adjustment module 200.

[0050] For example, the duty cycle adjustment module 200 operates as follows: when the temperature sampling signal is lower than the turn-on voltage of the first switching device Q1, the first switching device Q1 is in the off state; when the temperature sampling signal is higher than the turn-on voltage of the first switching device Q1, the first switching device Q1 can be turned on, outputting the temperature sampling signal exceeding the limit threshold, and then driving the fan to start through the subsequent duty cycle generation module 300 and the fan drive module 400. When the first switching device Q1 is turned on, even if the voltage of the temperature sampling signal is slightly lower than the turn-on voltage of the first switching device Q1, the first switching device Q1 can still remain on. Therefore, the problem of repeated start-stop of the fan near the limit threshold can be avoided, improving the stability of fan operation.

[0051] Based on the above embodiments, the first switching device Q1 may optionally be a transistor or a MOSFET, which can be set as needed in practical applications.

[0052] See also Figure 1Based on the above embodiments, optionally, the duty cycle adjustment module 200 further includes a second resistor R2 and a first diode D1. The control terminal of the first switching device Q1 is grounded through the second resistor R2. The anode of the first diode D1 is electrically connected to the control terminal of the first switching device Q1, and the cathode of the first diode D1 is grounded. The first resistor R1 and the second resistor R2 divide the temperature sampling signal, limiting the voltage at the control terminal of the first switching device Q1, thus facilitating the stable operation of the first switching device Q1. Furthermore, when the voltage at the control terminal of the first switching device Q1 exceeds the turn-on voltage of the first diode D1, the first diode D1 conducts, clamping the voltage at the control terminal of the first switching device Q1 to the turn-on voltage of the first diode D1, thereby preventing the voltage at the control terminal of the first switching device Q1 from becoming too high.

[0053] Figure 3 A schematic diagram of another fan speed regulation circuit provided in an embodiment of this utility model. See also Figure 3 Based on the above embodiments, optionally, the duty cycle adjustment module 200 further includes at least two second diodes connected in series. The anodes of the second diodes are electrically connected to the input terminal of the duty cycle adjustment module, and the cathodes of the second diodes are electrically connected to the output terminal of the duty cycle adjustment module. For example, there are three second diodes: second diode D2, second diode D3, and second diode D4. The forward voltage drop of the second diodes is U11, and the forward voltage drop of the three second diodes is 3*U11. The three second diodes are connected in parallel with the first switching device Q1. When the first switching device Q1 fails and is not conducting, if the temperature sampling signal reaches the sum of the forward voltages of the second diodes (e.g., 3*U11), the temperature sampling signal is output through the series-connected second diodes, with the limiting threshold being the sum of the forward voltages of the second diodes. Therefore, this embodiment of the invention can achieve a minimum duty cycle limiting effect through each second diode, serving as a backup circuit for the first switching device Q1, thereby improving circuit stability.

[0054] It should be noted that the number of second diodes can be adjusted as needed, but the sum of the forward voltages of each second diode should be greater than or equal to the start-up voltage of the first switching device Q1, so as to prevent each second diode from turning on before the first switching device Q1 turns on when the first switching device Q1 is not faulty.

[0055] See also Figure 3Based on the above embodiments, optionally, the duty cycle generation module 300 includes: a filtering unit 310 and a comparison unit 320. The input terminal of the filtering unit 310 is electrically connected to the first input terminal of the duty cycle generation module 300, and the filtering unit 310 is used to filter the temperature sampling signal. The first input terminal of the comparison unit 320 is electrically connected to the output terminal of the filtering unit 310, and the second input terminal of the comparison unit 320 is electrically connected to the second input terminal of the duty cycle generation module 300. The comparison unit 320 is used to compare the temperature sampling signal with the carrier signal and output a duty cycle signal.

[0056] The filtering unit 310 can adjust the slope of the temperature sampling signal to adjust the duty cycle response rate. For example, if the slope of the temperature sampling signal is larger, the duty cycle response rate is faster; if the slope of the temperature sampling signal is smaller, the duty cycle response rate is slower.

[0057] See also Figure 3 Based on the above embodiments, optionally, the filter unit 310 includes a third resistor R3 and a first capacitor C1; the third resistor R3 is connected between the input and output terminals of the filter unit 310, the first terminal of the first capacitor C1 is electrically connected to the output terminal of the filter unit 310, and the second terminal of the first capacitor C1 is grounded. The filter unit 310 employs an RC filter circuit. By adjusting the values ​​of the third resistor R3 and the first capacitor C1, the slope of the temperature sampling signal can be adjusted. This configuration results in a simple circuit structure that is easy to implement.

[0058] See also Figure 3Based on the above embodiments, optionally, the comparison unit 320 includes a fourth resistor R4, a comparator U1, and a fifth resistor R5; the first input terminal of the comparator U1 is electrically connected to the first input terminal of the comparison unit 320, the second input terminal of the comparator U1 is electrically connected to the second input terminal of the comparator 320, and the output terminal of the comparator U1 is electrically connected to the output terminal of the comparator 320; the power supply terminal of the comparator U1 is connected to a first power supply voltage V1, and the ground terminal of the comparator U1 is grounded; the first terminal of the fourth resistor R4 is electrically connected to the first input terminal of the comparator U1, and the second terminal of the fourth resistor R4 is grounded; the first terminal of the fifth resistor R5 is electrically connected to the output terminal of the comparator U1, and the second terminal of the fifth resistor R5 is grounded. For example, when the temperature sampling signal input to the comparator U1 is greater than the carrier signal, the comparator U1 outputs a high level; when the temperature sampling signal input to the comparator U1 is less than the carrier signal, the comparator U1 outputs a low level. The carrier signal is a periodically changing signal whose voltage gradually increases or decreases. If the voltage of the temperature sampling signal is high, the carrier signal remains lower than the temperature sampling signal for a longer period, resulting in a longer high-level output time. Conversely, if the voltage of the temperature sampling signal is low, the carrier signal remains lower than the temperature sampling signal for a shorter period, resulting in a shorter high-level output time, thus achieving duty cycle adjustment. Furthermore, comparator U1 is connected to the first power supply voltage V1 and has strong driving capability, enabling it to drive a large number of fans.

[0059] See also Figure 3 Based on the above embodiments, optionally, the fan drive module 400 includes: a second switching device Q2 and a third switching device Q3 of opposite types; the control terminals of both the second switching device Q2 and the third switching device Q3 are electrically connected to the input terminal of the fan drive module 400; the first terminal of the second switching device Q2 is connected to a first power supply voltage V2, the second terminal of the second switching device Q2 is electrically connected to the first terminal of the third switching device Q3, and the second terminal of the third switching device Q3 is grounded; the second terminal of the second switching device Q2 is electrically connected to the output terminal of the fan drive module 400. The second switching device Q2 and the third switching device Q3 constitute a push-pull circuit. Specifically, when the second switching device Q2 is turned on, the output terminal of the fan drive module 400 outputs the first power supply voltage V2; when the third switching device Q3 is turned on, the output terminal of the fan drive module 400 outputs a ground voltage. Therefore, the fan drive module 400 outputs a drive signal with varying high and low levels. The high-level voltage is provided by the first power supply voltage V2, which is beneficial for improving the driving capability and driving a larger number of fans.

[0060] Optionally, the second switch Q2 and the third switch Q3 can be transistors or MOSFETs, which can be specified as needed in practical applications.

[0061] Figure 4A schematic diagram of another fan speed regulation circuit provided in an embodiment of this utility model. See also Figure 4 Based on the above embodiments, optionally, the output terminal of the fan drive module 400 is electrically connected to at least one fan. The fan drive module 400 has strong driving capability, and this configuration helps to reduce the number of circuit output ports.

[0062] Figure 5 A schematic diagram of another fan speed regulation circuit provided in an embodiment of this utility model. See also Figure 5 Based on the above embodiments, optionally, the number of fan drive modules 400 is at least two; the drive terminal of each fan drive module 400 is electrically connected to the output terminal of the duty cycle generation module 300. The comparator U1 has strong driving capability, and this arrangement helps to reduce the number of circuit output ports.

[0063] Figure 6 A schematic diagram of another fan speed regulation circuit provided in an embodiment of this utility model. See also Figure 6 Optionally, based on the above embodiments, the fan speed adjustment circuit further includes a sampling module 100, which includes a sixth resistor R6 and a seventh resistor R7. The first end of the sixth resistor R6 is connected to the second power supply voltage V1, the second end of the sixth resistor R6 is electrically connected to the first end of the seventh resistor R7, the second end of the seventh resistor R7 is grounded, and the second end of the sixth resistor R6 is connected to the temperature sampling signal.

[0064] In the above embodiments, the carrier signal can be a triangular wave, a sawtooth wave, or a sine wave, etc. Among them, using a triangular wave or a sawtooth wave as the carrier signal is beneficial for linear adjustment of the duty cycle, while using a sine wave as the carrier signal makes the duty cycle non-linearly adjustable.

[0065] In the above embodiments, the carrier signal can be generated by a dedicated chip, a digital signal processing chip, or a hardware generation circuit.

[0066] See also Figure 6In one embodiment, the fan speed regulation circuit may optionally include a carrier signal generation module 500. Optionally, the carrier signal generation module 500 is an oscillation circuit capable of generating a triangular wave. Exemplarily, the carrier signal generation module 500 includes a first operational amplifier U2, a second operational amplifier U3, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, and a second capacitor C2. The first input terminal of the first operational amplifier U2 is grounded. The second input terminal of the first operational amplifier U2 is electrically connected to the first terminal of the ninth resistor R9, and also electrically connected to the first terminal of the tenth resistor R10. The output terminal of the first operational amplifier U2 is connected to the first input terminal of the second operational amplifier U3 through the eighth resistor R8 and the eleventh resistor R11. The second terminal of the ninth resistor R9 is connected between the eighth resistor R8 and the eleventh resistor R11. The second terminal of the tenth resistor R10 is electrically connected to the output terminal of the second operational amplifier U2. The second input terminal of the second operational amplifier U3 is grounded through the twelfth resistor. The first terminal of the second capacitor C2 is electrically connected to the first input terminal of the second operational amplifier, and the second terminal of the second capacitor C2 is electrically connected to the output terminal of the second operational amplifier U3. This carrier signal generation module 500 uses operational amplifiers to achieve multivibrator operation and generate a triangular wave.

[0067] This utility model embodiment also provides a cooling fan, which includes: a fan body and a fan speed adjustment circuit as provided in any embodiment of this utility model, the fan speed adjustment circuit being used to adjust the speed of the fan body. This cooling fan possesses the corresponding beneficial effects of the fan speed adjustment circuit, which will not be elaborated further.

[0068] This utility model embodiment also provides an inverter, which includes: power electronic devices, a fan, and a fan speed regulation circuit as provided in any embodiment of this utility model; the fan is used to dissipate heat from the power electronic devices, and the fan speed regulation circuit is used to regulate the fan speed. This inverter possesses the corresponding beneficial effects of the fan speed regulation circuit, which will not be elaborated further.

[0069] It should be understood that the various forms of the process shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this utility model can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this utility model can be achieved, and this is not limited herein.

[0070] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A fan speed regulation circuit, characterized in that, The fan is used for heat dissipation of the device, and the fan speed regulation circuit includes: A duty cycle adjustment module is provided, wherein a temperature sampling signal is connected to the input terminal of the duty cycle adjustment module, the temperature sampling signal representing the temperature of the device; the duty cycle adjustment module is used to output the temperature sampling signal after the temperature sampling signal exceeds a limit threshold. A duty cycle generation module, wherein the first input terminal of the duty cycle generation module is electrically connected to the output terminal of the duty cycle adjustment module, and receives the temperature sampling signal exceeding the limit threshold; the second input terminal of the duty cycle generation module is connected to a periodically varying carrier signal; the duty cycle generation module is used to compare the temperature sampling signal and the carrier signal, and output a duty cycle signal. A fan drive module is provided, wherein the input terminal of the fan drive module is connected to the duty cycle signal, and the output drive signal is generated according to the duty cycle signal to control the speed of the fan.

2. The fan speed regulation circuit according to claim 1, characterized in that, The duty cycle adjustment module includes: a first switching device and a first resistor; The first terminal of the first switching device is electrically connected to the input terminal of the duty cycle adjustment module, the second terminal of the first switching device is electrically connected to the output terminal of the duty cycle adjustment module, and the control terminal of the first switching device is electrically connected to its first terminal through the first resistor.

3. The fan speed regulation circuit according to claim 2, characterized in that, The duty cycle adjustment module further includes a second resistor and a first diode. The control terminal of the first switching device is grounded through the second resistor. The anode of the first diode is electrically connected to the control terminal of the first switching device, and the cathode of the first diode is grounded.

4. The fan speed regulation circuit according to claim 2, characterized in that, The duty cycle adjustment module also includes: At least two second diodes are connected in series, with the anode of the second diode electrically connected to the input terminal of the duty cycle adjustment module and the cathode of the second diode electrically connected to the output terminal of the duty cycle adjustment module.

5. The fan speed regulation circuit according to claim 1, characterized in that, The duty cycle generation module includes: A filtering unit, the input terminal of which is electrically connected to the first input terminal of the duty cycle generation module, is used to filter the temperature sampling signal; The comparison unit has a first input terminal electrically connected to the output terminal of the filtering unit, and a second input terminal electrically connected to the second input terminal of the duty cycle generation module; the comparison unit is used to compare the temperature sampling signal with the carrier signal and output the duty cycle signal.

6. The fan speed regulation circuit according to claim 1, characterized in that, The fan drive module includes: a second switching device and a third switching device of opposite types; The control terminals of both the second and third switching devices are electrically connected to the input terminal of the fan drive module; The first terminal of the second switching device is connected to the first power supply voltage, the second terminal of the second switching device is electrically connected to the first terminal of the third switching device, and the second terminal of the third switching device is grounded. The second terminal of the second switching device is electrically connected to the output terminal of the fan drive module.

7. The fan speed regulation circuit according to claim 1, characterized in that, The number of fan drive modules is at least two; the drive end of each fan drive module is electrically connected to the output end of the duty cycle generation module.

8. The fan speed regulating circuit according to any one of claims 1-7, characterized in that, The output terminal of the fan drive module is electrically connected to at least one of the fans.

9. A cooling fan, characterized in that, include: The fan body and the fan speed adjustment circuit as described in any one of claims 1-8, wherein the fan speed adjustment circuit is used to adjust the speed of the fan body.

10. An inverter, characterized in that, include: Power electronic devices, fans, and fan speed regulation circuits as described in any one of claims 1-8; The fan is used to dissipate heat from the power electronic device, and the fan speed regulation circuit is used to regulate the fan speed.

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