Driving circuit of cooling fan and frequency converter

Abstract

The invention provides a driving circuit of a cooling fan and a frequency converter, and relates to the technical field of integrated circuits, the driving circuit of the cooling fan adopts a switch module formed by connecting a plurality of paths of triodes serving as switch tubes in parallel, on one hand, the defect that the current of the triodes is small can be overcome, and compared with MOS tubes with higher cost serving as the switch tubes, the driving circuit of the cooling fan has the advantages that the cost is reduced; the cost can be reduced; and on the other hand, when one switch unit is abnormal, a plurality of switch modules formed by connecting triodes serving as switch tubes in parallel can also play a redundant role, so that the reliability of the driving circuit of the cooling fan is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuits, and more particularly to a driving circuit and a frequency converter for a heat dissipation fan. Background Art

[0002] With the development of inverter technology, it has gradually been applied to the field of high-speed drive to achieve high-speed motor drive control. Therefore, the reliability requirements for inverters at high switching frequencies are becoming increasingly higher.

[0003] The cooling fan is one of the main components for the reliable and stable operation of the inverter. Therefore, how to improve the reliability of the driving circuit of the cooling fan is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0004] In view of this, in order to solve the above problems, the present invention provides a driving circuit and inverter for a cooling fan, and the technical solution is as follows:

[0005] A driving circuit for a heat dissipation fan, comprising: a driving module and a switch module;

[0006] The first end of the driving module is electrically connected to the cooling fan control signal output end, the second end is electrically connected to the first voltage end, the third end is electrically connected to the first end of the switch module, and the fourth end is grounded;

[0007] The second end of the switch module is electrically connected to the second voltage end, the third end of the switch module is electrically connected to the first end of the cooling fan, and the second end of the cooling fan is grounded;

[0008] The switch module includes at least two switch units connected in parallel, and the switch unit includes at least a transistor, the emitter of the transistor is electrically connected to the second voltage end, the collector of the transistor is electrically connected to the first end of the cooling fan, and the base of the transistor is electrically connected to the second voltage end and the third end of the driving module respectively;

[0009] The driving module is used to control the working state of the switch module according to the control signal output by the cooling fan control signal output terminal.

[0010] The heat dissipation fan driving circuit provided by the present invention adopts a switch module composed of multiple transistors connected in parallel as switching tubes. On the one hand, it can overcome the disadvantage of the low current of the transistor itself and reduce costs compared with the more expensive MOS tubes used as switching tubes. On the other hand, when an abnormality occurs in one of the switch units, the switch module composed of multiple transistors connected in parallel as switching tubes can also play a redundant role, thereby ensuring the reliability of the heat dissipation fan driving circuit.

[0011] Preferably, in order to effectively apply current to the base of the transistor in the switch unit, in the above-mentioned driving circuit of the heat dissipation fan, the switch unit further includes: a first resistor;

[0012] The base of the transistor is electrically connected to the second voltage terminal through the first resistor.

[0013] Preferably, in order to ensure that the third terminal of the driving module is not impacted by an excessive current, in the driving circuit of the cooling fan, the switch unit further comprises: a current limiting protection subunit;

[0014] The base of the transistor is electrically connected to the third terminal of the driving module through the current limiting protection subunit.

[0015] Preferably, in order to ensure that the third terminal of the driving module is not impacted by an excessive current and to not increase the complexity of the circuit, in the driving circuit of the cooling fan, the current limiting protection subunit is a second resistor;

[0016] One end of the second resistor is electrically connected to the base of the transistor, and the other end of the second resistor is electrically connected to the third end of the driving module.

[0017] Preferably, in order to avoid the problem of damage to the drive control circuit inside the inverter when the cooling fan is abnormally blocked, in the driving circuit of the cooling fan, the switch unit further includes: an overcurrent protection subunit;

[0018] The collector of the transistor is electrically connected to the first end of the cooling fan through the overcurrent protection subunit;

[0019] The overcurrent protection subunit is configured to be in an off state when the current flowing through it is greater than or equal to a preset current, and to be in an on state when the current flowing through it is less than the preset current.

[0020] Preferably, in order to simplify the complexity of the overcurrent protection device in the prior art, in the driving circuit of the cooling fan, the overcurrent protection subunit is a self-resetting fuse;

[0021] One end of the self-recovery fuse is electrically connected to the collector of the transistor, and the other end is electrically connected to the first end of the cooling fan.

[0022] Preferably, in order to effectively prevent the electromotive force generated when the cooling fan stops from damaging the cooling fan and its driving circuit, a discharge path is provided for the electromotive force generated when the cooling fan stops. In the above-mentioned driving circuit of the cooling fan, the driving circuit of the cooling fan further includes: a Schottky diode;

[0023] The cathode of the Schottky diode is electrically connected to the first end of the heat dissipation fan, and the anode of the Schottky diode is electrically connected to the second end of the heat dissipation fan.

[0024] Preferably, in order to achieve electrical isolation of the driving circuit of the cooling fan, avoid interference with the weak current control circuit, and ensure reliable and stable control of the cooling fan, in the driving circuit of the cooling fan, the driving module includes an isolation device.

[0025] Preferably, in order to protect the isolation device, in the above-mentioned driving circuit of the heat dissipation fan, the driving module further includes: a third resistor and a fourth resistor;

[0026] The first end of the third resistor is electrically connected to the cooling fan control signal output end, and the second end of the third resistor and the first end of the fourth resistor are both electrically connected to the first end of the isolation device;

[0027] The second end of the fourth resistor is electrically connected to the first voltage end and the second end of the isolation device respectively.

[0028] The present application also provides an inverter, which includes a cooling fan and a driving circuit of the cooling fan described in any one of the above items. The inverter has the same technical effect as the driving circuit of the cooling fan.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The heat dissipation fan driving circuit provided by the present invention adopts a switch module composed of multiple transistors connected in parallel as switching tubes. On the one hand, it can overcome the disadvantage of the low current of the transistor itself and reduce costs compared with the more expensive MOS tubes used as switching tubes. On the other hand, when an abnormality occurs in one of the switch units, the switch module composed of multiple transistors connected in parallel as switching tubes can also play a redundant role, thereby ensuring the reliability of the heat dissipation fan driving circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0032] Figure 1 A schematic diagram of the circuit structure of a driving circuit for a heat dissipation fan provided by an embodiment of the present invention;

[0033] Figure 2A schematic diagram of the circuit structure of another driving circuit for a heat dissipation fan provided by an embodiment of the present invention;

[0034] Figure 3 A schematic diagram of the circuit structure of another driving circuit for a heat dissipation fan provided by an embodiment of the present invention;

[0035] Figure 4 A schematic diagram of the circuit structure of another driving circuit for a heat dissipation fan provided by an embodiment of the present invention;

[0036] Figure 5 A schematic diagram of the circuit structure of another driving circuit for a heat dissipation fan provided by an embodiment of the present invention;

[0037] Figure 6 A schematic diagram of the circuit structure of another driving circuit for a heat dissipation fan provided by an embodiment of the present invention;

[0038] Figure 7 A schematic diagram of the circuit structure of another driving circuit for a heat dissipation fan provided by an embodiment of the present invention;

[0039] Figure 8 A schematic diagram of the circuit structure of another driving circuit for a heat dissipation fan provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] Based on the background information, the cooling fan's environment may be subject to high dust and humidity, and is therefore classified as a vulnerable part of the inverter. Generally, the cooling fan is replaced regularly to ensure inverter reliability. However, even with regular replacement, there are still various situations where the cooling fan may become blocked due to prolonged exposure to dusty environments. This can damage the inverter's internal control circuitry, leading to the inverter shutting down due to over-temperature protection, and affecting the inverter's reliable and stable operation.

[0042] Based on this, an embodiment of the present invention provides a driving circuit and inverter for a cooling fan, which can solve the technical problems existing in the prior art. In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0043] refer to Figure 1 , Figure 1 1 is a schematic diagram of a circuit structure of a driving circuit of a heat dissipation fan provided by an embodiment of the present invention. The driving circuit of a heat dissipation fan provided by an embodiment of the present invention includes: a driving module 10 and a switch module 11 .

[0044] The first terminal A1 of the driving module 10 is electrically connected to the cooling fan control signal output terminal FAN, the second terminal A2 is electrically connected to the first voltage terminal VCC1, the third terminal A3 is electrically connected to the first terminal B1 of the switch module 11, and the fourth terminal A4 is grounded GND.

[0045] The second end B2 of the switch module 11 is electrically connected to the second voltage end VCC2 , the third end B3 of the switch module 11 is electrically connected to the first end C1 of the cooling fan 12 , and the second end C2 of the cooling fan 12 is grounded.

[0046] In which, the switching module 11 includes at least two switching units 13 connected in parallel, and the switching unit 13 includes at least a transistor Q, the emitter of the transistor Q is electrically connected to the second voltage terminal VCC2, the collector of the transistor Q is electrically connected to the first end C1 of the cooling fan 12, and the base of the transistor Q is electrically connected to the second voltage terminal VCC2 and the third end A3 of the driving module 10 respectively.

[0047] The driver module 10 is used to control the operating state of the switch module 11 based on the control signal output by the cooling fan control signal output terminal FAN. Specifically, under normal circumstances, after the inverter is powered on, when the temperature inside the inverter cabinet reaches a certain temperature threshold t_th, for example, 40°C, the DSP main control chip sends an operating signal for the cooling fan 12 from the cooling fan control signal output terminal FAN. The operating signal drives the subsequent switch module 11 after passing through the driver module 10. The subsequent switch module 11 uses multiple transistors Q connected in parallel as switching tubes. Driven by the driver module 10, the switch module 11 realizes the opening of the power supply of the cooling fan 12. For example, the second voltage terminal VCC2 can provide a voltage of 24V, thereby operating the cooling fan 12.

[0048] Specifically, in the embodiment of the present invention, the switch module 11 includes two switch units 13 as an example for description. In some optional embodiments, the switch module 11 may also include more than two switch units 13. In the embodiment of the present invention, the specific number of switch units 13 included in the switch module 11 is not limited. It is sufficient to ensure that the switch module 11 includes at least two switch units 13 connected in parallel. The voltage of the first voltage terminal VCC1 can be adapted to the operating voltage of the driver module 10, and the voltage of the second voltage terminal VCC2 can be adapted to the operating voltage of the cooling fan 12. For example, the voltage output by the second voltage terminal VCC2 can be 24V.

[0049] As can be seen from the above description, since the current of the triode as a switching tube is relatively small, some solutions in the prior art will choose a MOS tube with larger current and higher cost as the switching tube. In the embodiment of the present application, a switch module 11 composed of multiple triodes Q connected in parallel as the switching tube can overcome the disadvantage of the small current of the triode Q itself and reduce the cost compared with the more expensive MOS tube as the switching tube. On the other hand, when an abnormality occurs in one of the switch units 13, the switch module 11 composed of multiple triodes Q connected in parallel as the switching tube can also play a redundant role, thereby ensuring the reliability of the driving circuit of the cooling fan 12.

[0050] Optionally, in another embodiment of the present invention, as Figure 1 As shown, the switch unit 13 further includes: a first resistor R1.

[0051] The base of the transistor Q is electrically connected to the second voltage terminal VCC2 through the first resistor R1.

[0052] Specifically, in this embodiment, in order to effectively apply current to the base of the transistor Q in the switch unit 13 , a first resistor R1 may be provided between the second voltage terminal VCC2 and the base of the transistor Q.

[0053] Optionally, in another embodiment of the present invention, referring to Figure 2 , Figure 2 A schematic diagram of the circuit structure of another cooling fan driving circuit provided by an embodiment of the present invention is provided. Figure 3 , Figure 3 This is a circuit structure diagram of another heat dissipation fan driving circuit provided by an embodiment of the present invention. In the heat dissipation fan driving circuit provided by an embodiment of the present invention, the switch unit 13 further includes: a current limiting protection subunit 14.

[0054] The base of the transistor Q is electrically connected to the third terminal A3 of the driving module 10 through the current limiting protection subunit 14 .

[0055] like Figure 3 As shown, the current limiting protection subunit 14 can be a second resistor R2.

[0056] One end of the second resistor R2 is electrically connected to the base of the transistor Q, and the other end is electrically connected to the third end A3 of the driving module.

[0057] Specifically, in this embodiment of the present invention, to protect the third terminal A3 of the driver module 10 from excessive current, a second resistor R2 is added between the base of the transistor Q and the third terminal A3 of the driver module 10 as a current-limiting protection subunit 14. This provides current protection for the driver module 10 and further improves the reliability of the cooling fan's drive circuit. Furthermore, to simplify the complexity of conventional current-limiting protection circuits, this embodiment of the present invention employs the second resistor R2 as the current-limiting protection subunit 14.

[0058] Optionally, in another embodiment of the present invention, referring to Figure 4 , Figure 4 A schematic diagram of a circuit structure of a driving circuit of another cooling fan provided by an embodiment of the present invention is shown in FIG. Figure 5 , Figure 5 This is a circuit structure diagram of another heat dissipation fan driving circuit provided by an embodiment of the present invention. In the heat dissipation fan driving circuit provided by the embodiment of the present invention, the switch unit 13 further includes: an overcurrent protection subunit 15.

[0059] The collector of the transistor Q is electrically connected to the first end C1 of the cooling fan 12 through the overcurrent protection subunit 15 .

[0060] The overcurrent protection subunit 15 is configured to be in an off state when the current flowing through it is greater than or equal to a preset current, and to be in an on state when the current flowing through it is less than the preset current.

[0061] like Figure 5 As shown, the overcurrent protection subunit 15 is a self-recovery fuse F1.

[0062] One end of the resettable fuse F1 is electrically connected to the collector of the transistor Q, and the other end is electrically connected to the first end C1 of the cooling fan 12 .

[0063] Specifically, in the embodiment of the present invention, the drive circuit of the cooling fan not only achieves reliable drive but also has certain protection functions. When the cooling fan 12 is overcurrent due to a stall or other reasons, if the cooling fan 12 is not shut down quickly, the large current generated will damage the internal components of the drive circuit. In the present application, when the cooling fan 12 overcurrent occurs, the self-resetting fuse F1 connected in series with the drive circuit will automatically fuse to disconnect the drive circuit of the cooling fan 12, causing the cooling fan 12 to stop running. This will cause the internal temperature of the inverter to rise, and the inverter will eventually shut down due to overtemperature protection, waiting for inspection and replacement of the cooling fan 12. This avoids the problem of damage to the internal drive control circuit of the inverter when the cooling fan 12 stalls abnormally.

[0064] Furthermore, the technical solution of the present application replaces the complex overcurrent protection circuit by connecting a recoverable fuse F1 in series in each switch unit 13, which is simpler and more reliable in terms of overcurrent protection.

[0065] Optionally, in another embodiment of the present invention, referring to Figure 6 , Figure 6 This is a schematic diagram of the circuit structure of another driving circuit of a heat dissipation fan provided by an embodiment of the present invention. The driving circuit of the heat dissipation fan further includes a Schottky diode D1.

[0066] A cathode of the Schottky diode D1 is electrically connected to a first end C1 of the heat dissipation fan 12 , and an anode of the Schottky diode D1 is electrically connected to a second end C2 of the heat dissipation fan 12 .

[0067] Specifically, in the embodiment of the present invention, a Schottky diode D1 is connected in parallel at both ends of the driving power supply of the cooling fan 12, which can effectively prevent the electromotive force generated when the cooling fan 12 stops from damaging the cooling fan 12 and its driving circuit, and provide a discharge path for the electromotive force generated when the cooling fan 12 stops, so as to further improve the reliability of the driving circuit of the cooling fan.

[0068] Optionally, in another embodiment of the present invention, referring to Figure 7 , Figure 7 This is a circuit structure diagram of another driving circuit of a heat dissipation fan provided by an embodiment of the present invention. The driving module 10 provided by the embodiment of the present invention includes an isolation device U1.

[0069] Specifically, in the embodiment of the present invention, the drive circuit of the cooling fan adopts the isolation device U1 to achieve electrical isolation of the drive circuit of the cooling fan, avoid interference with the weak current control circuit, and ensure reliable and stable control of the cooling fan.

[0070] Exemplarily, the isolation device U1 may include other isolation devices such as a magnetic isolation device or an optical coupling isolation device. In the embodiment of the present invention, only the optical coupling isolation device is used as an example for description.

[0071] Optionally, in another embodiment of the present invention, referring to Figure 8 , Figure 8 This is a circuit structure diagram of another driving circuit of a heat dissipation fan provided by an embodiment of the present invention. The driving module 10 further includes: a third resistor R3 and a fourth resistor R4.

[0072] A first end of the third resistor R3 is electrically connected to the cooling fan control signal output terminal FAN, and a second end of the third resistor R3 and a first end of the fourth resistor R4 are both electrically connected to a first end of the isolation device U1 .

[0073] The second end of the fourth resistor R4 is electrically connected to the first voltage terminal VCC1 and the second end of the isolation device U1 respectively.

[0074] Specifically, when the isolation device U1 is an optocoupler isolation device, the optocoupler isolation device includes a diode D2 located on the primary side, with the anode of the diode D2 serving as the first primary terminal and the cathode of the diode D2 serving as the second primary terminal. Under normal circumstances, after the inverter is powered on, when the temperature inside the inverter cabinet reaches a certain temperature threshold t_th, for example, 40°C, the DSP main control chip sends an operation signal for the cooling fan 12 from the cooling fan control signal output terminal FAN. The signal is isolated by the optocoupler isolation device and drives the subsequent switch module 11. The subsequent switch module 11 can optionally be constructed using multiple parallel-connected transistors Q as switching tubes. In the embodiment of the present invention, two paths are used, and each path is connected in series with a resettable fuse F1. Driven by the optocoupler isolation device, the switch module 11 turns on the power supply of the cooling fan 12. For example, the second voltage terminal VCC2 can provide a 24V voltage, thereby operating the cooling fan 12. Specifically, when the DSP main control chip sends a low-level signal (grounded) to activate cooling fan 12, diode D2 on the primary side of the optocoupler isolator is illuminated, and current flows from the first voltage terminal VCC1 of the optocoupler isolator through diode D2 and third resistor R3 back to the power ground. Third resistor R3 is used to limit current, preventing damage to the optocoupler isolator due to excessive primary current. Fourth resistor R4, connected in parallel with the primary side of the optocoupler isolator, primarily provides a loop for freewheeling current when cooling fan 12 switches from running to stopping, that is, when the signal output from cooling fan control signal output terminal FAN switches from a low level to a high level. The secondary side of the optocoupler isolator reaches a conductive condition under the action of primary diode D2, and the PNP transistor Q also reaches a conductive condition. The power from the second voltage terminal VCC2 is provided to cooling fan 12 via the switch module 11 consisting of two transistors Q and a resettable fuse F1, thereby driving cooling fan 12.

[0075] As can be seen from the above description, the cooling fan drive circuit provided by the present invention utilizes a driver module 10, transistor Q, and a resettable fuse F1 to achieve reliable drive control and protection of the cooling fan 12 by the DSP main control chip. The circuit's switch module 11 utilizes a multi-way parallel connection, which can reduce the current level of the transistor Q and replace relatively high-current switching transistors such as more expensive MOS transistors. Furthermore, when the cooling fan 12 stalls or is clogged by dust, causing overcurrent in the cooling fan 12, the resettable fuse F1 is used in the driver circuit to effectively prevent damage to the driver circuit components. Furthermore, a Schottky diode D1 is connected in parallel across the cooling fan 12 drive power supply to effectively prevent damage to the cooling fan 12 and the driver circuit from the electromotive force generated when the cooling fan 12 stalls, providing a path for dissipating the electromotive force generated when the cooling fan 12 stalls. This cooling fan drive circuit is simpler and more reliable than other solutions.

[0076] Based on the driving circuit of the cooling fan provided in the above embodiments of the present invention, an inverter is also provided in another embodiment of the present invention, wherein the inverter includes a cooling fan and the driving circuit of the cooling fan described in any of the above embodiments, and the inverter has the same technical effect as the driving circuit of the cooling fan.

[0077] The above is a detailed introduction to the drive circuit and inverter of a cooling fan provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

[0078] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0079] It should also be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that the process, method, article, or apparatus comprising a series of elements inherent to the elements, or also including elements inherent to these processes, methods, articles, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0080] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A driving circuit for a cooling fan, characterized in that: The driving circuit of the cooling fan includes: a driving module and a switch module; The first end of the driving module is electrically connected to the cooling fan control signal output end, the second end is electrically connected to the first voltage end, the third end is electrically connected to the first end of the switch module, and the fourth end is grounded; The second end of the switch module is electrically connected to the second voltage end, the third end of the switch module is electrically connected to the first end of the cooling fan, and the second end of the cooling fan is grounded; The switch module includes at least two switch units connected in parallel, and the switch unit includes at least a transistor, the emitter of the transistor is electrically connected to the second voltage end, the collector of the transistor is electrically connected to the first end of the cooling fan, and the base of the transistor is electrically connected to the second voltage end and the third end of the driving module respectively; The driving module is used to control the working state of the switch module according to the control signal output by the cooling fan control signal output terminal.

2. The driving circuit of the heat dissipation fan according to claim 1, characterized in that: The switch unit further includes: a first resistor; The base of the transistor is electrically connected to the second voltage terminal through the first resistor.

3. The driving circuit of the heat dissipation fan according to claim 1, characterized in that: The switch unit further includes: a current limiting protection subunit; The base of the transistor is electrically connected to the third terminal of the driving module through the current limiting protection subunit.

4. The driving circuit of the heat dissipation fan according to claim 3, characterized in that: The current limiting protection subunit is a second resistor; One end of the second resistor is electrically connected to the base of the transistor, and the other end of the second resistor is electrically connected to the third end of the driving module.

5. The driving circuit of the heat dissipation fan according to claim 1, characterized in that: The switch unit further includes: an overcurrent protection subunit; The collector of the transistor is electrically connected to the first end of the cooling fan through the overcurrent protection subunit; The overcurrent protection subunit is configured to be in an off state when the current flowing through it is greater than or equal to a preset current, and to be in an on state when the current flowing through it is less than the preset current.

6. The driving circuit of the heat dissipation fan according to claim 5, characterized in that: The overcurrent protection subunit is a self-recovery fuse; One end of the self-recovery fuse is electrically connected to the collector of the transistor, and the other end is electrically connected to the first end of the cooling fan.

7. The driving circuit of the heat dissipation fan according to claim 1, characterized in that: The driving circuit of the heat dissipation fan further includes: a Schottky diode; The cathode of the Schottky diode is electrically connected to the first end of the heat dissipation fan, and the anode of the Schottky diode is electrically connected to the second end of the heat dissipation fan.

8. The driving circuit of the heat dissipation fan according to claim 1, wherein: The driving module includes an isolation device.

9. The driving circuit of the heat dissipation fan according to claim 8, characterized in that: The driving module further includes: a third resistor and a fourth resistor; The first end of the third resistor is electrically connected to the cooling fan control signal output end, and the second end of the third resistor and the first end of the fourth resistor are both electrically connected to the first end of the isolation device; The second end of the fourth resistor is electrically connected to the first voltage end and the second end of the isolation device respectively.

10. A frequency converter, characterized in that: The frequency converter includes a cooling fan and a driving circuit for the cooling fan according to any one of claims 1 to 9.

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