Fan fault feedback circuit and fan

Abstract

The invention provides a fan fault feedback circuit and a fan, and relates to the technical field of fan fault detection, the fan fault feedback circuit comprises a band-pass circuit, a voltage division circuit, a comparator, an optical coupler and a control chip; when a first fan feedback signal is received, a first band-pass circuit in the band-pass circuits is conducted; when a feedback signal of the second fan is received, a second band-pass circuit in the band-pass circuits is conducted; the comparator controls the conduction of the optical coupler according to the first fan feedback signal or the second fan feedback signal; the control chip determines the running state of the current fan according to the conduction state of the optocoupler so as to relieve the technical problem that the fan fault detection accuracy is not high due to the fact that the same fan fault feedback circuit cannot adapt to different types of fan feedback signals.

Description

Technical Field

[0001] The present invention relates to the technical field of fan fault detection, and in particular to a fan fault feedback circuit and a fan. Background Art

[0002] In modern electronic devices, circuit design, logic circuit technology and isolation technology are crucial components. Circuit design technology mainly involves the construction and optimization of circuits, including power circuits, signal processing circuits, control circuits, etc. Fault feedback technology uses electronic components and circuits to detect whether the device signal is normal to achieve normal operation of the equipment. Isolation technology achieves electrical isolation in the circuit to prevent current leakage and improve system reliability and safety.

[0003] The existing fan feedback circuit uses an inverter to perform signal shaping and obtain the required level signal, and then sends the level signal to the control chip for detection to realize fan fault detection.

[0004] The inventors have found that there are some problems with the existing fan feedback circuit. First, there are differences in the feedback signals of various fan manufacturers, which generally include two signals: the (Rotation Detector, RD) signal and the (Frequency Generator, FG) signal for detecting the rotation status of the fan; the FG signal is a square wave frequency signal fed back by the fan according to its motor speed; the RD signal and the FG signal require different detection logic to determine whether the fan is operating normally, making this type of feedback circuit unable to be applied in the production process of different fans, that is, the application of the feedback circuit has limitations. Summary of the invention

[0005] The object of the present invention is to provide a fan fault feedback circuit and a fan, so as to alleviate the technical problem in the prior art that the same fan fault feedback circuit cannot adapt to different types of fan feedback signals, thereby resulting in low fan fault detection accuracy.

[0006] In a first aspect, an embodiment of the present invention provides a fan fault feedback circuit, comprising: a bandpass circuit, a voltage divider circuit, a comparator, an optocoupler, and a control chip; the bandpass circuit and the voltage divider circuit are respectively connected to the power supply end of the current fan;

[0007] The bandpass circuit is connected to the positive input terminal of the comparator, the voltage divider circuit is connected to the negative input terminal of the comparator, the output terminal of the comparator is connected to the optocoupler, and the optocoupler is connected to the control chip;

[0008] When a first fan feedback signal is received, a first band-pass circuit in the band-pass circuits is turned on; when a second fan feedback signal is received, a second band-pass circuit in the band-pass circuits is turned on;

[0009] The comparator controls the conduction of the optocoupler according to the first fan feedback signal or the second fan feedback signal;

[0010] The control chip determines the current operating state of the fan according to the conduction state of the optocoupler.

[0011] In combination with the first aspect, an embodiment of the present invention provides a first possible implementation of the first aspect, wherein the bandpass circuit includes a switching switch, a first target component, a second target component and a common circuit portion;

[0012] One end of the switch inputs a fan feedback signal, the other end of the switch is respectively connected to one end of the first target component and one end of the second target component, and the other end of the first target component and the other end of the second target component are respectively connected to the common circuit part;

[0013] The switching switch, under the action of the fan feedback signal, selects the first target component and the common circuit part as the first band-pass circuit for conduction, or selects the second target component and the common circuit part as the second band-pass circuit for conduction.

[0014] In combination with the first aspect, the embodiment of the present invention provides a second possible implementation of the first aspect, wherein the common circuit portion includes an impedance R1, an impedance R2, a capacitor C1 and a diode D1;

[0015] One end of the impedance R1 is respectively connected to one end of the first target component, one end of the second target component, one end of the impedance R2 and one end of the diode D1;

[0016] The other end of the impedance R1 is grounded, and the other end of the diode D1 is grounded;

[0017] The other end of the impedance R2 is respectively connected to one end of the capacitor C1, the positive input end of the comparator and one end of the feedback resistor R3 of the comparator;

[0018] The other end of the capacitor C1 is grounded.

[0019] In combination with the first aspect, an embodiment of the present invention provides a third possible implementation of the first aspect, wherein, when the first fan feedback signal is a square wave frequency FG signal of the current fan, the first target component is a capacitor C2;

[0020] In the case where the second fan feedback signal is the rotation state RD signal of the current fan, the second target component is the resistor R4; wherein the rotation state RD signal is a signal that maintains a high level or a low level for a preset time period.

[0021] In combination with the first aspect, an embodiment of the present invention provides a fourth possible implementation of the first aspect, wherein, when the first fan feedback signal is within a preset frequency range, the input voltage of the positive input terminal of the comparator is greater than the input voltage of the negative input terminal, the output of the comparator is in a suspended state, and the optocoupler is controlled to be turned on; when the first fan feedback signal is not within the preset frequency range, the input voltage of the positive input terminal of the comparator is less than the input voltage of the negative input terminal, the output of the comparator is a low level, and the optocoupler is controlled to be turned off;

[0022] When the second fan feedback signal is at a high level, the input voltage at the positive input terminal of the comparator is greater than the input voltage at the negative input terminal, and the output of the comparator is in a floating state, controlling the optocoupler to be turned on; when the second fan feedback signal is at a low level, the input voltage at the positive input terminal of the comparator is less than the input voltage at the negative input terminal, and the output of the comparator is at a low level, controlling the optocoupler to be turned off.

[0023] In combination with the first aspect, an embodiment of the present invention provides a fifth possible implementation of the first aspect, wherein when the optocoupler is turned on, the control chip determines that the current fan is in a normal operating state;

[0024] When the optocoupler is turned off, the control chip determines that the current fan is in a faulty operating state or a stopped operating state.

[0025] In combination with the first aspect, an embodiment of the present invention provides a sixth possible implementation manner of the first aspect, wherein the first target component includes a plurality of components, the second target component includes a plurality of components, and each of the first target component or the second target component has different parameters;

[0026] The switching switch selects the corresponding first target component and the second target component to be turned on according to the current fan speed range.

[0027] In combination with the first aspect, an embodiment of the present invention provides a seventh possible implementation of the first aspect, wherein, when the first fan feedback signal or the second fan feedback signal is at a negative level, the diode D1 is used to pull the negative level up to a low level.

[0028] In combination with the first aspect, an embodiment of the present invention provides an eighth possible implementation manner of the first aspect, wherein the eighth possible implementation manner further includes a chip power supply terminal connected to the control chip;

[0029] The optocoupler is also used to isolate the power supply end of the fan from the power supply end of the chip.

[0030] In a second aspect, an embodiment of the present invention further provides a fan, comprising the fan fault feedback circuit as described above, and also comprising a fan body and a control unit;

[0031] The control unit is connected to the fan fault feedback circuit, and controls the fan body according to the current running state of the fan sent by the fan fault feedback circuit.

[0032] The embodiment of the present invention provides a fan fault feedback circuit and a fan, in which different types of fan feedback signals can turn on the corresponding circuit parts in the bandpass circuit, thereby achieving the purpose of adapting to different types of fan feedback signals; on this basis, the turned-on first bandpass circuit or the second bandpass circuit inputs the fan feedback signal to the positive electrode of the comparator, and the comparator controls the conduction state of the optocoupler based on its positive and negative inputs, so that the control chip can know whether there is a fault in the current operating state of the fan based on the conduction state of the optocoupler, thereby ensuring the wide adaptability of the fan feedback circuit.

[0033] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description and the drawings.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A block diagram of a fan fault feedback circuit provided by an embodiment of the present invention;

[0037] Figure 2 Another fan fault feedback circuit block diagram provided by an embodiment of the present invention;

[0038] Figure 3 A schematic diagram of a fan fault feedback circuit structure provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0040] At present, the RD signal and FG signal are sent to the control chip through the shaping circuit, and different programs need to be applied for detection. For example, different hardware and software are needed for fault detection, which limits the material replacement of the fan. Moreover, in actual applications, the control chip directly detects the RD signal and FG signal of the fan, which will have certain safety hazards. The pulse current of the fan will affect the normal operation of the control chip and even cause chip breakdown.

[0041] Based on this, a fan fault feedback circuit and a fan provided in an embodiment of the present invention can adapt to different fan feedback signals to turn on the corresponding bandpass circuit parts, thereby ensuring that the fan fault feedback circuit can be adapted to different models of fans, improving the wide range of applications, and avoiding fan pulse breakdown of the control chip through optocoupler isolation, thereby improving the application reliability of the fan fault feedback circuit.

[0042] The following is a detailed description through examples.

[0043] Figure 1 A block diagram of a fan fault feedback circuit provided by an embodiment of the present invention.

[0044] Reference Figure 1 The fan fault feedback circuit includes: a bandpass circuit, a voltage divider circuit, a comparator, an optocoupler and a control chip; the bandpass circuit and the voltage divider circuit are respectively connected to the power supply end of the current fan, and the control chip is connected to the chip power supply end;

[0045] The bandpass circuit is connected to the positive input terminal of the comparator, the voltage divider circuit is connected to the negative input terminal of the comparator, the output terminal of the comparator is connected to the optocoupler, and the optocoupler is connected to the control chip;

[0046] When a first fan feedback signal is received, a first band-pass circuit in the band-pass circuit is turned on; when a second fan feedback signal is received, a second band-pass circuit in the band-pass circuit is turned on;

[0047] The comparator controls the conduction of the optocoupler according to the first fan feedback signal or the second fan feedback signal;

[0048] The control chip determines the current operating state of the fan according to the conduction state of the optocoupler.

[0049] Wherein, under the action of the turned-on first bandpass circuit or the turned-on second bandpass circuit, the comparator compares the first fan feedback signal or the second fan feedback signal inputted at its positive input terminal with the inputted at its negative input terminal, thereby controlling the conduction or shut-down of the optocoupler;

[0050] It should be noted that the input of the negative input terminal of the comparator is a voltage value obtained by dividing the input voltage of the power supply terminal of the fan by the voltage divider circuit.

[0051] In a preferred embodiment of actual application, different categories of fan feedback signals can turn on the corresponding circuit parts in the bandpass circuit to achieve the purpose of adapting to different categories of fan feedback signals; on this basis, the turned-on first bandpass circuit or the second bandpass circuit inputs the fan feedback signal to the positive electrode of the comparator, and the comparator controls the conduction state of the optocoupler based on its positive and negative inputs, so that the control chip can know whether there is a fault in the current operating state of the fan based on the conduction state of the optocoupler, thereby ensuring the wide adaptability of the fan feedback circuit.

[0052] As an optional embodiment, different components can be configured in the fan fault feedback circuit according to different categories of fan feedback signals to form a first bandpass circuit or a second bandpass circuit, so that under the action of different categories of fan feedback signals, the fan fault feedback circuit can adapt to detect the current operating status of the fan.

[0053] As another optional embodiment, the corresponding target component can be selected to conduct the corresponding passband circuit under the action of different feedback signals by switching the switch, thereby realizing the adaptive application of different fan feedback signals; Figure 2 As shown, the bandpass circuit includes a switching switch, a first target component, a second target component and a common circuit portion;

[0054] One end of the switch inputs a fan feedback signal, the other end of the switch is respectively connected to one end of the first target component and one end of the second target component, and the other end of the first target component and the other end of the second target component are respectively connected to a common circuit part;

[0055] The switching switch selects the first target component and the common circuit part as the first band-pass circuit for conduction, or selects the second target component and the common circuit part as the second band-pass circuit for conduction under the action of the fan feedback signal.

[0056] In some embodiments, based on different speed ranges of the current fan, a target component with a corresponding resistance value or capacitance value may be selected in the fan fault feedback circuit for configuration.

[0057] As a preferred embodiment, according to the actual application business scenario of the fan fault feedback circuit, a redundant number of target components can be pre-configured in the fan fault feedback circuit; the first target components include multiple, the second target components include multiple, and each first target component or second target component has different parameters;

[0058] The switch is switched to select the corresponding first target component and the second target component for conduction according to the current speed range of the fan.

[0059] Here, in the fan fault feedback circuit application, the switch can be controlled according to the current fan speed range to select a target component that meets the target capacitance or resistance requirements.

[0060] The control unit is connected to the fan fault feedback circuit, and is configured with a mapping rule between the fan speed and the target component parameters, so as to know which parameter target component the switch is controlled to select under which fan speed range.

[0061] In actual applications, the fan feedback signal may be abnormal. When the first fan feedback signal or the second fan feedback signal is at a negative level, the diode D1 is used to pull the negative level up to a low level; to prevent the input voltage at the positive input terminal of the comparator from being abnormal when the fan feedback signal is at a negative level.

[0062] In addition, the embodiment of the present invention also includes a chip power supply terminal connected to the control chip; the optical coupler is also used to isolate the fan power supply terminal and the chip power supply terminal. After the optical coupler is isolated, the power supply on both sides will not interfere with each other, and the power supply on both sides will not be damaged due to high voltage static electricity on the other side.

[0063] The fan feedback signal and the control chip signal are isolated by optocouplers to effectively deal with the impact of the fan pulsating current on the control chip power supply. The fan is an external device and has the problem of static electricity. After power isolation, the control chip is effectively protected from the influence of static electricity, thereby improving circuit reliability and safety.

[0064] Based on the above embodiment, when the first fan feedback signal is the square wave frequency FG signal of the current fan, the first target component is the capacitor C2. When the second fan feedback signal is the rotation state RD signal of the current fan, the second target component is the resistor R4.

[0065] The rotation state RD signal is a signal that maintains a high level or a low level for a preset time period.

[0066] In some embodiments, Figure 3It can be a schematic diagram of a fan fault feedback circuit structure that is in a conducting state when a first fan feedback signal is input, and the common circuit part includes an impedance R1, an impedance R2, a capacitor C1 and a diode D1;

[0067] One end of the impedance R1 is respectively connected to one end of the first target component, one end of the second target component, one end of the impedance R2 and one end of the diode D1; the other end of the impedance R1 is grounded, and the other end of the diode D1 is grounded; the other end of the impedance R2 is respectively connected to one end of the capacitor C1, the positive input end of the comparator and one end of the feedback resistor R3 of the comparator; the other end of the capacitor C1 is grounded.

[0068] Here, the resistor and capacitor are conventional SMD 0805 packages, the diode model can be 1N4148, the comparator model can be LM2903DR, and the optocoupler model can be EL3H7. Resistor R1, resistor R2, capacitor C1, capacitor C2, and diode D1 form a bandpass network circuit. Among them, the end of the target component away from the common circuit part is also connected to one end of resistor R4, and the other end of resistor R4 is connected to the power supply end of the fan; the fan feedback signal FBW1 is also connected to one end of resistor R4; Figure 3 As shown, when the fan feedback signal FBW1 is the first fan feedback signal, the target component in the on state of the connected circuit is the capacitor C2; as an optional embodiment, the fan power supply terminal can be 12V;

[0069] refer to Figure 3 As shown, the other end of the feedback resistor R3 is connected to the output end of the comparator; the negative input end of the comparator is connected to a voltage divider circuit, which includes a capacitor C3, a resistor R5 and a resistor R6;

[0070] One end of the capacitor C3, one end of the resistor R5 and one end of the resistor R6 are respectively connected to the negative input end of the comparator, the other end of the capacitor C3 and the other end of the resistor R6 are grounded, and the other end of the resistor R5 is connected to the power supply end of the fan;

[0071] Here, if the power supply terminal of the fan inputs a voltage of 12V, the resistance value of the resistor R5 is 10K, and the resistance value of the resistor R6 is 3K, then the input voltage of the negative input terminal of the comparator after voltage division processing can be 2.77V.

[0072] In addition, the first enable terminal of the comparator is connected to the power supply terminal of the fan and one end of the capacitor C4 respectively, the other end of the capacitor C4 is grounded, and the second enable terminal of the comparator is grounded.

[0073] In some embodiments, when the first fan feedback signal is within a preset frequency range, the input voltage at the positive input terminal of the comparator is greater than the input voltage at the negative input terminal, the output of the comparator is in a floating state, and the optocoupler is controlled to be turned on; when the first fan feedback signal is not within the preset frequency range, the input voltage at the positive input terminal of the comparator is less than the input voltage at the negative input terminal, the output of the comparator is a low level, and the optocoupler is controlled to be turned off.

[0074] In some embodiments, when the second fan feedback signal is at a high level, the input voltage at the positive input terminal of the comparator is greater than the input voltage at the negative input terminal, the output of the comparator is in a floating state, and the optocoupler is controlled to be turned on; when the second fan feedback signal is at a low level, the input voltage at the positive input terminal of the comparator is less than the input voltage at the negative input terminal, the output of the comparator is at a low level, and the optocoupler is controlled to be turned off.

[0075] Among them, the preset frequency range can be 60~180HZ; Figure 3 As shown, the output end of the comparator is respectively connected to one end of the pull-up resistor R7, one end of the resistor R8 and one end of the capacitor C5, the other end of the pull-up resistor R7 is connected to the power supply end of the fan, the other end of the capacitor C5 is grounded, the other end of the resistor R8 is connected to the first input end of the optocoupler, the second input end of the optocoupler is grounded, and the first output end of the optocoupler outputs a signal FAN-FBW1 for the control unit to learn the current operating status of the fan; the first output end of the optocoupler is respectively connected to one end of the capacitor C6, one end of the resistor R9, and one end of the resistor R10, the second output end of the optocoupler is grounded, and is also respectively connected to the other end of the capacitor C6, the other end of the resistor R10, and the other end of the resistor R9 is connected to the chip power supply end; for example, the chip power supply end can input +5V.

[0076] Here, under the action of the pull-up resistor R7, when the output of the comparator is in a suspended state, it actually outputs a high level.

[0077] Based on the above-mentioned embodiment, when the optocoupler is turned on, the control chip determines that the current fan is in a normal operating state, and the output signal FAN-FBW1 is a low level; when the optocoupler is turned off, the control chip determines that the current fan is in a faulty operating state or a stopped operating state, and the output signal FAN-FBW1 is a high level.

[0078] In some embodiments, an embodiment of the present invention further provides a fan, comprising the fan fault feedback circuit as described in the above embodiment, and also comprising a fan body and a control unit;

[0079] The control unit is connected to the fan fault feedback circuit, and determines the current operating state of the fan according to the level state of the output signal FAN-FBW1 sent by the fan fault feedback circuit, and then controls the fan body to work normally or stop working.

[0080] It should be noted that the control unit is also used to identify the category of the fan feedback signal, that is, to identify it as the first fan feedback signal or the second fan feedback signal, and then control the switching switch to select and turn on the corresponding target component and the pass-through circuit part; as another embodiment, the control unit is also used to control the switching switch to select a target component with a suitable resistance or capacitance from multiple redundantly configured target components to turn on the access circuit according to the preset fan speed and parameter mapping relationship between the target component and the current fan speed range.

[0081] The embodiment of the present invention adopts a bandpass circuit and changes the values ​​of capacitors and resistors to achieve compatible use of feedback signals of different fans; at the same time, the fan power supply and the control chip power supply are isolated through optical coupling isolation, which effectively reduces the impact of power supply jitter caused by fan rotation on the control chip, which is beneficial to the stable operation of the inverter system. The embodiment of the present invention can adapt to different fan types. The level and waveform of the fan output feedback signal of each manufacturer will be different, which is a great challenge to the sampling logic of the control chip. The feedback circuit is used to determine the fan operation status through a unified signal to the control chip; that is, when the fan is operating normally, the control chip outputs a low level; when the fan stops running or fails to run, the control chip outputs a high level. The sampling and control logic of the control unit is simplified.

[0082] The fan provided in the embodiment of the present invention has the same technical features as the fan fault feedback circuit provided in the above embodiment, and can therefore solve the same technical problems and achieve the same technical effects.

[0083] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0084] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0085] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0086] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0087] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0088] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the aforementioned embodiments, those of ordinary skill in the art should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the aforementioned embodiments within the technical scope disclosed by the present invention, or can easily conceive of changes, or make equivalent replacements for some of the technical features therein. Such modifications, changes or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the protection scope of the present invention.

Claims

1. A fan fault feedback circuit, characterized in that: include: A bandpass circuit, a voltage divider circuit, a comparator, an optocoupler and a control chip; the bandpass circuit and the voltage divider circuit are respectively connected to the power supply end of the current fan; The bandpass circuit is connected to the positive input terminal of the comparator, the voltage divider circuit is connected to the negative input terminal of the comparator, the output terminal of the comparator is connected to the optocoupler, and the optocoupler is connected to the control chip; When a first fan feedback signal is received, a first band-pass circuit in the band-pass circuits is turned on; when a second fan feedback signal is received, a second band-pass circuit in the band-pass circuits is turned on; The comparator controls the conduction of the optocoupler according to the first fan feedback signal or the second fan feedback signal; The control chip determines the current operating state of the fan according to the conduction state of the optocoupler.

2. The fan fault feedback circuit according to claim 1, characterized in that: The bandpass circuit includes a switch, a first target component, a second target component and a common circuit portion; One end of the switch inputs a fan feedback signal, the other end of the switch is connected to one end of the first target component and one end of the second target component respectively, and the other end of the first target component and the other end of the second target component are connected to the common circuit part respectively; The switching switch, under the action of the fan feedback signal, selects the first target component and the common circuit part as the first passband circuit for conduction, or selects the second target component and the common circuit part as the second passband circuit for conduction.

3. The fan fault feedback circuit according to claim 2, characterized in that: The common circuit portion includes an impedance R1, an impedance R2, a capacitor C1 and a diode D1; One end of the impedance R1 is respectively connected to one end of the first target component, one end of the second target component, one end of the impedance R2 and one end of the diode D1; The other end of the impedance R1 is grounded, and the other end of the diode D1 is grounded; The other end of the impedance R2 is respectively connected to one end of the capacitor C1, the positive input end of the comparator and one end of the feedback resistor R3 of the comparator; The other end of the capacitor C1 is grounded.

4. The fan fault feedback circuit according to claim 2, characterized in that: In the case where the first fan feedback signal is the square wave frequency FG signal of the current fan, the first target component is the capacitor C2; In the case where the second fan feedback signal is the rotation state RD signal of the current fan, the second target component is the resistor R4; wherein the rotation state RD signal is a signal that maintains a high level or a low level for a preset time period.

5. The fan fault feedback circuit according to claim 4, characterized in that: When the first fan feedback signal is within the preset frequency range, the input voltage of the positive input terminal of the comparator is greater than the input voltage of the negative input terminal, the output of the comparator is in a floating state, and the optocoupler is controlled to be turned on; when the first fan feedback signal is not within the preset frequency range, the input voltage of the positive input terminal of the comparator is less than the input voltage of the negative input terminal, the output of the comparator is low level, and the optocoupler is controlled to be turned off; When the second fan feedback signal is at a high level, the input voltage at the positive input terminal of the comparator is greater than the input voltage at the negative input terminal, and the output of the comparator is in a floating state, controlling the optocoupler to be turned on; when the second fan feedback signal is at a low level, the input voltage at the positive input terminal of the comparator is less than the input voltage at the negative input terminal, and the output of the comparator is at a low level, controlling the optocoupler to be turned off.

6. The fan fault feedback circuit according to claim 5, characterized in that: When the optocoupler is turned on, the control chip determines that the current fan is in a normal operating state; When the optocoupler is turned off, the control chip determines that the current fan is in a faulty operating state or a stopped operating state.

7. The fan fault feedback circuit according to claim 2, characterized in that: The first target components include a plurality of components, the second target components include a plurality of components, and each of the first target components or the second target components has different parameters; The switching switch selects the corresponding first target component and the second target component to be turned on according to the current fan speed range.

8. The fan fault feedback circuit according to claim 3, characterized in that: When the first fan feedback signal or the second fan feedback signal is at a negative level, the diode D1 is used to pull the negative level up to a low level.

9. The fan fault feedback circuit according to claim 1, characterized in that: It also includes a chip power supply terminal connected to the control chip; The optocoupler is also used to isolate the power supply end of the fan from the power supply end of the chip.

10. A fan, characterized in that: The fan fault feedback circuit according to any one of claims 1 to 9 further comprises a fan body and a control unit; The control unit is connected to the fan fault feedback circuit, and controls the fan body according to the current running state of the fan sent by the fan fault feedback circuit.

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