Fan state detection circuit

Abstract

The embodiment of the invention discloses a fan state detection circuit, the circuit comprises a feedback switch power supply module, a fan detection module, an alarm module, a comparison module and a protection module, the feedback switch power supply module is electrically connected with the protection module, and the protection module is electrically connected with the comparison module. The comparison module is electrically connected with the fan detection module and the alarm module, and the fan detection module is electrically connected with a fan. According to the fan state detection circuit, the fan state is detected through the voltage signal generated when the fan runs, when the fan reaches the over-current threshold value, the fan is turned off in time, and compared with a fan rotating speed signal detection mode, the fan state detection circuit is high in response speed and anti-interference capacity, and reliability and real-time performance of fan state detection are improved.

Description

Technical Field

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

[0002] With the continuous development of electronic equipment, high-power fans are widely used in servers, industrial equipment, communication equipment and other fields due to their efficient heat dissipation performance. However, as a mechanical device, fans may fail due to various reasons during operation. If these failures cannot be detected and handled in time, the heat dissipation effect of the equipment will be seriously affected, and even cause overheating and damage to the equipment, resulting in huge economic losses.

[0003] Most existing fans use software monitoring to determine whether the fan is working properly by detecting the fan speed signal. However, this method has disadvantages such as slow response speed and susceptibility to interference, and the reliability and real-time performance of high-power fan status detection are low. Summary of the invention

[0004] To solve the problems existing in the prior art, one or more embodiments of this specification describe a fan status detection circuit.

[0005] A fan status detection circuit is provided in the present application, and the circuit includes a feedback switching power supply module, a fan detection module, an alarm module, a comparison module and a protection module. The feedback switching power supply module is electrically connected to the protection module, the protection module is electrically connected to the comparison module, the comparison module is electrically connected to the fan detection module and the alarm module, and the fan detection module is electrically connected to the fan.

[0006] Preferably, the fan detection module includes a current collection resistor and an operational amplifier, the first end of the current collection resistor is electrically connected to the first end of the fan, the second end is connected to the voltage input, the second end of the fan is grounded, the first input end of the operational amplifier is electrically connected to the first end of the current collection resistor, and the second input end of the operational amplifier is electrically connected to the second end of the current collection resistor.

[0007] Preferably, the comparison module includes a voltage follower and a comparator, a first input terminal of the comparator is electrically connected to an output terminal of the voltage follower, and a second input terminal of the comparator is electrically connected to an output terminal of the operational amplifier.

[0008] Preferably, the alarm module includes a first transistor, a first pull-up resistor and a buzzer, the first terminal of the first transistor is connected to a voltage input, the second end of the first transistor is electrically connected to the comparison module, the third end of the first transistor is electrically connected to the first end of the buzzer, the second end of the buzzer is grounded, the first end of the first pull-up resistor is electrically connected to the first end of the first transistor, and the second end of the first pull-up resistor is electrically connected to the second end of the first transistor.

[0009] Preferably, the alarm module further comprises an adjusting resistor, a first end of the adjusting resistor is electrically connected to a first end of the buzzer, and a second end of the adjusting resistor is electrically connected to a second end of the buzzer.

[0010] Preferably, the protection module includes a relay, a second transistor and a second pull-up resistor, the first end of the second transistor is connected to the voltage input, the second end of the second transistor is electrically connected to the comparison module, the third end of the second diode is electrically connected to the first end of the relay, the second end of the relay is electrically connected to the feedback switch power supply module, the first end of the second pull-up resistor is electrically connected to the first end of the second transistor, and the second end of the second pull-up resistor is electrically connected to the second end of the second transistor.

[0011] Preferably, the feedback switching power supply module includes a winding resistor, a rectifier unit, a PWM controller and a transformer, the first end of the winding resistor is electrically connected to the protection module, the second end of the winding resistor is electrically connected to the rectifier unit, the rectifier unit is electrically connected to the PWM controller, and the PWM controller is electrically connected to the transformer.

[0012] Preferably, the feedback switching power supply module also includes a first high-voltage electrolytic capacitor, a second high-voltage electrolytic capacitor, a first equalizing resistor and a second equalizing resistor, the first end of the first high-voltage electrolytic capacitor is electrically connected to the first interface of the transformer, the second end of the first high-voltage electrolytic capacitor is electrically connected to the first end of the second high-voltage electrolytic capacitor, the second end of the second high-voltage electrical capacitor is grounded, the first end of the first equalizing resistor is electrically connected to the first end of the first high-voltage electrolytic capacitor, the second end of the first equalizing resistor is electrically connected to the second end of the first high-voltage electrolytic capacitor, the first end of the second equalizing resistor is electrically connected to the second end of the first high-voltage electrolytic capacitor, and the second end of the second equalizing resistor is grounded.

[0013] Preferably, the feedback switching power supply module also includes a peak absorption resistor, a peak absorption capacitor and a peak absorption diode, the first end of the peak absorption diode is electrically connected to the SW pin of the PWM controller, the second end of the peak absorption diode is electrically connected to the first end of the peak absorption resistor, the second end of the peak absorption resistor is electrically connected to the first interface of the transformer, the first end of the peak absorption capacitor is electrically connected to the first end of the peak absorption resistor, and the second end of the peak absorption capacitor is electrically connected to the second end of the peak absorption resistor.

[0014] Preferably, the feedback switch power supply module further comprises a dummy load resistor, a first end of the dummy load resistor is connected to a voltage input, and a second end of the dummy load resistor is grounded.

[0015] The beneficial effects of the present invention are: 1. The fan status detection circuit provided in the embodiments of this specification detects the fan status through the voltage signal when the fan is running, and disconnects the fan in time when the fan reaches the overcurrent threshold. Compared with the method of detecting the fan speed signal, the fan status detection circuit has a fast response speed and strong anti-interference ability, thereby improving the reliability and real-time performance of the fan status detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a schematic diagram of the architecture of a fan status detection circuit in the specific implementation of this specification; Figure 2 It is a schematic diagram of a fan status detection circuit in the specific implementation of this specification; Figure 3 It is a detection flow diagram of a fan status detection circuit in the specific implementation of this specification. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0019] In the following introduction, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The following introduction provides multiple embodiments of the present application, and different embodiments can be replaced or combined, so the present application can also be considered to include all possible combinations of the same and / or different embodiments recorded. Therefore, if one embodiment includes features A, B, and C, and another embodiment includes features B and D, then the present application should also be considered to include embodiments containing one or more of all other possible combinations of A, B, C, and D, although the embodiment may not be clearly recorded in the following text.

[0020] The following description provides examples and does not limit the scope, applicability or examples set forth in the claims. Changes may be made to the functions and arrangements of the elements described without departing from the scope of the present application. Various processes or components may be appropriately omitted, substituted or added to each example. For example, the described method may be performed in an order different from the order described, and various steps may be added, omitted or combined. In addition, features described in some examples may be combined in other examples.

[0021] See also Figure 1 and Figure 2 , Figure 1 A schematic diagram of the architecture of a fan status detection circuit provided in an embodiment of this specification is shown: like Figure 1 , Figure 2 As shown, the fan status detection circuit includes a feedback switch power module, a fan detection module, an alarm module, a comparison module and a protection module. The feedback switch power module is electrically connected to the protection module, the protection module is electrically connected to the comparison module, the comparison module is electrically connected to the fan detection module and the alarm module, and the fan detection module is electrically connected to the fan (in Figure 2The feedback switch power supply module, fan detection module, alarm module, comparison module and protection module can be field programmable gate array (FPGA), integrated circuit (IC), etc. The fan detection module obtains the voltage signal when the fan is running, and then sends the obtained voltage signal to the comparison module. The comparison module generates a detection result according to the voltage signal. The detection result is that the fan reaches the threshold or the fan does not reach the threshold. When the comparison module outputs the detection result indicating that the fan reaches the threshold, the alarm module outputs an alarm signal, and the protection module disconnects the connection between the feedback switch power supply module and the fan detection module, and the fan stops rotating; when the comparison module outputs the detection result indicating that the fan does not reach the threshold, the alarm module does not operate, and the feedback switch power supply module continues to provide the power required for the operation of the entire system. The present application detects the fan status through the voltage signal when the fan is running, and disconnects the fan in time when the fan reaches the overcurrent threshold. Compared with the method of detecting the fan speed signal, the fan status detection circuit has a fast response speed and strong anti-interference ability, which improves the reliability and real-time performance of the fan status detection.

[0022] In one embodiment, the fan detection module includes a current collection resistor 101, an operational amplifier 102, a first bias resistor 103, a second bias resistor 104, a third bias resistor 105, a fourth bias resistor 106 and a self-oscillation suppression capacitor 107, the first end of the current collection resistor 101 is electrically connected to the first end of the fan, the second end is connected to the voltage input, the second end of the fan is grounded, the first end of the first bias resistor 103 is electrically connected to the first input end of the operational amplifier 102, the second end of the first bias resistor 103 is electrically connected to the first end of the current collection resistor 101, the first end of the second bias resistor 104 is electrically connected to the second input end of the operational amplifier 102, and the second end of the second bias resistor 104 is electrically connected to the current collection resistor 101. The second end is electrically connected, the first end of the third bias resistor 105 is electrically connected to the first end of the second bias resistor 104, the second end of the third bias resistor 105 is grounded, the first end of the fourth bias resistor 106 is electrically connected to the first end of the first bias resistor 103, the second end of the fourth bias resistor 106 is electrically connected to the output end of the operational amplifier 102, the first end of the self-oscillation suppression capacitor 107 is electrically connected to the first end of the first bias resistor 103, the second end of the self-oscillation suppression capacitor 107 is electrically connected to the first end of the second bias resistor 104, the current acquisition resistor 101 converts the current signal of the fan into a voltage signal, the operational amplifier 102 collects the voltage across the current acquisition resistor 101, and outputs the voltage signal through the output end of the operational amplifier 102. The high-frequency oscillation existing in the fan detection module is suppressed by setting the self-oscillation suppression capacitor 107 to improve the stability of the circuit.

[0023] In one embodiment, the comparison module includes a voltage follower 108, a comparator 109, a first voltage-dividing resistor 110, a second voltage-dividing resistor 111, a first filter capacitor 112, a second filter capacitor 113, a third filter capacitor 114 and a transition resistor 115, wherein a first end of the transition resistor 115 is electrically connected to the output end of the operational amplifier 102, a second end of the transition resistor 115 is electrically connected to a second input end of the comparator 109, a first input end of the comparator 109 is electrically connected to the output end of the voltage follower 108, a first input end of the voltage follower 108 is electrically connected to a first end of the first voltage-dividing resistor 110, a second input end of the voltage follower 108 is electrically connected to the output end of the voltage follower 108, a second end of the first voltage-dividing resistor 110 is electrically connected to a voltage input, and a second end of the second voltage-dividing resistor 111 is electrically connected to a voltage input. One end is electrically connected to the first end of the first voltage-dividing resistor 110, the second end of the second voltage-dividing resistor 111 is grounded, the first end of the first filter capacitor 112 is electrically connected to the first end of the second voltage-dividing resistor 111, the second end of the first filter capacitor 112 is electrically connected to the second end of the second voltage-dividing resistor 111, the first end of the second filter capacitor 113 is electrically connected to the second input terminal of the comparator 109, the second end of the second filter capacitor 113 is grounded, the first end of the third filter capacitor 114 is electrically connected to the first input terminal of the comparator 109, the second end of the third filter capacitor 114 is grounded, the voltage follower 108 outputs a voltage threshold and compares it with the voltage signal output by the operational amplifier 102 on the comparator 109, when the inverting terminal voltage is higher than the inverting terminal voltage, the comparator 109 outputs a high level, otherwise it outputs a low level.

[0024] In one embodiment, the alarm module includes a first transistor 116, a first pull-up resistor 117, a buzzer 118, a fourth filter capacitor 119 and a first base resistor 120, the first terminal of the first transistor 116 is connected to a voltage input, the second end of the first transistor 116 is electrically connected to the first end of the first base resistor 120, the second end of the first base resistor 120 is electrically connected to the comparison module (the output end of the comparator 109 in this application), the third end of the first transistor 116 is electrically connected to the first end of the buzzer 118, the second end of the buzzer 118 is grounded, and the fourth filter capacitor 119 is electrically connected to the comparison module 116. The first end of is electrically connected to the first end of the first transistor 116, the second end of the fourth filter capacitor 119 is grounded, the first end of the first pull-up resistor 117 is electrically connected to the first end of the first transistor 116, and the second end of the first pull-up resistor 117 is electrically connected to the second end of the first transistor 116. By setting the first pull-up resistor 117, it is ensured that the first transistor 116 is always at a high level when turned off, thereby avoiding false alarms of the buzzer 118 and improving the stability of the circuit. When the fan reaches the overcurrent threshold, the comparator 109 outputs a low level, at which time the first transistor 116 is turned on and the buzzer 118 is started.

[0025] Furthermore, the alarm module also includes an adjusting resistor 121, a first end of the adjusting resistor 121 is electrically connected to a first end of the buzzer 118, and a second end of the adjusting resistor 121 is electrically connected to a second end of the buzzer 118. By setting the adjusting resistor 121, the current passing through the buzzer 118 is adjusted, thereby adjusting the sound volume of the buzzer 118.

[0026] In one embodiment, the protection module includes a relay 122, a second triode 123, a second pull-up resistor 124, a second base resistor 125 and a collector resistor 126, a first terminal of the second triode 123 is connected to a voltage input, a second end of the second triode 123 is electrically connected to a first end of the second base resistor 125, a second end of the second base resistor 125 is electrically connected to a comparison module (an output end of the comparator 109 in the present application), a third end of the second triode 123 is electrically connected to a first end of the relay 122 and a first end of the collector resistor 126, and a collector The second end of the resistor 126 is grounded, the first end of the second pull-up resistor 124 is electrically connected to the first end of the second transistor 123, and the second end of the second pull-up resistor 124 is electrically connected to the second end of the second transistor 123. When the fan reaches the overcurrent threshold, the comparator 109 outputs a low level, the second transistor 123 is turned on, and the relay 122 works to disconnect the power supply, thereby protecting the fan. By setting the second pull-up resistor 124, it is ensured that the second transistor 123 is always at a high level when turned off, thereby avoiding the relay 122 from disconnecting the power supply when the fan is working normally, thereby improving the stability of the circuit.

[0027] In one embodiment, the feedback switch module includes a winding resistor 127, a varistor 128, an I-shaped inductor 129, a first capacitor 130, a first rectifier diode 131, a second rectifier diode 132, a third rectifier diode 133, a fourth rectifier diode 134, a transformer 135, a PWM controller 136, a first resistor 137, a second resistor 138, a second capacitor 139, a third capacitor 140, a first current limiting resistor 141, a second current limiting resistor 142, a third current limiting resistor 143, an energy storage electrolytic capacitor 144, a fifth rectifier diode 145, a feedback optocoupler 146, a third voltage divider resistor 147, a fourth voltage divider resistor 148, a fifth voltage divider resistor 149, and a fifth filter capacitor 150. , a sixth filter capacitor 151, a seventh filter capacitor 152, a fourth current limiting resistor 153, a fourth capacitor 154, a fifth capacitor 155, a reference voltage source 156, a third resistor 157, an eighth filter capacitor 158, a ninth filter capacitor 159, a filter inductor 160, a first diode 161, a second diode 162, a sixth capacitor 163 and a fourth resistor 164, a first end of the winding resistor 127 is electrically connected to the second end of the relay 122 and the first end of the varistor 128, a second end of the winding resistor 127 is electrically connected to the first end of the I-shaped inductor 129, the winding resistor 127 is used to suppress the surge current generated at the moment of power-on, a second end of the I-shaped inductor 129 is electrically connected to the first end of the first capacitor 130, the first The first end of the rectifier diode 131 and the second end of the second rectifier diode 132 are electrically connected, the I-shaped inductor 129 is used for filtering, thereby improving EMI (electromagnetic interference), the second end of the first capacitor 130 is electrically connected to the second end of the varistor 128, the input voltage test point 173, the first end of the third rectifier diode 133 and the second end of the fourth rectifier diode 134, when the AC voltage exceeds the threshold of the varistor 128, the varistor 128 is turned on to protect the subsequent circuit, the first end of the second rectifier diode 132 and the first end of the fourth rectifier diode 134 are grounded, the second end of the first rectifier diode 131 and the second end of the third rectifier diode 133 are electrically connected to the first interface of the transformer 135 The first rectifier diode 131, the second rectifier diode 132, the third rectifier diode 133 and the fourth rectifier diode 134 form a rectifier unit for rectifying AC power into DC power. The second interface of the transformer 135 is electrically connected to the SW pin of the PWM controller 136. The CS pin of the PWM controller 136 is electrically connected to the first end of the first resistor 137 and the first end of the second resistor 138. The second end of the first resistor 137 and the second end of the second resistor 138 are grounded. The GND pin of the PWM controller 136 is grounded. The VDD pin of the PWM controller 136 is electrically connected to the first end of the second capacitor 139 and the first end of the first current limiting resistor 141. The second end of the second capacitor 139 is grounded.The second end of the first current limiting resistor 141 is electrically connected to the first end of the third current limiting resistor 143 and the first end of the energy storage electrolytic capacitor 144, the second end of the energy storage electrolytic capacitor 144 is grounded, the second end of the third current limiting resistor 143 is electrically connected to the first end of the fifth rectifier diode 145, the second end of the fifth rectifier diode 145 is electrically connected to the third interface of the transformer 135, the fourth interface of the transformer 135 is grounded, the COM pin of the PWM controller 136 is electrically connected to the first end of the third capacitor 140 and the first end of the second current limiting resistor 142, the second end of the third capacitor 140 is grounded, and the second end of the second current limiting resistor 142 is electrically connected to the reverse The first end of the feedback optical coupler 146 is electrically connected, the second end of the feedback optical coupler 146 is grounded, the third end of the feedback optical coupler 146 is electrically connected to the first end of the third voltage-dividing resistor 147 and the first end of the fourth current-limiting resistor 153, the second end of the third voltage-dividing resistor 147 is electrically connected to the first end of the fourth voltage-dividing resistor 148 and the first end of the fourth capacitor 154, the second end of the fourth capacitor 154 is grounded, the second end of the fourth voltage-dividing resistor 148 is electrically connected to the first end of the fifth capacitor 155, the first end of the fifth filter capacitor 150, the first end of the reference voltage source 156, the first end of the sixth filter capacitor 151, and the first end of the fifth voltage-dividing resistor 149 The second end of the fifth capacitor 155 is electrically connected to the first end of the third resistor 157, the second end of the third resistor 157 is electrically connected to the second end of the fourth current limiting resistor 153, the second end of the fifth filter capacitor 150, the second end of the reference voltage source 156, the first end of the seventh filter capacitor 152 and the fourth end of the feedback optical coupler 146, the second end of the seventh filter capacitor 152, the third end of the reference voltage source 156, the second end of the sixth filter capacitor 151 and the second end of the fifth voltage-dividing resistor 149 are grounded, the third end of the feedback optical coupler 146 is electrically connected to the first end of the eighth filter capacitor 158, the first end of the filter inductor 160, the first and second ends of the eighth filter capacitor 158 and the eighth filter inductor 160, the first and second ends of the eighth filter capacitor 158 and the eighth filter inductor 160, the first and second ends of the eighth filter capacitor 158 and the eighth filter inductor 160, the first and second ends of the eighth filter capacitor 158 and the eighth filter inductor 160, the first and second ends of the eighth filter capacitor 158 and the eighth filter inductor 160, the first and second ends of the eighth filter capacitor 152 ... The first end of the pole tube 161 is electrically connected to the first end of the sixth capacitor 163, the second end of the filter inductor 160 is electrically connected to the first end of the second diode 162, the second end of the second diode 162 is electrically connected to the first end of the ninth filter capacitor 159, the second end of the sixth capacitor 163 is electrically connected to the first end of the fourth resistor 164, the second end of the fourth resistor 164 and the second end of the first diode 161 are electrically connected to the fifth interface of the transformer 135, the sixth interface of the transformer 135, the second end of the eighth filter capacitor 158 and the second end of the ninth filter capacitor 159 are grounded, and the second end of the second diode 162 is connected to the voltage input.

[0028] Furthermore, the feedback switch power supply module also includes a first high-voltage electrolytic capacitor 165, a second high-voltage electrolytic capacitor 166, a first equalizing resistor 167 and a second equalizing resistor 168. The first end of the first high-voltage electrolytic capacitor 165 is electrically connected to the first interface of the transformer 135, the second end of the first high-voltage electrolytic capacitor 165 is electrically connected to the first end of the second high-voltage electrolytic capacitor 166, the second end of the second high-voltage electrolytic capacitor 166 is grounded, the first end of the first equalizing resistor 167 is electrically connected to the first end of the first high-voltage electrolytic capacitor 165, the second end of the first equalizing resistor 167 is electrically connected to the second end of the first high-voltage electrolytic capacitor 165, the first end of the second equalizing resistor 168 is electrically connected to the second end of the first high-voltage electrolytic capacitor 165, and the second end of the second equalizing resistor 168 is grounded. By setting the high-voltage electrolytic capacitor, the self-excited oscillation generated by the feedback switch module is suppressed, thereby reducing the noise of the feedback switch module and the power consumption of the feedback switch module. By setting the equalizing resistor, the voltage of each high-voltage electrolytic capacitor is ensured to be approximately equal, thereby extending the life of the high-voltage electrolytic capacitor.

[0029] Furthermore, the feedback switching power supply module further includes a peak absorption resistor 169, a peak absorption capacitor 170, and a peak absorption diode 171, wherein a first end of the peak absorption diode 171 is electrically connected to the SW pin of the PWM controller 136, a second end of the peak absorption diode 171 is electrically connected to a first end of the peak absorption resistor 169, a second end of the peak absorption resistor 169 is electrically connected to a first interface of the transformer 135, a first end of the peak absorption capacitor 170 is electrically connected to a first end of the peak absorption resistor 169, and a second end of the peak absorption capacitor 170 is electrically connected to a peak The second end of the absorption resistor 169 is electrically connected. When the SW pin of the PWM controller 136 is turned off, the energy in the leakage inductance of the transformer 135 will be transferred to the peak absorption capacitor 170, charging the peak absorption capacitor 170, causing the voltage of the peak absorption capacitor 170 to rise. Due to the unidirectional conductivity of the peak absorption diode 171, the energy in the peak absorption capacitor 170 will then be discharged through the peak absorption resistor 169, thereby consuming the energy released by the leakage inductance, thereby protecting the circuit components from overvoltage damage and improving the reliability of the feedback switching power supply module.

[0030] Preferably, the feedback switching power supply module also includes a dummy load resistor 172, a first end of the dummy load resistor 172 is connected to the voltage input, and a second end of the dummy load resistor 172 is grounded. When there is no load in the subsequent stage, the dummy load resistor 172 provides a load, thereby ensuring voltage stability.

[0031] See next Figure 3 , Figure 3 A detection flow diagram of a fan status detection circuit provided in an embodiment of this specification is shown.

[0032] See also Figure 3 , the fan status detection method includes: S201, the fan detection module collects the voltage signal when the fan is running, and sends the voltage signal to the comparison module; S202, a comparison module generates a detection result based on the voltage signal, the detection result including whether the fan reaches a threshold value and whether the fan does not reach a threshold value; S203: When the detection result output by the comparison module indicates that the fan reaches the threshold, the alarm module outputs an alarm signal, and the protection module disconnects the feedback switch power module and the fan detection module.

[0033] In an embodiment of the present specification, the fan detection module obtains a voltage signal when the fan is running, and then sends the obtained voltage signal to the comparison module. The comparison module generates a detection result based on the voltage signal, and the detection result is that the fan reaches a threshold or the fan does not reach the threshold. When the comparison module outputs a detection result indicating that the fan reaches the threshold, the alarm module outputs an alarm signal, and the protection module disconnects the connection between the feedback switch power supply module and the fan detection module, and the fan stops rotating; when the comparison module outputs a detection result indicating that the fan does not reach the threshold, the alarm module does not operate, and the feedback switch power supply module continues to provide the power required for the operation of the entire system.

[0034] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not recorded in the present disclosure. The description and examples are regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

Claims

1. A fan status detection circuit, characterized in that: The circuit includes a feedback switch power supply module, a fan detection module, an alarm module, a comparison module and a protection module. The feedback switch power supply module is electrically connected to the protection module, the protection module is electrically connected to the comparison module, the comparison module is electrically connected to the fan detection module and the alarm module, and the fan detection module is electrically connected to the fan.

2. A fan status detection circuit according to claim 1, characterized in that: The fan detection module includes a current collection resistor and an operational amplifier, wherein a first end of the current collection resistor is electrically connected to a first end of the fan, a second end is connected to a voltage input, a second end of the fan is grounded, a first input end of the operational amplifier is electrically connected to a first end of the current collection resistor, and a second input end of the operational amplifier is electrically connected to a second end of the current collection resistor.

3. A fan status detection circuit according to claim 2, characterized in that: The comparison module includes a voltage follower and a comparator, wherein a first input terminal of the comparator is electrically connected to an output terminal of the voltage follower, and a second input terminal of the comparator is electrically connected to an output terminal of the operational amplifier.

4. A fan status detection circuit according to claim 1, characterized in that: The alarm module includes a first transistor, a first pull-up resistor and a buzzer, the first terminal of the first transistor is connected to a voltage input, the second terminal of the first transistor is electrically connected to the comparison module, the third terminal of the first transistor is electrically connected to the first terminal of the buzzer, the second terminal of the buzzer is grounded, the first terminal of the first pull-up resistor is electrically connected to the first terminal of the first transistor, and the second terminal of the first pull-up resistor is electrically connected to the second terminal of the first transistor.

5. A fan status detection circuit according to claim 4, characterized in that: The alarm module further comprises an adjusting resistor, a first end of the adjusting resistor is electrically connected to a first end of the buzzer, and a second end of the adjusting resistor is electrically connected to a second end of the buzzer.

6. A fan status detection circuit according to claim 1, characterized in that: The protection module includes a relay, a second transistor and a second pull-up resistor, the first end of the second transistor is connected to the voltage input, the second end of the second transistor is electrically connected to the comparison module, the third end of the second diode is electrically connected to the first end of the relay, the second end of the relay is electrically connected to the feedback switch power supply module, the first end of the second pull-up resistor is electrically connected to the first end of the second transistor, and the second end of the second pull-up resistor is electrically connected to the second end of the second transistor.

7. A fan status detection circuit according to claim 1, characterized in that: The feedback switching power supply module includes a winding resistor, a rectifier unit, a PWM controller and a transformer. The first end of the winding resistor is electrically connected to the protection module, the second end of the winding resistor is electrically connected to the rectifier unit, the rectifier unit is electrically connected to the PWM controller, and the PWM controller is electrically connected to the transformer.

8. A fan status detection circuit according to claim 7, characterized in that: The feedback switching power supply module also includes a first high-voltage electrolytic capacitor, a second high-voltage electrolytic capacitor, a first equalizing resistor and a second equalizing resistor. The first end of the first high-voltage electrolytic capacitor is electrically connected to the first interface of the transformer, the second end of the first high-voltage electrolytic capacitor is electrically connected to the first end of the second high-voltage electrolytic capacitor, the second end of the second high-voltage electrical capacitor is grounded, the first end of the first equalizing resistor is electrically connected to the first end of the first high-voltage electrolytic capacitor, the second end of the first equalizing resistor is electrically connected to the second end of the first high-voltage electrolytic capacitor, the first end of the second equalizing resistor is electrically connected to the second end of the first high-voltage electrolytic capacitor, and the second end of the second equalizing resistor is grounded.

9. A fan status detection circuit according to claim 7, characterized in that: The feedback switching power supply module also includes a peak absorption resistor, a peak absorption capacitor and a peak absorption diode, wherein the first end of the peak absorption diode is electrically connected to the SW pin of the PWM controller, the second end of the peak absorption diode is electrically connected to the first end of the peak absorption resistor, the second end of the peak absorption resistor is electrically connected to the first interface of the transformer, the first end of the peak absorption capacitor is electrically connected to the first end of the peak absorption resistor, and the second end of the peak absorption capacitor is electrically connected to the second end of the spike absorption resistor.

10. The fan status detection circuit according to claim 7, characterized in that: The feedback switch power supply module further includes a dummy load resistor, a first end of the dummy load resistor is connected to a voltage input, and a second end of the dummy load resistor is grounded.

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