Monitoring circuit, heat dissipation device and complete machine system

Abstract

The utility model relates to the technical field of electronic circuits, and discloses a monitoring circuit, a heat dissipation device and a complete machine system.The monitoring circuit comprises a power conversion module, a logic output module, a first switch module, a second switch module, an IO board card module and a display module; the power supply conversion module converts power supply voltage into voltage required when the fan works, and the logic output module outputs a first level signal according to the level state of a feedback signal of the fan; the first switch module outputs a second level signal to the second switch module according to the level state of the first level signal; the second switch module is switched off or switched on according to the output voltage of the power supply conversion module and the level state of the second level signal, and outputs a third level signal to the IO board card module; the display module prompts the working state of the fan according to the level state of the third level signal. The monitoring circuit can monitor the working state of the fan in the heat dissipation device, and the heat dissipation device reduces the fault occurrence rate of a whole machine system.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a monitoring circuit, a heat dissipation device and a complete system. Background Art

[0002] The LCU system generates a lot of heat and the board fails frequently. The main reason is that the electronic equipment in the LCU system generates heat when working. Long-term operation makes the LCU system affected by the heat load, which leads to hardware problems in the LCU system, such as aging and damage of components, cracking of welding points, etc. The high failure rate of the board will also reduce the service life of the LCU system. In order to solve this problem, a heat dissipation device is usually added to the LCU system. However, if the damage of the cooling fan in the heat dissipation device is not discovered in time, it will cause the heat dissipation problem of the LCU system again, thus affecting the normal operation of the LCU system. Utility Model Content

[0003] In view of this, the embodiments of the present application provide a monitoring circuit, a heat dissipation device and a complete system, which realize a heat dissipation device with a function of monitoring the working status of a fan, and can effectively solve the heat dissipation problem of the LCU complete system.

[0004] In a first aspect, an embodiment of the present application provides a monitoring circuit for monitoring the status of a heat dissipation device, wherein the heat dissipation device includes a plurality of fans, and the monitoring circuit includes a power conversion module, a logic output module, a first switch module, a second switch module, an IO board module, and a display module;

[0005] The power conversion module is used to convert the power supply voltage into the voltage required when the fan is working;

[0006] The logic output module is used to electrically connect each of the fans to receive feedback signals from each of the fans, and output a first level signal of a corresponding level state according to the level state of each of the feedback signals;

[0007] The first switch module is used to electrically connect to the logic output module to be turned on or off according to the level state of the first level signal, and output a second level signal of a different level state to the second switch module;

[0008] The second switch module is used to electrically connect the power conversion module to cut off or conduct according to the output voltage of the power conversion module and the level state of the second level signal, and output a third level signal of a different level state to the IO board module;

[0009] The display module is used to be electrically connected to the IO board module to indicate the working state of the fan according to the level state of the third level signal recognized by the IO board module.

[0010] In a first possible embodiment of the first aspect, the logic output module is further used to output the first level signal in a first level state when at least one of the feedback signals is in a level state indicating a fan failure;

[0011] The logic output module is further configured to output the first level signal in a second level state when each of the feedback signals is in a level state indicating that the fan is working normally.

[0012] In a second possible embodiment of the first aspect, a protection module is also included;

[0013] The protection module is used to be electrically connected to the power conversion module so as to automatically cut off the monitoring circuit when the monitoring circuit is short-circuited.

[0014] In a third possible embodiment of the first aspect, the protection module includes a fuse and a power resistor;

[0015] The first end of the fuse is used to connect to the power supply, the second end of the fuse is respectively connected to the first end of the power resistor and the input end of the power conversion module, and the second end of the power resistor is used to connect the series node of the first optocoupler isolator and the second optocoupler isolator.

[0016] In a fourth possible embodiment of the first aspect, the first switch module further includes a first current limiting resistor and a first optocoupler isolator, and the second switch module further includes a second current limiting resistor and a second optocoupler isolator;

[0017] The first end of the first current limiting resistor is used to connect the logic output module, the second end of the first current limiting resistor is used to connect the first end of the first optocoupler isolator, the second end of the first optocoupler isolator is used to connect the power conversion module, the third end of the first optocoupler isolator is used to connect the third end of the second optocoupler isolator, and the fourth end of the first optocoupler isolator is grounded;

[0018] The first end of the second current limiting resistor is used to connect to the power conversion module, the second end of the second current limiting resistor is used to connect to the first end of the second optocoupler isolator, the second end of the second optocoupler isolator is used to connect to the power conversion module, and the fourth end of the second optocoupler isolator is used to connect to the IO board module.

[0019] In a fifth possible embodiment of the first aspect, the power conversion module includes a first diode, a first capacitor, a second capacitor, a voltage converter, a third current limiting resistor, a first display light, a fourth current limiting resistor, and a second display light;

[0020] The anode of the first diode is connected to the second end of the fuse, the cathode of the first diode is connected to the first end of the first capacitor, and the second end of the first capacitor is used to connect to the negative electrode of the power supply;

[0021] A first end of the voltage converter is connected to a series node of the first diode and the first capacitor, a second end of the voltage converter is connected to a second end of the first capacitor, a third end of the voltage converter is connected to a first end of the second capacitor, and a fourth end of the voltage converter is connected to a second end of the second capacitor;

[0022] The first end of the third current limiting resistor is connected to the first end of the voltage converter, the second end of the third current limiting resistor is connected to the first end of the first display light, and the second end of the first display light is connected to the second end of the voltage converter; the first end of the fourth current limiting resistor is connected to the third end of the voltage converter, the second end of the fourth current limiting resistor is connected to the first end of the second display light, and the second end of the second display light is connected to the fourth end of the voltage converter.

[0023] In a sixth possible embodiment of the first aspect, the logic output module includes a plurality of basic units; each of the basic units is used to connect each of the fans, and a parallel node of each of the basic units is used to connect the first switch module.

[0024] In a seventh possible embodiment of the first aspect, each of the basic units includes a fifth current limiting resistor and a second diode;

[0025] The first end of the fifth current limiting resistor is used to connect to the power conversion module, the second end of the fifth current limiting resistor is connected to the anode of the second diode, the cathode of the second diode is used to connect to the first switch module, and each series node of the fifth current limiting resistor and the second diode is used to connect each of the fans.

[0026] In a second aspect, an embodiment of the present application provides a heat dissipation device, comprising a plurality of fans and the above-mentioned monitoring circuit.

[0027] In a third aspect, an embodiment of the present application provides a complete system, including the above-mentioned heat dissipation device.

[0028] The embodiments of the present application have the following beneficial effects:

[0029] A monitoring circuit of the present embodiment is used for monitoring the status of a heat dissipation device, the heat dissipation device includes a plurality of fans, and the monitoring circuit includes a power conversion module, a logic output module, a first switch module, a second switch module, an IO board module and a display module; the power conversion module is used to convert the power supply voltage into the voltage required when the fan is working; the logic output module is used to electrically connect each fan to receive the feedback signal of each fan, and output a first level signal of a corresponding level state according to the level state of each feedback signal; the first switch module is used to electrically connect the logic output module to conduct or cut off according to the level state of the first level signal, and output a second level signal of a different level state to the second switch module; the second switch module is used to electrically connect the power conversion module to cut off or conduct according to the output voltage of the power conversion module and the level state of the second level signal, and output a third level signal of a different level state to the IO board module; the display module is used to electrically connect the IO board module to prompt the working status of the fan according to the level state of the third level signal recognized by the IO board module. Based on the above scheme, the monitoring circuit can accurately identify and judge the working status of the fan in the heat dissipation device. The heat dissipation device with monitoring function can significantly reduce the temperature of the internal components of the LCU system, thereby effectively reducing the failure rate of the board in the LCU system and improving the service life of the LCU system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A framework scene diagram of a heat dissipation device according to an embodiment of the present application is shown;

[0032] Figure 2 A first structural schematic diagram of the monitoring circuit according to an embodiment of the present application is shown;

[0033] Figure 3 A second structural schematic diagram of the monitoring circuit according to an embodiment of the present application is shown;

[0034] Figure 4 A schematic diagram of the circuit structure of the monitoring circuit of an embodiment of the present application is shown;

[0035] Figure 5 A schematic diagram of the circuit structure of the first switch module in an embodiment of the present application is shown;

[0036] Figure 6A schematic diagram of the circuit structure of a power conversion module according to an embodiment of the present application is shown;

[0037] Figure 7 A schematic diagram of the circuit structure of the logic output module of an embodiment of the present application is shown.

[0038] Description of main component symbols:

[0039] 10-heat dissipation device; 11-fan; 100-monitoring circuit; 110-power conversion module; 120-logic output module; 130-first switch module; 140-second switch module; 150-IO board module; 160-display module; 170-protection module. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0041] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0042] Hereinafter, the terms "including", "having" and their cognates that can be used in various embodiments of the present application are intended only to indicate specific features, numbers, steps, operations, elements, components or a combination of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or a combination of the foregoing items or increasing the possibility of one or more features, numbers, steps, operations, elements, components or a combination of the foregoing items. In addition, the terms "first", "second", "third" and the like are only used to distinguish descriptions and cannot be understood as indicating or implying relative importance.

[0043] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meanings as those generally understood by those skilled in the art to which the various embodiments of the present application belong. Terms (such as those defined in generally used dictionaries) will be interpreted as having the same meanings as the contextual meanings in the relevant technical field and will not be interpreted as having idealized meanings or overly formal meanings unless clearly defined in the various embodiments of the present application.

[0044] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0045] Please refer to Figure 1 , is a heat sink 10 with the function of monitoring its own working state proposed in an embodiment of the present application, and the heat sink 10 includes a plurality of fans 11. Based on the structure of the heat sink 10 described above, an embodiment of the present application proposes a monitoring circuit 100, which can be used to monitor the working state of each fan 11 in the heat sink 10, and perform logic processing according to the feedback signal of each fan 11. When one of the fans 11 fails, it can promptly prompt that there is a fan failure in the heat sink 10. The monitoring circuit 100 is described in detail below.

[0046] Please refer to Figure 2 , is a schematic diagram of a structure of a monitoring circuit 100 proposed in an embodiment of the present application. Exemplarily, the monitoring circuit 100 includes a power conversion module 110, a logic output module 120, a first switch module 130, a second switch module 140, an IO board module 150 and a display module 160. Specifically, as Figure 3 As shown, the monitoring circuit 100 further includes a protection module 170 , which is connected to the input end of the power conversion module 110 , so as to cut off the monitoring circuit 100 for protection when a short circuit occurs in the monitoring circuit 100 .

[0047] In this embodiment, the power conversion module 110 is used to convert the power supply voltage into the voltage required when the fan 11 is working; the logic output module 120 is used to electrically connect each fan 11 to receive the feedback signal of each fan 11, and output the first level signal of the corresponding level state according to the level state of each feedback signal; the first switch module 130 is used to electrically connect the logic output module 120 to be turned on or off according to the level state of the first level signal, and output the second level signal of a different level state to the second switch module 140; the second switch module 140 is used to electrically connect the power conversion module 110 to be turned off or on according to the output voltage of the power conversion module 110 and the level state of the second level signal, and output the third level signal of a different level state to the IO board module 150; the display module 160 is used to electrically connect the IO board module 150 to indicate the working state of the fan 11 according to the level state of the third level signal recognized by the IO board module 150.

[0048] It can be understood that the monitoring circuit 100 is used to turn on or off the first switch module 130 according to the feedback signal of each fan 11, so as to output the second level signal of different level states; the monitoring circuit 100 is also used to turn on or off the second switch module 140 according to the judgment result of whether the power conversion module 110 has voltage output and the level state of the second level signal, so as to output the third level signal of different level states; the monitoring circuit is also used to make the display module 160 indicate the working state of the fan in different display states according to the level state of the third level signal. When the power supply voltage is too high, the power conversion module 110 is used to convert the power supply voltage into the voltage required for the fan 11 to work, so as to ensure that the fan 11 can obtain stable and appropriate power supply, so as to maintain its continuous and stable operation.

[0049] Exemplarily, the logic output module 120 is used to output a first level signal in a first level state to the second switch module 140 when one or more fans 11 fail. The logic output module 120 is also used to output a first level signal in a second level state to the second switch module 140 when all fans 11 are operating normally.

[0050] For example, in one embodiment, the logic output module 120 is also used to output a first level signal in a first level state when at least one of the feedback signals is in a level state indicating a failure of the fan 11; the logic output module 120 is also used to output a first level signal in a second level state when all the feedback signals are in a level state indicating that the fan 11 is working normally.

[0051] Exemplarily, the first switch module 130 is used to cut off according to the first level signal of the first level state to output the second level signal of the third level state; the first switch module 130 is also used to conduct according to the second level signal of the second level state to output the second level signal of the fourth level state. When the power conversion module 110 is not faulty, the second switch module 140 is used to output the third level signal of the fifth level state according to the second level signal of the third level state, so that the display module 160 prompts that the fan 11 is not in the working state according to the third level signal of the fifth level state, and the second switch module 140 is also used to output the third level signal of the sixth level state according to the second level signal of the fourth level state, so that the display module 160 prompts that the fan 11 is in the working state according to the third level signal of the sixth level state. When the power conversion module 110 is faulty, the second switch module 140 is also used to output the third level signal of the fifth level state, so that the display module 160 prompts that the power conversion module 110 is faulty according to the third level signal of the fifth level state.

[0052] It can be understood that the descriptions of "first", "second" and "third" in the above-mentioned first level signal, second level signal and third level signal are only for distinguishing different conduction signals generated by different circuits in different situations. Similarly, the first level state and the second level state of the first level signal, the third level state and the fourth level state of the second level signal, the fifth level state and the sixth level state of the third level signal, the descriptions of "first", "second", "third", "fourth", "fifth" and "sixth" therein are only for distinguishing the first level signal, the second level signal and the third level signal in high level or low level state.

[0053] In order to better understand the monitoring circuit 100, the various components of the monitoring circuit 100 are described in detail below. Figure 4 , is a circuit diagram of the monitoring circuit 100 proposed in an embodiment of the present application.

[0054] In one embodiment, the protection module 170 includes a fuse L1 and a power resistor R0; the first end of the fuse L1 is used to connect to a power source, the second end of the fuse L1 is respectively connected to the first end of the power resistor R0 and the input end of the power conversion module 110, and the second end of the power resistor R0 is used to connect to the series node of the first optocoupler isolator D1 and the second optocoupler isolator D2.

[0055] In this embodiment, the fuse L1 is an electrical safety device used to protect the monitoring circuit 100 or the heat sink 10 from damage caused by current overload or short circuit. The fuse L1 is composed of components such as fuses or thermistors. When the current in the monitoring circuit 100 is overloaded or short-circuited, the current in the monitoring circuit 100 will increase rapidly, causing the thermistor components inside the fuse L1 to be heated, thereby changing its resistance value or causing the fuse to melt, so as to disconnect the power supply of the monitoring circuit 100, thereby preventing the heat sink 10 from being damaged or fire and other safety accidents.

[0056] like Figure 5As shown, in one embodiment, the first switch module 130 also includes a first current limiting resistor R1 and a first optocoupler isolator D1, and the second switch module 140 also includes a second current limiting resistor R2 and a second optocoupler isolator D2; the first end of the first current limiting resistor R1 is used to connect to the logic output module 120, the second end of the first current limiting resistor R1 is used to connect to the first end of the first optocoupler isolator D1, the second end of the first optocoupler isolator D2 is used to connect to the power conversion module 110, the third end of the first optocoupler isolator D1 is used to connect to the third end of the second optocoupler isolator D2, and the fourth end of the first optocoupler isolator D1 is grounded GND; the first end of the second current limiting resistor R2 is used to connect to the power conversion module 110, the second end of the second current limiting resistor R2 is used to connect to the first end of the second optocoupler isolator D2, the second end of the second optocoupler isolator D2 is used to connect to the power conversion module 110, and the fourth end of the second optocoupler isolator D2 is used to connect to the IO board module 150.

[0057] In this embodiment, the first switch module 130 isolates the first level signal through the first optocoupler isolator D1, and the first optocoupler isolator D1 is used to convert the input first level signal into an optical signal, so as to achieve the purpose of electrical isolation; the first optocoupler isolator D1 is also used to conduct or cut off according to the different level states of the first level signal to output the second level signal of different level states. The second switch module 140 isolates the output voltage and the second level signal of the power conversion module 110 through the second optocoupler isolator D2. When the output voltage reaches the conduction voltage of the second optocoupler isolator D2, the second optocoupler isolator D2 is used to cut off according to the second level signal of the third level state, and the second optocoupler isolator D2 is also used to conduct according to the second level signal of the fourth level state. When the output voltage does not reach the conduction voltage of the second optocoupler isolator D2, the second optocoupler isolator D2 is in the cut-off state. It can be understood that the first switch module 130 and the second switch module 140 ensure the safety and stability of the monitoring circuit 100 by isolating the input and output signals, and reduce the influence of current and voltage on the heat dissipation device 10.

[0058] like Figure 6As shown, in one embodiment, the power conversion module 110 includes a first diode D3, a first capacitor C1, a second capacitor C2, a voltage converter U1, a third current limiting resistor R3, a first display light LED1, a fourth current limiting resistor R4, and a second display light LED2; the anode of the first diode D3 is connected to the second end of the fuse L1, the cathode of the first diode D3 is connected to the first end of the first capacitor C1, and the second end of the first capacitor C1 is used to connect to the negative electrode of the power supply; the first end of the voltage converter U1 is connected to the series node of the first diode D3 and the first capacitor C1, and the second end of the voltage converter U1 is connected to the second end of the first capacitor C1 , the third end of the voltage converter U1 is connected to the first end of the second capacitor C2, and the fourth end of the voltage converter U1 is connected to the second end of the second capacitor C2; the first end of the third current limiting resistor R3 is connected to the first end of the voltage converter U1, the second end of the third current limiting resistor R3 is connected to the first end of the first display light LED1, and the second end of the first display light LED1 is connected to the second end of the voltage converter U1; the first end of the fourth current limiting resistor R4 is connected to the third end of the voltage converter U1, the second end of the fourth current limiting resistor R4 is connected to the first end of the second display light LED2, and the second end of the second display light LED2 is connected to the fourth end of the voltage converter U1.

[0059] In this embodiment, the first display light LED1 is used to light up when there is voltage at the input end of the voltage converter U1; when there is no voltage at the input end of the voltage converter U1, the display light is off. The second display light LED2 is used to light up when there is voltage at the output end of the voltage converter U1; when there is no voltage at the output end of the voltage converter U1, the display light is off.

[0060] like Figure 7 As shown, in one embodiment, the logic output module 120 includes a plurality of basic units; each basic unit is used to connect each fan 11, and the parallel node of each basic unit is used to connect the first switch module 130. Each basic unit includes a fifth current limiting resistor R5 and a second diode D4; the first end of the fifth current limiting resistor R5 is used to connect the power conversion module 110, the second end of the fifth current limiting resistor R5 is connected to the anode of the second diode D2, the cathode of the second diode D4 is used to connect the first switch module 130, and the series node of each fifth current limiting resistor R5 and the second diode D4 is used to connect each fan.

[0061] In this embodiment, the logic output module 120 includes multiple input terminals and one output terminal, each input terminal is connected to each fan 11 to receive the feedback signal of each fan 11, and the logic output module 120 outputs a first level signal of the corresponding level state through the output terminal according to the level state of each feedback signal.

[0062] Exemplarily, the display module 160 can be an indicator light. For example, when the power conversion module 110 fails and the output voltage is zero, the indicator light is in an off state; when the output voltage of the power conversion module 110 is normal, the IO board module 150 inputs a third level signal in a fifth level state, and the indicator light is in an off state; when the output voltage of the power conversion module 110 is normal, the IO board module 150 inputs a third level signal in a sixth level state, and the indicator light is in a lit state.

[0063] It should be understood that the monitoring circuit 100 of the present embodiment can exist in the form of a separate packaged circuit module, or can be a part of the above-mentioned heat dissipation device 10, that is, arranged inside the heat dissipation device 10, which is not limited here. For example, the present application embodiment also proposes a heat dissipation device 10, which exemplarily includes a plurality of fans 11 and the monitoring circuit 100 of the above-mentioned embodiment, and the input end of the monitoring circuit 100 is connected to the outlet end of each fan 11 in the heat dissipation device 10; wherein the monitoring circuit 100 is used to monitor the working state of the fan 11 in the heat dissipation device 10, and when a fan 11 fault is detected, it prompts that the fan 11 has a fault.

[0064] The present application also proposes a complete system, which may be an LCU industrial control system device, a logic controller, a power supply device, etc. Exemplarily, the complete system includes a heat dissipation device 10 and a monitoring circuit 100 in the above embodiment, wherein the monitoring circuit 100 may be integrated into the heat dissipation device 10.

[0065] The above are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be covered by the protection scope of the present application.

Claims

1. A monitoring circuit, characterized in that: Used to monitor the status of a heat dissipation device, wherein the heat dissipation device includes a plurality of fans, and the monitoring circuit includes a power conversion module, a logic output module, a first switch module, a second switch module, an IO board module and a display module; The power conversion module is used to convert the power supply voltage into the voltage required when the fan is working; The logic output module is used to electrically connect each of the fans to receive feedback signals from each of the fans, and output a first level signal of a corresponding level state according to the level state of each of the feedback signals; The first switch module is used to electrically connect to the logic output module to be turned on or off according to the level state of the first level signal, and output a second level signal of a different level state to the second switch module; The second switch module is used to electrically connect the power conversion module to cut off or conduct according to the output voltage of the power conversion module and the level state of the second level signal, and output a third level signal of a different level state to the IO board module; The display module is used to be electrically connected to the IO board module to indicate the working state of the fan according to the level state of the third level signal recognized by the IO board module.

2. The monitoring circuit according to claim 1, characterized in that: The logic output module is further configured to output the first level signal in a first level state when at least one of the feedback signals is in a level state indicating a fan failure; The logic output module is further configured to output the first level signal in a second level state when each of the feedback signals is in a level state indicating that the fan is working normally.

3. The monitoring circuit according to claim 1, characterized in that: Also includes protection modules; The protection module is used to be electrically connected to the power conversion module so as to automatically cut off the monitoring circuit when the monitoring circuit is short-circuited.

4. The monitoring circuit according to claim 3, characterized in that: The protection module includes a fuse and a power resistor; The first end of the fuse is used to connect to the power supply, the second end of the fuse is respectively connected to the first end of the power resistor and the input end of the power conversion module, and the second end of the power resistor is used to connect the series node of the first optocoupler isolator and the second optocoupler isolator.

5. The monitoring circuit according to claim 1, characterized in that: The first switch module further includes a first current limiting resistor and a first optocoupler isolator, and the second switch module further includes a second current limiting resistor and a second optocoupler isolator; The first end of the first current limiting resistor is used to connect the logic output module, the second end of the first current limiting resistor is used to connect the first end of the first optocoupler isolator, the second end of the first optocoupler isolator is used to connect the power conversion module, the third end of the first optocoupler isolator is used to connect the third end of the second optocoupler isolator, and the fourth end of the first optocoupler isolator is grounded; The first end of the second current limiting resistor is used to connect to the power conversion module, the second end of the second current limiting resistor is used to connect to the first end of the second optocoupler isolator, the second end of the second optocoupler isolator is used to connect to the power conversion module, and the fourth end of the second optocoupler isolator is used to connect to the IO board module.

6. The monitoring circuit according to claim 4, characterized in that: The power conversion module includes a first diode, a first capacitor, a second capacitor, a voltage converter, a third current limiting resistor, a first display light, a fourth current limiting resistor and a second display light; The anode of the first diode is connected to the second end of the fuse, the cathode of the first diode is connected to the first end of the first capacitor, and the second end of the first capacitor is used to connect to the negative electrode of the power supply; A first end of the voltage converter is connected to a series node of the first diode and the first capacitor, a second end of the voltage converter is connected to a second end of the first capacitor, a third end of the voltage converter is connected to a first end of the second capacitor, and a fourth end of the voltage converter is connected to a second end of the second capacitor; The first end of the third current limiting resistor is connected to the first end of the voltage converter, the second end of the third current limiting resistor is connected to the first end of the first display light, and the second end of the first display light is connected to the second end of the voltage converter; the first end of the fourth current limiting resistor is connected to the third end of the voltage converter, the second end of the fourth current limiting resistor is connected to the first end of the second display light, and the second end of the second display light is connected to the fourth end of the voltage converter.

7. The monitoring circuit according to claim 1, characterized in that: The logic output module includes a plurality of basic units; each of the basic units is used to connect to each of the fans, and the parallel nodes of the basic units are used to connect to the first switch module.

8. The monitoring circuit according to claim 7, characterized in that: Each of the basic units includes a fifth current limiting resistor and a second diode; The first end of the fifth current limiting resistor is used to connect to the power conversion module, the second end of the fifth current limiting resistor is connected to the anode of the second diode, the cathode of the second diode is used to connect to the first switch module, and each series node of the fifth current limiting resistor and the second diode is used to connect each of the fans.

9. A heat dissipation device, characterized in that: The invention comprises a plurality of fans and a monitoring circuit as claimed in any one of claims 1 to 8.

10. A complete system, characterized in that: Comprising the heat dissipation device as claimed in claim 9.

Images