Cooling fan fault protection circuit and impedance matcher

Abstract

The utility model belongs to the technical field of cooling fan fault protection circuits, and particularly relates to a cooling fan fault protection circuit which comprises an input circuit, an identification circuit and a switching circuit which are connected in sequence, the input circuit can obtain an alarm end signal of at least one cooling fan through an input diode, and according to the voltage division principle, the identification circuit is connected with the switching circuit. When at least one cooling fan breaks down, a second switching tube in the discriminating circuit is cut off, a first switching tube of the switching circuit is controlled to be cut off, and a driving relay is driven to be turned off, so that work of an impedance matcher driving circuit or an action circuit is cut off, and safety of personnel and equipment is protected; according to the cooling fan fault protection circuit, the alarm end signal of at least one cooling fan can be obtained at the same time, the relay is directly driven, the circuit is designed by adopting basic circuit elements and does not contain MCU software and hardware modules, and the working reliability of the protection circuit is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of heat dissipation fan fault protection circuits, and in particular relates to a heat dissipation fan fault protection circuit and an impedance matcher. Background Art

[0002] An impedance matcher is a device used to adjust the impedance matching between different parts of a circuit or system. It can match the impedance between the input and output ports by changing the components or parameters in the circuit, thereby improving the performance and efficiency of the system. The impedance matcher generates a lot of heat when working. In order to ensure normal operation, a cooling fan is required for active heat dissipation. When the cooling fan fails, the related equipment will accumulate a lot of heat, causing equipment damage.

[0003] Therefore, the working state of the cooling fan must be monitored. In the prior art, the cooling fan has its own monitoring sensor. When the cooling is blocked or in abnormal conditions, the alarm IO port of the cooling fan will flip the level. When the MCU detects the level flip, it will take corresponding protective measures to protect the safety of personnel and equipment. However, the anti-interference performance of the alarm IO port of the cooling fan is poor, and the MCU's software and hardware are relatively complex, so the stability of monitoring the abnormality of the cooling fan is poor, which can easily lead to the failure or lag of the protection measures, bringing risks to the safety of personnel and equipment. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the defect of poor stability of the heat dissipation fan fault monitoring device in the prior art, thereby providing a heat dissipation fan fault protection circuit.

[0005] The utility model discloses a heat dissipation fan fault protection circuit, comprising an input circuit, an identification circuit and a switch circuit connected in sequence; the input circuit comprises at least one input diode, the positive pole of each input diode is electrically connected to the alarm end of a heat dissipation fan, and the negative pole is electrically connected to the identification circuit; the identification circuit comprises a second switch tube and a voltage divider circuit; the voltage divider circuit is respectively connected to the input circuit and connected to the input end of the second switch tube; the switch circuit comprises a first switch tube and a relay, the input end of the first switch tube is connected to the output end of the second switch tube, and the input end of the relay is connected to the output end of the first switch tube.

[0006] Furthermore, the input circuit also includes an input resistor, the alarm end of each of the cooling fans is connected to one end of the input resistor, and the second end of the input resistor is connected to a DC power supply.

[0007] Furthermore, the voltage divider circuit of the identification circuit includes a fifth resistor, a sixth resistor and a seventh resistor, and the second switch tube is a triode; the first end of the fifth resistor is connected to a DC power supply, and the second end is connected to the first end of the sixth resistor; the second end of the sixth resistor is connected to the first end of the seventh resistor; the second end of the seventh resistor is grounded; the cathode of the input diode is connected to the first end of the seventh resistor; the emitter of the second switch tube is connected to the DC power supply, the base is connected to the second end of the fifth resistor, and the collector serves as the output end of the second switch tube.

[0008] Furthermore, the switching circuit includes a first resistor, a fourth resistor and a first diode, the first switching tube is a triode; the first end of the first resistor is connected to the output end of the second switching tube, and the second end is connected to the base of the first switching tube; the first end of the fourth resistor is connected to the output end of the second switching tube, and the second end is connected to the emitter of the first switching tube; the emitter of the first switching tube is grounded, the collector is connected to the positive electrode of the first diode, and the negative electrode of the first diode is connected to a DC power supply; the input end of the relay is connected in parallel with the first diode.

[0009] Furthermore, two input diodes are provided, which are respectively connected to the alarm terminals of the two cooling fans.

[0010] Furthermore, the alarm terminal of the cooling fan and the positive electrode of the input diode are conductively connected via a jumper wire.

[0011] Furthermore, the relay is a signal relay.

[0012] Furthermore, the first switch tube is an NPN transistor.

[0013] Furthermore, the second switch tube is a PNP transistor.

[0014] Furthermore, the input diode is a switching diode.

[0015] An impedance matcher comprises a heat dissipation fan, wherein the heat dissipation fan is connected to the heat dissipation fan fault protection circuit.

[0016] Beneficial effect: The utility model discloses a cooling fan fault protection circuit, comprising an input circuit, an identification circuit and a switch circuit connected in sequence. The input circuit can obtain the alarm end signal of at least one cooling fan through an input diode. According to the voltage division principle, when at least one cooling fan fails, the second switch tube in the identification circuit is cut off, and the first switch tube of the switch circuit is controlled to be cut off, driving the relay to turn off, thereby disconnecting the operation of the impedance matching device drive circuit or the action circuit, and protecting the safety of personnel and equipment; the cooling fan fault protection circuit of the present application can simultaneously obtain the alarm end signal of at least one cooling fan and directly drive the relay. The circuit adopts a basic circuit element design and does not include an MCU software and hardware module, thereby improving the working reliability of the protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art 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.

[0018] Figure 1 It is a schematic block diagram of the overall structure of the utility model;

[0019] Figure 2 The utility model is an overall circuit structure principle diagram.

[0020] Explanation of the accompanying drawings: K1, relay; Q1, first switch tube; Q2, second switch tube; D1, first diode; D2, input diode; P1, first jumper; P2, second jumper; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; VCC, DC power supply. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0022] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0023] In addition, in this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] Reference Figure 1 and Figure 2 As shown, this embodiment provides a cooling fan fault protection circuit, including an input circuit ①, an identification circuit ② and a switch circuit ③ connected in sequence; the input circuit includes at least one input diode D2, each of which has a positive electrode electrically connected to an alarm terminal of a cooling fan, and a negative electrode electrically connected to the identification circuit; the identification circuit includes a second switch tube Q2 and a voltage divider circuit; the voltage divider circuit is respectively connected to the input circuit and connected to the input terminal of the second switch tube Q2; the switch circuit includes a first switch tube Q1 and a relay K1, the input terminal of the first switch tube Q1 is connected to the output terminal of the second switch tube Q2, and the input terminal of the relay K1 is connected to the output terminal of the first switch tube Q1.

[0025] The present embodiment discloses a cooling fan fault protection circuit, comprising an input circuit, an identification circuit and a switch circuit connected in sequence. The input circuit can obtain an alarm terminal signal of at least one cooling fan through an input diode D2. According to the voltage division principle, when at least one cooling fan fails, the second switch tube Q2 in the identification circuit is turned off, and the first switch tube Q1 of the switch circuit is controlled to be turned off, driving the relay K1 to turn off, thereby disconnecting the operation of the impedance matching device drive circuit or the action circuit to protect the safety of personnel and equipment; the cooling fan fault protection circuit of the present application can simultaneously obtain the alarm terminal signal of at least one cooling fan and directly drive the relay K1. The circuit adopts a basic circuit element design and does not include an MCU software and hardware module, thereby improving the working reliability of the protection circuit.

[0026] Specifically, the input circuit further includes an input resistor, the alarm terminal of each cooling fan is connected to one end of the input resistor, and the second end of the input resistor is connected to the DC power supply VCC. In this embodiment, two input diodes D2 are provided, which are respectively connected to the alarm terminals IN1 and IN2 of the two cooling fans. The input diode D2 is a switching diode, and in this embodiment, the input resistor includes a second resistor R2 and a third resistor R3.

[0027] As a further improvement of this embodiment, the alarm terminal of the cooling fan and the positive electrode of the input diode D2 are conductively connected via a jumper. Specifically, the jumper includes jumper pins at both ends and jumper caps connecting the jumper pins at both ends, so that the jumper can be connected when the alarm terminal of a cooling fan needs to be monitored and can be flexibly disconnected when monitoring is not required. In this embodiment, the jumper includes a first jumper P1 and a second jumper P2.

[0028] The voltage divider circuit of the identification circuit includes a fifth resistor R5, a sixth resistor R6 and a seventh resistor R7, and the second switch tube Q2 is a triode; the first end of the fifth resistor R5 is connected to the DC power supply VCC, and the second end is connected to the first end of the sixth resistor R6; the second end of the sixth resistor R6 is connected to the first end of the seventh resistor R7; the second end of the seventh resistor R7 is grounded; the cathode of the input diode D2 is connected to the first end of the seventh resistor R7; the emitter of the second switch tube Q2 is connected to the DC power supply VCC, the base is connected to the second end of the fifth resistor R5, and the collector serves as the output end of the second switch tube Q2.

[0029] Specifically, the second switch tube Q2 is a PNP transistor.

[0030] The switch circuit includes a first resistor R1, a fourth resistor R4 and a first diode D1. The first switch tube Q1 is a triode; a first end of the first resistor R1 is connected to the output end of the second switch tube Q2, and a second end is connected to the base of the first switch tube Q1; a first end of the fourth resistor R4 is connected to the output end of the second switch tube Q2, and a second end is connected to the emitter of the first switch tube Q1; the emitter of the first switch tube Q1 is grounded, the collector is connected to the anode of the first diode D1, and the cathode of the first diode D1 is connected to the DC power supply VCC; the input end of the relay K1 is connected in parallel with the first diode D1.

[0031] Specifically, the first switch tube Q1 is an NPN transistor; the relay K1 is a signal relay.

[0032] Working principle:

[0033] When the cooling fan is working normally, the alarm terminal of the cooling fan is at a low level. At this time, there will be no reverse current at the cathode of the input diode D2. Therefore, according to the voltage division theorem, the V be The voltage is lower than -0.7V, and the second switch tube Q2 is turned on. At this time, the current flows through the second switch tube Q2, allowing Q1 to enter the saturation zone. The current passes through the relay K1 pull-in coil, and the output end of the relay K1 is connected, driving the subsequent drive circuit or action circuit to work. In some embodiments of the utility model, when the relay K1 is turned on, the cooling fan works normally, the OUT1 end and the OUT2 end are connected and turned on, so that the action circuit connected at both ends works, and the OUT1 end and the OUT2 end are used to connect to the client station and used as an alarm or display of the working status of the cooling fan; when the relay K1 is disconnected, the cooling fan works abnormally, the OUT1 end and the OUT3 end are connected, and the OUT3 end is an empty pin. At this time, the action circuit stops working. When one of the cooling fans is blocked, the level of its alarm end is pulled high. At this time, a forward current flows through the input diode D2. Due to the superposition theorem, the current of this node becomes larger, and the voltage increases, so that the V of the second switch tube Q2 be When the voltage is greater than -0.7V, the second switch tube Q2 is turned off, and when the Vbe voltage of the first switch tube Q1 is lower than 0.7V, the first switch tube Q1 is turned off, and the relay K1 is disconnected. The output end of the relay K1 is disconnected, and the subsequent drive circuit or action circuit is disconnected, thereby playing a protective role.

[0034] When both cooling fans are blocked, the alarm terminal levels of the cooling fans are pulled high, and the total current flowing through the input diode D2 is larger, so that the second switch tube Q2 is turned off, and the circuit working properties are the same as when only one cooling fan is blocked.

[0035] In some other embodiments of the present invention, the input circuit includes only one input diode D2, and is connected to an alarm terminal of a cooling fan.

[0036] In some other embodiments of the present invention, the input circuit includes more than two input diodes D2 and is connected to more than two cooling fan alarm terminals. At this time, the component parameters of the circuit are adaptively adjusted, and when at least one cooling fan alarm terminal inputs a high level, the relay K1 is driven to turn off.

[0037] This embodiment further discloses an impedance matcher, comprising a heat dissipation fan, wherein the heat dissipation fan is connected to the heat dissipation fan fault protection circuit, thereby effectively improving the heat dissipation reliability of the impedance matcher during operation.

[0038] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0039] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A cooling fan fault protection circuit, characterized in that: It includes an input circuit, an identification circuit and a switch circuit connected in sequence; the input circuit includes at least one input diode, the positive electrode of each input diode is electrically connected to the alarm end of a cooling fan, and the negative electrode is electrically connected to the identification circuit; the identification circuit includes a second switch tube and a voltage divider circuit; the voltage divider circuit is respectively connected to the input circuit and connected to the input end of the second switch tube; the switch circuit includes a first switch tube and a relay, the input end of the first switch tube is connected to the output end of the second switch tube, and the input end of the relay is connected to the output end of the first switch tube.

2. A heat dissipation fan fault protection circuit according to claim 1, characterized in that: The input circuit also includes an input resistor, the alarm end of each of the cooling fans is connected to one end of the input resistor, and the second end of the input resistor is connected to a DC power supply.

3. A heat dissipation fan fault protection circuit according to claim 1, characterized in that: The voltage divider circuit of the identification circuit includes a fifth resistor, a sixth resistor and a seventh resistor, and the second switch tube is a triode; the first end of the fifth resistor is connected to a DC power supply, and the second end is connected to the first end of the sixth resistor; the second end of the sixth resistor is connected to the first end of the seventh resistor; the second end of the seventh resistor is grounded; the cathode of the input diode is connected to the first end of the seventh resistor; the emitter of the second switch tube is connected to the DC power supply, the base is connected to the second end of the fifth resistor, and the collector serves as the output end of the second switch tube.

4. A heat dissipation fan fault protection circuit according to claim 1, characterized in that: The switching circuit includes a first resistor, a fourth resistor and a first diode, the first switching tube is a triode; the first end of the first resistor is connected to the output end of the second switching tube, and the second end is connected to the base of the first switching tube; the first end of the fourth resistor is connected to the output end of the second switching tube, and the second end is connected to the emitter of the first switching tube; the emitter of the first switching tube is grounded, the collector is connected to the positive electrode of the first diode, and the negative electrode of the first diode is connected to a DC power supply; the input end of the relay is connected in parallel with the first diode.

5. A heat dissipation fan fault protection circuit according to claim 1, characterized in that: Two input diodes are provided and are respectively connected to the alarm terminals of the two cooling fans.

6. A heat dissipation fan fault protection circuit according to claim 1, characterized in that: The alarm terminal of the heat dissipation fan and the positive electrode of the input diode are conductively connected via a jumper wire.

7. A heat dissipation fan fault protection circuit according to claim 1, characterized in that: The relay is a signal relay.

8. A heat dissipation fan fault protection circuit according to claim 1, characterized in that: The first switch tube is an NPN transistor.

9. A heat dissipation fan fault protection circuit according to claim 1, characterized in that: The second switch tube is a PNP type transistor.

10. A heat dissipation fan fault protection circuit according to claim 1, characterized in that: The input diode is a switching diode.

11. An impedance matching device, characterized in that: It comprises a cooling fan, and the cooling fan is connected to the cooling fan fault protection circuit according to any one of claims 1 to 10.

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