Fan operation detection circuit

Abstract

The utility model provides a fan operation detection circuit. The fan operation detection circuit comprises an optocoupler, an electrolytic capacitor C2 and an IO detection module, a primary side light emitting diode of the optocoupler is connected between an input power supply of the fan and the ground through an electrolytic capacitor C2, a secondary side triode of the optocoupler is connected between power supply voltage and the ground, and the IO detection module is used for detecting the level input to the IO detection module by the secondary side triode of the optocoupler; when the draught fan operates normally, the level input by the IO detection module is high-low level changing periodically. And when the fan runs abnormally, the level input by the IO detection module is a continuous high level.

Description

Technical Field

[0001] The utility model relates to a fan operation detection circuit. Background Art

[0002] Fans are devices used for heat dissipation. Various devices that generate a lot of heat during operation need to use fans for heat dissipation, such as power cabinets, chemical distribution cabinets and other equipment. When the fan cannot operate normally, it will directly affect the stability of the corresponding equipment. Therefore, it is necessary to grasp the operating status of the fan in real time.

[0003] However, traditionally, the operating status of the fan can only be judged by the naked eye, or by the human body's sense of whether the air is coming out. When the fan is installed in a hidden location, it will be difficult to quickly determine the operating status. When there are a large number of fans, regular manual inspections are required, which is not only inefficient but also consumes a lot of manpower costs.

[0004] Therefore, how to provide a fan status detection device to automatically detect the operating status of the fan has become a technical problem that needs to be solved urgently.

[0005] In order to solve this problem in the prior art, the commonly used fan stall detection methods are as follows: 1. Relying on the fan speed feedback signal. Fans with speed feedback are expensive, and the feedback signal output method is an OC gate. The current pulling capabilities of different fans vary greatly, which increases the design difficulty; 2. By measuring the operating current of the fan during operation, it is determined whether the fan is stalled. This method has a complex circuit and high cost. Utility Model Content

[0006] The main technical problem to be solved by the utility model is to provide a fan operation detection circuit, which can realize automatic judgment of the fan operation state, and the circuit is simple and low in cost.

[0007] In order to solve the above technical problems, the utility model provides a fan operation detection circuit, including: an optical coupler, an electrolytic capacitor C2 and an IO detection module;

[0008] The primary light emitting diode of the optocoupler is connected between the input power supply of the fan and the ground through the electrolytic capacitor C2, the secondary transistor of the optocoupler is connected between the power supply voltage and the ground, and the IO detection module is used to detect the level of the secondary transistor of the optocoupler input to the IO detection module;

[0009] When the fan operates normally, the level input to the IO detection module is a high and low level that changes periodically; when the fan operates abnormally, the level input to the IO detection module is a continuous high level.

[0010] In a preferred embodiment: an electrolytic capacitor C1 is connected between the input power supply and the ground.

[0011] In a preferred embodiment: the anode of the primary light emitting diode is connected to the positive electrode of the input power supply through the electrolytic capacitor C2, and the cathode is connected to the negative electrode of the input power supply.

[0012] In a preferred embodiment: the primary light emitting diode is connected in parallel with the resistor R1.

[0013] In a preferred embodiment: the collector of the secondary transistor is connected to the power supply voltage through the resistor R2, and the emitter is grounded.

[0014] In a preferred embodiment: the IO detection module is connected to the power supply voltage through resistors R3 and R2, and is grounded through capacitor C3.

[0015] Compared with the prior art, the technical solution of the utility model has the following beneficial effects:

[0016] The utility model provides a fan operation detection circuit. After the power supply device controls the fan to start, when the fan is operating normally, a ripple current with alternating current will be generated on the capacitor C2. The signal is collected and photoelectrically converted through the signal acquisition circuit resistor R1, capacitor C2, and optocoupler IC1. When the fan is running, the primary light-emitting diode of the optocoupler IC1 follows the ripple current to conduct and cut off, and the secondary voltage of the optocoupler IC1 is periodically pulled down. The secondary level state of the optocoupler IC1 is connected to the IO input end of the IO detection module through the detection circuit resistor R2, resistor R3, and capacitor C3. The IO detection module determines the operation of the fan by detecting the IO port level state. When the IO port detects a high-low level change, it indicates that the fan is operating normally. If the fan is blocked, no ripple current flows through the capacitor C2, the primary light-emitting diode of the optocoupler IC1 is in a cut-off state, and the secondary side of the optocoupler IC1 is a normally high voltage. The IO detection module detects that the IO port input voltage is normally high and the level does not change, indicating that the fan is blocked. Thereby, automatic detection of the operating status of the fan is achieved, and the circuit structure is very simple and the cost is relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A circuit diagram of a preferred embodiment of the utility model;

[0018] Figure 2 It is a current waveform diagram of the electrolytic capacitor C2 and a level diagram of the IO detection module when the fan is operating normally in the preferred embodiment of the utility model. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model; it is obvious that the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the utility model without making creative work are within the scope of protection of the utility model.

[0020] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships described in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0021] In the description of the present utility model, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "installed / connected", "connected", etc. should be understood in a broad sense. For example, "connection" can be a wall-mounted 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 components. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to specific circumstances.

[0022] refer to Figure 1 and Figure 2 ,This embodiment provides a fan operation detection circuit, including: an optical coupler and an IO detection module;

[0023] The primary light emitting diode of the optocoupler is connected between the input power supply of the fan and the ground, the secondary transistor of the optocoupler is connected between the power supply voltage and the ground, and the IO detection module is used to detect the level of the secondary transistor of the optocoupler input to the IO detection module;

[0024] When the fan operates normally, the level input to the IO detection module is a high and low level that changes periodically; when the fan operates abnormally, the level input to the IO detection module is a continuous high level.

[0025] In order to achieve the above detection, in this embodiment, an electrolytic capacitor C1 is connected between the input power supply and the ground. The anode of the primary light emitting diode is connected to the positive electrode of the input power supply through the electrolytic capacitor C2, and the cathode is connected to the negative electrode of the input power supply. In addition, the primary light emitting diode is connected in parallel with the resistor R1.

[0026] In addition, the collector of the secondary transistor is connected to the power supply voltage through the resistor R2, and the emitter is grounded. The IO detection module is connected to the power supply voltage through the resistors R3 and R2, and is grounded through the capacitor C3.

[0027] In the above-mentioned fan operation detection circuit, after the power supply device controls the fan to start, when the fan is operating normally, a ripple current with alternating current will be generated on the capacitor C2, which is collected and photoelectrically converted through the signal acquisition circuit resistor R1, capacitor C2, and optocoupler IC1. When the fan is running, the primary light-emitting diode of the optocoupler IC1 follows the ripple current to turn on and off, and the secondary voltage of the optocoupler IC1 is periodically pulled down. The secondary level state of the optocoupler IC1 is connected to the IO input end of the IO detection module through the detection circuit resistor R2, resistor R3, and capacitor C3. The IO detection module determines the operation of the fan by detecting the IO port level state. When the IO port detects a high-low level change, it indicates that the fan is operating normally. If the fan is blocked, no ripple current flows through the capacitor C2, the primary light-emitting diode of the optocoupler IC1 is in the cut-off state, and the secondary side of the optocoupler IC1 is a normally high voltage. The IO detection module detects that the IO port input voltage is normally high and the level does not change, indicating that the fan is blocked. Thereby, automatic detection of the operating status of the fan is achieved, and the circuit structure is very simple and the cost is relatively low.

[0028] The above is only a preferred specific implementation method of the utility model, but the design concept of the utility model is not limited to this. Any technician familiar with the technical field who uses this concept to make non-substantial changes to the utility model within the technical scope disclosed by the utility model shall be deemed to infringe the protection scope of the utility model.

Claims

1. The fan operation detection circuit is characterized by include: Optocoupler, electrolytic capacitor C2 and IO detection module; The primary light emitting diode of the optocoupler is connected between the input power supply of the fan and the ground through the electrolytic capacitor C2, the secondary transistor of the optocoupler is connected between the power supply voltage and the ground, and the IO detection module is used to detect the level of the secondary transistor of the optocoupler input to the IO detection module; When the fan operates normally, the level input to the IO detection module is a high and low level that changes periodically; when the fan operates abnormally, the level input to the IO detection module is a continuous high level.

2. The fan operation detection circuit according to claim 1 is characterized in that: An electrolytic capacitor C1 is connected between the input power supply and the ground.

3. The fan operation detection circuit according to claim 1 is characterized in that: The anode of the primary light emitting diode is connected to the positive electrode of the input power supply through the electrolytic capacitor C2, and the cathode is connected to the negative electrode of the input power supply.

4. The fan operation detection circuit according to claim 3 is characterized in that: The primary light emitting diode is connected in parallel with the resistor R1.

5. The fan operation detection circuit according to claim 1 is characterized in that: The collector of the secondary transistor is connected to the power supply voltage through the resistor R2, and the emitter is grounded.

6. The fan operation detection circuit according to claim 5, characterized in that: The IO detection module is connected to the power supply voltage through resistors R3 and R2, and is grounded through capacitor C3.

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