AC fan operation state monitoring circuit

Abstract

The invention relates to an alternating current fan running state monitoring circuit. The circuit comprises a sampling module connected with an alternating current fan in series, an amplifying module connected with the sampling module and a controller connected with the amplifying module. The sampling module is used for collecting a first voltage signal corresponding to the alternating current fan and sending the collected first voltage signal to the amplification module; the amplification module is used for amplifying the first voltage signal to obtain a second voltage signal in a preset voltage range; and the controller is used for calculating the actual power of the alternating current fan based on the second voltage signal and determining the running state of the alternating current fan based on the actual power.

Description

Technical Field

[0001] The present application relates to the field of circuit technology, and in particular to an AC fan operating status monitoring circuit. Background Art

[0002] The ordinary fan circuit has only one switch. When the switch is closed, the fan starts, and when the switch is open, the fan stops. The controller can only control the fan to power on or off through the switch, but it is completely unable to understand the actual operating status of the fan. There is an urgent need for a way to detect the operating status of the fan. Summary of the invention

[0003] Based on this, it is necessary to provide an AC fan operating status monitoring circuit that can detect the operating status of the fan in order to solve the above technical problems.

[0004] In a first aspect, the present application provides an AC fan operation status monitoring circuit, comprising:

[0005] In some embodiments, an AC fan operating status monitoring circuit includes: a sampling module connected in series with the AC fan, an amplification module connected to the sampling module, and a controller connected to the amplification module;

[0006] The sampling module is used to collect the first voltage signal corresponding to the AC fan and send the collected first voltage signal to the amplification module;

[0007] The amplification module is used to amplify the first voltage signal to obtain a second voltage signal within a preset voltage range;

[0008] The controller is used to calculate the actual power of the AC fan based on the second voltage signal, and determine the operating state of the AC fan based on the actual power.

[0009] In some embodiments, the sampling module includes: a current acquisition unit and a current conversion unit, wherein a first input end of the current acquisition unit is connected to the AC fan, a second input end of the current acquisition unit is connected to an AC power supply, and an output end of the current acquisition unit is connected to the current conversion unit;

[0010] The current acquisition unit is used to acquire the current signal corresponding to the AC fan;

[0011] The current conversion unit is used to convert the current signal corresponding to the AC fan into a voltage signal and send it to the amplification module.

[0012] In some embodiments, the current acquisition unit is a current transformer, the current conversion unit is a first resistor connected in parallel with the current transformer, and two ends of the first resistor are two output ends of the sampling module.

[0013] In some embodiments, the amplification module includes: an amplification unit and a bias unit,

[0014] The amplifying unit is used to amplify the first voltage signal to obtain an amplified voltage signal;

[0015] The bias unit is used to bias the amplified voltage signal through a bias voltage to obtain the second voltage signal within the preset voltage range.

[0016] In some embodiments, the amplification unit includes: a second resistor, a third resistor, an operational amplifier and a fourth resistor, and the sampling module includes two output terminals;

[0017] One end of the second resistor is connected to an output end of the sampling module, and the other end of the second resistor is connected to the first input end of the operational amplifier; one end of the third resistor is connected to the other output end of the sampling module, and the other end of the third resistor is connected to the second input end of the operational amplifier and one end of the fourth resistor, and the output end of the operational amplifier is connected to the input end of the controller and the other end of the fourth resistor;

[0018] The bias unit comprises a fifth resistor, one end of the fifth resistor is connected to a bias voltage source, and the other end of the fifth resistor is connected to the other end of the second resistor and the first input end of the operational amplifier.

[0019] In some embodiments, the circuit further comprises: a switch unit;

[0020] The input end of the switch unit is connected to the AC power supply of the AC fan, the output end of the switch unit is connected to the sampling module, and the control end of the switch unit is connected to the output end of the controller;

[0021] The controller is used to output a power-on control signal to the control end of the switch unit, so that the input end of the switch unit is connected to the output end of the switch unit to power on the AC fan.

[0022] In some embodiments, the controller is specifically used to determine that the AC fan is in a fault state when the difference between the actual power and the rated power of the AC fan is greater than or equal to a preset value, and to determine that the AC fan is in a normal working state when the difference between the actual power and the rated power of the AC fan is less than a preset value.

[0023] In some embodiments, the transformation ratio of the current transformer is 5A:2.5mA;

[0024] The first resistor is a 0.1% 25PPM high-precision low-temperature floating 100Ω resistor.

[0025] In some embodiments, the second resistor and the third resistor are 0.1% 25PPM high precision low temperature floating 100KΩ resistors; the fourth resistor is 0.1% 25PPM high precision low temperature floating 300KΩ resistor.

[0026] In some embodiments, the switch unit is a 5V control relay, the maximum voltage allowed by the relay is 250V, and the maximum operating current allowed by the relay is 5A.

[0027] The above-mentioned AC fan operation status monitoring circuit, since in the circuit, the sampling module can collect the first voltage signal corresponding to the AC fan, and send the collected first voltage signal to the amplification module, and after the amplification module performs advanced processing, the obtained second voltage signal is sent to the controller, so that the controller can calculate the actual power of the AC fan according to the second voltage signal corresponding to the AC fan, and judge the operation status of the AC fan accordingly, so that the circuit can realize the detection of the operation status of the AC fan and timely know the operation status of the AC fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are 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.

[0029] FIG1 is a schematic diagram of a circuit in which an AC fan is located in the prior art in one embodiment;

[0030] FIG2 is a schematic diagram of a circuit for monitoring the operation status of an AC fan in one embodiment;

[0031] FIG3 is a second schematic diagram of an AC fan operating status monitoring circuit in one embodiment;

[0032] Figure 4 The figure is a detailed schematic diagram of a part of the circuit in the AC fan operation status monitoring circuit in one embodiment. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0034] The ordinary fan circuit has only one switch. When the switch is closed, the fan starts, and when the switch is open, the fan stops. The controller can only control the fan to power on or off through the switch, but it is completely unable to understand the actual operating status of the fan. There is an urgent need for a way to detect the operating status of the fan.

[0035] For example, Figure 1 is a schematic diagram of a circuit in which an AC fan is located in the prior art. As shown in Figure 1, one end of an AC power source 11 is connected to one end of a fan 12, and a switch 13 is connected between the other end of the AC power source 11 and the fan 12. When the switch 13 is closed, the fan starts, and when the switch is opened, the fan stops. The controller can start or stop the fan by controlling the switch 13, but the actual operating status of the fan cannot be known.

[0036] In order to solve the above problems, an embodiment of the present application provides an AC fan operating status monitoring circuit, through which the AC fan operating status can be detected and the AC fan operating status can be known in time.

[0037] For example, Fig. 2 is a schematic diagram of a circuit for monitoring the operation status of an AC fan. As shown in Fig. 2, the circuit includes: a sampling module 21 connected in series with the AC fan 20, an amplifying module 22 connected to the sampling module 21, and a controller 23 connected to the amplifying module 22;

[0038] The sampling module 21 is used to collect the first voltage signal corresponding to the AC fan 20, and send the collected first voltage signal to the amplification module 22;

[0039] The amplification module 22 is used to amplify the first voltage signal to obtain a second voltage signal within a preset voltage range;

[0040] The controller 23 is used to calculate the actual power of the AC fan 20 based on the second voltage signal, and determine the operating state of the AC fan 20 based on the actual power.

[0041] In some embodiments, the amplification module comprises: an amplification unit and a bias unit.

[0042] The amplifying unit is used to amplify the first voltage signal to obtain an amplified voltage signal;

[0043] The bias unit is used to bias the amplified voltage signal through a bias voltage to obtain the second voltage signal within the preset voltage range.

[0044] In some embodiments, the preset voltage range may be greater than 0V and less than or equal to 3.3V, and the bias voltage may be 1.5V.

[0045] This AC fan operating status monitoring circuit is mainly composed of three parts: sampling module, amplification module and controller.

[0046] First, the sampling module is connected in series with the AC fan to collect the first voltage signal corresponding to the AC fan. Since the AC fan will produce a specific voltage change during operation, the sampling module can capture this voltage signal and send it to the amplification module.

[0047] Next, after receiving the first voltage signal from the sampling module, the amplification module amplifies it. This is because the collected original voltage signal may be relatively weak or not within the range suitable for the controller to process. After amplification, a second voltage signal within a preset voltage range (greater than 0V and less than or equal to 3.3V) is obtained. This preset voltage range is to ensure that the subsequent controller can effectively process the signal.

[0048] Finally, the controller receives the amplified second voltage signal. Based on this signal, the controller calculates the actual power of the AC fan, and may use specific algorithms and formulas to determine the power value using parameters such as voltage and current. Then, based on the calculated actual power, the controller can determine the operating status of the AC fan, such as normal operation, overload, underload and other different states, so as to monitor and manage the AC fan to ensure its safe and stable operation. In short, this circuit realizes effective monitoring of the operating status of the AC fan through steps such as sampling, amplification and calculation.

[0049] In some embodiments, the above-mentioned controller is specifically used to determine that the AC fan is in a fault state when the difference between the actual power and the rated power of the AC fan is greater than or equal to a preset value, and to determine that the AC fan is in a normal working state when the difference between the actual power and the rated power of the AC fan is less than a preset value.

[0050] That is to say, when the difference between the actual power and the rated power of the AC fan is greater than or equal to the preset value, it means that the working state of the AC fan is greatly different from the normal working state, and there may be a short circuit or damage. In this case, it can be determined that the AC fan is in a fault state. When the difference between the actual power and the rated power of the AC fan is less than the preset value, it means that the working state of the AC fan is similar to the normal working state. At this time, the AC fan is considered to be in a normal working state.

[0051] The above-mentioned AC fan operation status monitoring circuit, since in the circuit, the sampling module can collect the first voltage signal corresponding to the AC fan, and send the collected first voltage signal to the amplification module, and after the amplification module performs advanced processing, the obtained second voltage signal is sent to the controller, so that the controller can calculate the actual power of the AC fan according to the second voltage signal corresponding to the AC fan, and judge the operation status of the AC fan accordingly, so that the circuit can realize the detection of the operation status of the AC fan and timely know the operation status of the AC fan.

[0052] For example, based on FIG2 , FIG3 is a schematic diagram of a second circuit for monitoring the operation status of an AC fan. As shown in FIG3 , the circuit includes: a sampling module 21 connected in series with an AC fan 20, an amplifying module 22 connected to the sampling module 21, and a controller 23 connected to the amplifying module 22; wherein the AC fan 20 is also connected to the AC power supply 25 and the switch unit 24 in FIG3 .

[0053] In some embodiments, the sampling module 21 includes: a current acquisition unit 211 and a current conversion unit 212, wherein a first input end of the current acquisition unit 211 is connected to the AC fan 20, a second input end of the current acquisition unit 211 is connected to an AC power source 25 (may be connected to the AC power source 25 through a switch unit 24), and an output end of the current acquisition unit 211 is connected to the current conversion unit 212;

[0054] The current acquisition unit 211 is used to acquire the current signal corresponding to the AC fan 20;

[0055] The current conversion unit 212 is used to convert the current signal corresponding to the AC fan 20 into a voltage signal and send it to the amplification module 22 .

[0056] In some embodiments, the current acquisition unit 211 is a current transformer, the current conversion unit 212 is a first resistor connected in parallel with the current transformer, and two ends of the first resistor are two output ends of the sampling module.

[0057] In some embodiments, the transformation ratio of the current transformer is 5A:2.5mA; the first resistor is a 0.1% 25PPM high-precision low-temperature floating 100Ω resistor.

[0058] In some embodiments, based on FIG. 2 , as shown in FIG. 3 , the amplification module 22 (specifically, it may be an amplification unit in the amplification module 22 ) includes: a second resistor R5 , a third resistor R6 , an operational amplifier U1 , and a fourth resistor R4 , and the sampling module 21 includes two output terminals;

[0059] One end of the second resistor R5 is connected to an output end of the sampling module 21, and the other end of the second resistor is connected to the first input end of the operational amplifier U1; one end of the third resistor R6 is connected to the other output end of the sampling module 21, and the other end of the third resistor R6 is connected to the second input end of the operational amplifier U1 and one end of the fourth resistor R4, and the output end of the operational amplifier U1 is connected to the input end of the controller 23 and the other end of the fourth resistor R4.

[0060] In some embodiments, in FIG. 3 , the second resistor and the third resistor are 0.1% 25PPM high-precision low-temperature floating 100KΩ resistors; the fourth resistor is 0.1% 25PPM high-precision low-temperature floating 300KΩ resistor.

[0061] The amplification module 22 may further include a bias unit for biasing the amplified voltage signal by a bias voltage to obtain a second voltage signal within a preset voltage range. The bias unit includes a fifth resistor, one end of the fifth resistor is connected to the bias voltage source, and the other end of the fifth resistor is connected to the other end of the second resistor and the first input end of the operational amplifier.

[0062] In some embodiments, as shown in FIG3 , the circuit further includes: a switch unit 24;

[0063] The input end of the switch unit 24 is connected to the AC power supply of the AC fan 20, the output end of the switch unit 24 is connected to the sampling module 21, and the control end of the switch unit 24 is connected to the output end of the controller 23;

[0064] The controller 23 is used to output a power-on control signal to the control end of the switch unit 24 so that the input end of the switch unit 24 is connected to the output end of the switch unit 24 to power on the AC fan 20 .

[0065] In some embodiments, the switch unit is a 5V control relay, the maximum voltage allowed by the relay is 250V, and the maximum operating current allowed by the relay is 5A.

[0066] The circuit shown in FIG3 has the following beneficial effects:

[0067] First, the circuit uses a sampling module that includes a current acquisition unit and a current conversion unit. The current acquisition unit collects the current signal of the AC fan, and the current conversion unit converts the current signal into a voltage signal for subsequent processing. This design can effectively monitor the operating status of the AC fan, because the current is a key parameter reflecting the working status of the fan. In addition, the current acquisition unit uses a current transformer, which has good electrical isolation characteristics and can improve the safety and stability of the circuit.

[0068] Secondly, high precision helps to ensure the accuracy of the signal conversion and amplification process in the circuit, making the monitoring data more reliable; the low temperature drift characteristic ensures the relative stability of the resistance value under different temperature environments, thereby ensuring the stability of the circuit performance and reducing the impact of temperature changes on the measurement results.

[0069] Furthermore, the amplification module uses an operational amplifier combined with a specific resistor connection method to appropriately amplify the converted voltage signal to meet the controller's requirements for input signal amplitude, thereby improving the controller's accuracy in monitoring the fan's operating status.

[0070] Finally, the switch unit in the circuit is controlled by the controller, which can easily realize the power-on control of the AC fan. The relay can switch between different voltage levels (5V controls 250V), and its maximum operating current is 5A, which can meet the power supply requirements of the AC fan. This design improves the controllability and adaptability of the circuit.

[0071] For example, based on FIG. 3 , Figure 4 As shown in Figure 1, a detailed schematic diagram of part of the AC fan operating status monitoring circuit is shown. Figure 4 As shown, Figure 4 The specific connection relationship among the switch unit 24, the AC power supply 25, the current acquisition unit 211, the first resistor R1 (corresponding to the current conversion unit 212 in FIG. 3 ), the second resistor R5, the third resistor R6, the operational amplifier U1 and the fourth resistor R4 is shown in FIG. It can be seen that some other components can also be included in the AC fan operation status monitoring circuit. Figure 4 As shown in the figure, transistor Q1, resistors R3, R9, R10, R11 and other resistors, and capacitors C1, C2, C3, C4, C6, C7, C9, C10 and other capacitors.

[0072] in, Figure 4The GND shown in the figure indicates the ground terminal, AD_VCC may indicate the power supply voltage provided by the circuit containing the mixed analog and digital parts; 1V5_VCC indicates a 1.5 volt power supply voltage, which is the bias voltage source used to provide the above bias voltage. Figure 4 R3 in the figure is the fifth resistor in the bias unit; ADC_FS indicates the signal input to the ADC (Analog-to-Digital Converter) port of the controller; 220V_L indicates the live wire of 220V, 220V_N indicates the neutral wire of 220V; 5V_VCC indicates the power supply voltage of 5V; terminal DO is connected to the controller. 10K marked on the resistor means 10 kilo-ohms, 2K means 2 kilo-ohms, 300K means 300 kilo-ohms, 0.1% 25PPM (Parts PerMillion) means the resistor has an accuracy level of 0.1% and a temperature coefficient (TC value) of 25PPM. For the capacitor, the 100nF / 50V mark means that the capacitance is 100 nanofarads, and the withstand voltage is 50V; 10nF / 50V means that the capacitance is 10 nanofarads, and the withstand voltage is 50V; 220pF / 50V means that the capacitance is 220 picofarads, and the withstand voltage is 50V; 100pF / 50V means that the capacitance is 100 picofarads, and the withstand voltage is 50V. Figure 4 The numbers 1, 2, 3, 4, 5, etc. marked on the device pins represent different pins.

[0073] In the embodiment of the present application, an AC fan operating status monitoring circuit is proposed to address the problem that ordinary fan circuits can only simply control the power on or off of the fan but cannot understand the operating status. In terms of circuit design, the sampling module in the circuit shown in Figure 3 can collect current signals and convert them into voltage signals for monitoring the operating status of the fan. The current acquisition unit uses a current transformer to provide electrical isolation, improve safety and stability; the high-precision low-temperature drift resistor in the sampling and amplification module ensures the accuracy and stability of signal conversion and amplification, and reduces the impact of temperature on the measurement results; the operational amplifier of the amplification module and the specific resistor connection method can meet the controller's requirements for signal amplitude and improve monitoring accuracy; the switch unit is controlled by the controller, and the relay can switch at different voltage levels and meet the fan power supply requirements, improving controllability and adaptability. Figure 4 further shows the detailed connection relationship of some circuits, providing a clearer circuit structure.

[0074] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above 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.

[0075] 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 understood as limiting the scope of the present 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 present application shall be subject to the attached claims.

Claims

1. An AC fan operating status monitoring circuit, characterized in that: The circuit comprises: a sampling module connected in series with the AC fan, an amplification module connected with the sampling module, and a controller connected with the amplification module; The sampling module is used to collect the first voltage signal corresponding to the AC fan and send the collected first voltage signal to the amplification module; The amplification module is used to amplify the first voltage signal to obtain a second voltage signal within a preset voltage range; The controller is used to calculate the actual power of the AC fan based on the second voltage signal, and determine the operating state of the AC fan based on the actual power.

2. The circuit according to claim 1, characterized in that The sampling module comprises: a current acquisition unit and a current conversion unit, wherein a first input end of the current acquisition unit is connected to the AC fan, a second input end of the current acquisition unit is connected to an AC power supply, and an output end of the current acquisition unit is connected to the current conversion unit; The current acquisition unit is used to acquire the current signal corresponding to the AC fan; The current conversion unit is used to convert the current signal corresponding to the AC fan into a voltage signal and send it to the amplification module.

3. The circuit according to claim 2, characterized in that The current acquisition unit is a current transformer, the current conversion unit is a first resistor connected in parallel with the current transformer, and two ends of the first resistor are two output ends of the sampling module.

4. The circuit according to claim 1, characterized in that The amplification module includes: an amplification unit and a bias unit. The amplifying unit is used to amplify the first voltage signal to obtain an amplified voltage signal; The bias unit is used to bias the amplified voltage signal through a bias voltage to obtain the second voltage signal within the preset voltage range.

5. The circuit according to claim 4, characterized in that The amplification unit includes: a second resistor, a third resistor, an operational amplifier and a fourth resistor, and the sampling module includes two output terminals; One end of the second resistor is connected to an output end of the sampling module, and the other end of the second resistor is connected to the first input end of the operational amplifier; one end of the third resistor is connected to the other output end of the sampling module, and the other end of the third resistor is connected to the second input end of the operational amplifier and one end of the fourth resistor, and the output end of the operational amplifier is connected to the input end of the controller and the other end of the fourth resistor; The bias unit comprises a fifth resistor, one end of the fifth resistor is connected to a bias voltage source, and the other end of the fifth resistor is connected to the other end of the second resistor and the first input end of the operational amplifier.

6. The circuit according to claim 1, characterized in that The circuit further comprises: a switch unit; The input end of the switch unit is connected to the AC power supply of the AC fan, the output end of the switch unit is connected to the sampling module, and the control end of the switch unit is connected to the output end of the controller; The controller is used to output a power-on control signal to the control end of the switch unit, so that the input end of the switch unit is connected to the output end of the switch unit to power on the AC fan.

7. The circuit according to claim 1, characterized in that The controller is specifically used to determine that the AC fan is in a fault state when the difference between the actual power and the rated power of the AC fan is greater than or equal to a preset value, and to determine that the AC fan is in a normal working state when the difference between the actual power and the rated power of the AC fan is less than a preset value.

8. The circuit according to claim 3, characterized in that The transformation ratio of the current transformer is 5A:2.5mA; The first resistor is a 0.1% 25PPM high-precision low-temperature floating 100Ω resistor.

9. The circuit according to claim 5, characterized in that The second resistor and the third resistor are 0.1% 25PPM high-precision low-temperature floating 100KΩ resistors; the fourth resistor is 0.1% 25PPM high-precision low-temperature floating 300KΩ resistor.

10. The circuit according to claim 6, characterized in that The switch unit is a 5V control relay, the maximum voltage allowed by the relay is 250V, and the maximum operating current allowed by the relay is 5A.

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