Multi-fan current detection circuit
By designing a multi-fan current detection circuit suitable for both the DC bias voltage generation unit and the fan current sampling unit, the problem that existing technologies cannot simultaneously detect DC and AC fan currents is solved, achieving accurate detection of both types of fan currents and simplifying the circuit.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XIAMEN LEELEN HIGH VOLTAGE ELECTRIC CO LTD
- Filing Date
- 2025-05-23
- Publication Date
- 2026-05-26
AI Technical Summary
Existing high-voltage equipment current detection circuits cannot be applied to both DC and AC fans simultaneously, and their structure is complex and costly.
A multi-fan current detection circuit was designed, which includes a DC bias voltage generation unit and a fan current sampling unit. The DC bias voltage generation unit provides a DC bias voltage to the AC fan, so that the voltage signal output by the fan current sampling unit is within the input range of the microcontroller's ADC. The circuit is then converted into current using resistors and diodes, simplifying the circuit structure.
It enables accurate detection of the operating current of DC and AC fans, simplifies the circuit structure, and reduces costs.
Smart Images
Figure CN224286996U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of high voltage equipment, and in particular to a multi-fan current detection circuit. Background Technology
[0002] In existing high-voltage equipment (such as high-voltage control cabinets), fans play a crucial role. They remove the heat generated during the operation of high-voltage equipment through forced ventilation, ensuring effective heat dissipation and maintaining a suitable operating temperature. This prevents various accidents caused by excessive temperature, such as insulation aging, electronic component burnout, and flashover, thus improving the safety of high-voltage equipment operation. Currently, current detection circuits are generally used to detect the fan's operating current to determine if the fan is faulty. A common current detection circuit for fans uses a current transformer to obtain the induced signal generated by the fan's operating current, then amplifies the signal through a differential operational amplifier circuit before outputting it to a microcontroller. This type of current detection circuit is relatively complex and expensive, and it is only applicable to DC fans, thus having limitations.
[0003] In view of the above problems, it is necessary to study a multi-fan current detection circuit that can be used to detect the operating current of DC fans and AC fans, and has a simple structure. Utility Model Content
[0004] The purpose of this invention is to provide a multi-fan current detection circuit, which can be used to detect the operating current of DC fans and AC fans, and has a simple structure.
[0005] To achieve the above objectives, the solution of this utility model is:
[0006] A multi-fan current detection circuit includes a DC bias voltage generating unit and at least one fan current sampling unit. Each fan current sampling unit includes a first resistor, a second resistor, a third resistor, a first diode, and a second diode. The first end of the first resistor and the first end of the second resistor are connected to the first fan connection terminal of the fan current sampling unit. The second end of the first resistor is connected to the second fan connection terminal of the fan current sampling unit. The second end of the second resistor is connected to the first end of the third resistor, the positive terminal of the first diode, and the negative terminal of the second diode. The negative terminal of the first diode is connected to a control power supply, and the positive terminal of the second diode is grounded. The second end of the third resistor is connected to the sampling output terminal of the fan current sampling unit. The output terminal of the DC bias voltage generating unit is connected to the second fan connection terminal of each fan current sampling unit.
[0007] Each wind turbine current sampling unit also includes a first capacitor, with the first end of the first capacitor connected to the sampling output terminal of the wind turbine current sampling unit and the second end of the first capacitor grounded.
[0008] The DC bias voltage generating unit includes a reference voltage generating unit, a first operational amplifier, a fourth resistor, and a fifth resistor. The output terminal of the reference voltage generating unit is connected to the non-inverting input terminal of the first operational amplifier, the inverting input terminal of the first operational amplifier is connected to the first terminal of the fourth resistor, the output terminal of the first operational amplifier is connected to the first terminal of the fifth resistor, and the second terminals of the fourth and fifth resistors are connected to the output terminal of the reference voltage generating unit.
[0009] The reference voltage generating unit includes a sixth resistor and a seventh resistor. The first end of the sixth resistor is connected to the control power supply, the second end of the sixth resistor and the first end of the seventh resistor are connected to the output terminal of the reference voltage generating unit, and the second end of the seventh resistor is grounded.
[0010] With the above scheme, in use, the multi-fan current detection circuit of this utility model connects the first fan connection terminal and the second fan connection terminal of each fan current sampling unit to the two ends of a fan, respectively. The sampling output terminal of each fan current sampling unit is connected to an ADC sampling port of a microcontroller. The fan current sampling unit can convert the fan's operating current into a voltage signal and output it to the microcontroller, so that the microcontroller can detect the fan's operating current through this utility model. In addition, the DC bias voltage generating unit of this utility model can provide a DC bias voltage to the fan. Even if the fan is an AC fan, the DC bias voltage can ensure that the voltage signal output by the fan current sampling unit is completely within the input range of the microcontroller's ADC, ensuring that the microcontroller can obtain the complete waveform of the voltage signal output by the fan current sampling unit. This allows the microcontroller to accurately detect the fan's operating current. Thus, this utility model is applicable to detecting the operating current of both DC and AC fans, and the DC bias voltage generating unit and the fan current sampling unit have few components and a simple structure. Attached Figure Description
[0011] Figure 1 This is the circuit schematic diagram of this utility model.
[0012] Label Explanation:
[0013] DC bias voltage generation unit 1, reference voltage generation unit 11, sixth resistor R6, seventh resistor R7, first operational amplifier U1, fourth resistor R4, fifth resistor R5.
[0014] The fan current sampling unit 2 consists of a first resistor R1, a second resistor R2, a third resistor R3, a first diode D1, a second diode D2, and a first capacitor C1.
[0015] Control power supply VCC. Detailed Implementation
[0016] To further explain the technical solution of this utility model, the following detailed description is provided through specific embodiments.
[0017] like Figure 1 As shown, this utility model discloses a multi-fan current detection circuit, which includes a DC bias voltage generating unit 1 and at least one fan current sampling unit 2. Each fan current sampling unit 2 includes a first resistor R1, a second resistor R2, a third resistor R3, a first diode D1, and a second diode D2. The first end of the first resistor R1 and the first end of the second resistor R2 are connected to the first fan connection terminal of the fan current sampling unit 2. The second end of the first resistor R1 is connected to the second fan connection terminal of the fan current sampling unit 2. The second end of the second resistor R2 is connected to the first end of the third resistor R3, the positive terminal of the first diode D1, and the negative terminal of the second diode D2. The first diode D1's cathode is connected to the control power supply VCC, the second diode D2's anode is grounded, and the second terminal of the third resistor R3 is connected to the sampling output terminal of the fan current sampling unit 2. The first resistor R1 converts current to voltage, the second and third resistors R2 limit current, and the first and second diodes D1 and D2 clamp voltage to protect the downstream microcontroller. The output terminal of the DC bias voltage generating unit 1 is connected to the second fan connection terminal of each fan current sampling unit 2, providing a DC bias voltage to the second fan connection terminal of the fan current sampling unit 2.
[0018] In use, the multi-fan current detection circuit of this invention connects the first and second fan connection terminals of each fan current sampling unit 2 to the two ends of a fan, respectively. The sampling output terminal of each fan current sampling unit 2 is connected to an ADC sampling port of a microcontroller. The fan current sampling unit 2 converts the fan's operating current into a voltage signal and outputs it to the microcontroller, enabling the microcontroller to detect the fan's operating current. Furthermore, the DC bias voltage generating unit 1 provides a DC bias voltage to the fan, thus ensuring that even if the fan is AC... The DC bias voltage of the fan ensures that the voltage signal output by the fan current sampling unit 2 is completely within the input range of the microcontroller's ADC, thus ensuring that the microcontroller can acquire the complete waveform of the voltage signal output by the fan current sampling unit 2. This allows the microcontroller to accurately detect the fan's operating current (the microcontroller needs to deduct the DC bias voltage provided by the DC bias voltage generation unit 1 when calculating the fan's operating current). Therefore, this invention is applicable to detecting the operating current of both DC and AC fans. Moreover, the DC bias voltage generation unit 1 and the fan current sampling unit 2 have fewer components and a simpler structure.
[0019] In an embodiment of this utility model, each fan current sampling unit 2 further includes a first capacitor C1. The first end of the first capacitor C1 is connected to the sampling output terminal of the fan current sampling unit 2, and the second end of the first capacitor C1 is grounded. The first capacitor C1 is used to stabilize the sampling output voltage of the fan current sampling unit 2.
[0020] In an embodiment of this utility model, the DC bias voltage generating unit 1 may include a reference voltage generating unit 11, a first operational amplifier U1, a fourth resistor R4, and a fifth resistor R5. The output terminal of the reference voltage generating unit 11 is connected to the non-inverting input terminal of the first operational amplifier U1, the inverting input terminal of the first operational amplifier U1 is connected to the first terminal of the fourth resistor R4, the output terminal of the first operational amplifier U1 is connected to the first terminal of the fifth resistor R5, and the second terminals of the fourth resistor R4 and the fifth resistor R5 are connected to the output terminal of the reference voltage generating unit 11. The reference voltage generating unit 11 may include a sixth resistor R4. Resistor R6 and resistor R7 are connected together. The first end of resistor R6 is connected to the control power supply VCC, and the second end of resistor R6 and the first end of resistor R7 are connected to the output terminal of reference voltage generation unit 11. The second end of resistor R7 is grounded. Resistor R6 and resistor R7 form a voltage divider circuit to output a reference voltage to the non-inverting input terminal of the first operational amplifier U1. The first operational amplifier U1, resistor R4, and resistor R5 form a voltage follower. The first operational amplifier U1 has an isolation function to ensure the stability of the reference voltage output by reference voltage generation unit 11.
[0021] The above embodiments and figures are not intended to limit the product form and style of this utility model. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of this utility model.
Claims
1. A multi-fan current detection circuit, characterized by: Includes a DC bias voltage generation unit and at least one fan current sampling unit; Each fan current sampling unit includes a first resistor, a second resistor, a third resistor, a first diode, and a second diode. The first end of the first resistor and the first end of the second resistor are connected to the first fan connection terminal of the fan current sampling unit. The second end of the first resistor is connected to the second fan connection terminal of the fan current sampling unit. The second end of the second resistor is connected to the first end of the third resistor, the positive terminal of the first diode, and the negative terminal of the second diode. The negative terminal of the first diode is connected to the control power supply, the positive terminal of the second diode is grounded, and the second end of the third resistor is connected to the sampling output terminal of the fan current sampling unit. The output terminal of the DC bias voltage generating unit is connected to the second fan connection terminal of each fan current sampling unit.
2. The multi-fan current detection circuit as described in claim 1, characterized in that: Each wind turbine current sampling unit also includes a first capacitor, with the first end of the first capacitor connected to the sampling output terminal of the wind turbine current sampling unit and the second end of the first capacitor grounded.
3. The multi-fan current detection circuit as described in claim 1, characterized in that: The DC bias voltage generating unit includes a reference voltage generating unit, a first operational amplifier, a fourth resistor, and a fifth resistor. The output terminal of the reference voltage generating unit is connected to the non-inverting input terminal of the first operational amplifier, the inverting input terminal of the first operational amplifier is connected to the first terminal of the fourth resistor, the output terminal of the first operational amplifier is connected to the first terminal of the fifth resistor, and the second terminals of the fourth and fifth resistors are connected to the output terminal of the reference voltage generating unit.
4. The multi-fan current detection circuit as described in claim 3, characterized in that: The reference voltage generating unit includes a sixth resistor and a seventh resistor. The first end of the sixth resistor is connected to the control power supply, the second end of the sixth resistor and the first end of the seventh resistor are connected to the output terminal of the reference voltage generating unit, and the second end of the seventh resistor is grounded.