Double-air-gap high-precision high-range current sensor

Abstract

The invention relates to the technical field of current sensors, in particular to a double-air-gap high-precision high-range current sensor which comprises two Hall chips and an MCU controller, the two Hall chips are used for outputting magnetic field signals into two paths of electric signals, the MCU controller is used for collecting and processing output signals of the Hall chips, and the MCU controller is used for controlling the Hall chips to output the output signals. Averaging the output signals of the two paths of Hall chips; and by adopting the design of averaging output of the two Hall chips, the accuracy and the stability of measurement can be improved. By averaging the output signals of the two Hall chips, measurement errors caused by factors such as errors and temperature drift of the chips can be reduced; the double-air-gap high-precision high-range current sensor provided by the invention can maintain good performance when being influenced by external temperature and humidity, and solves the technical problem that the accuracy and stability of a double-air-gap current sensor in the prior art become poor due to the fact that the double-air-gap current sensor is easily influenced by external temperature and humidity.

Description

Technical Field

[0001] The invention relates to the technical field of current sensors, and in particular to a double-air-gap high-precision and high-range current sensor. Background Art

[0002] The double air gap current sensor usually consists of a magnetic core, windings, an air gap and a housing. Among them, the magnetic core is the core component of the sensor, usually made of high magnetic permeability materials such as ferrite or Permalloy. The windings include primary windings and secondary windings, which are used to input and output current signals respectively. The air gap is the gap in the magnetic core, which is used to adjust the magnetic resistance of the magnetic circuit, thereby affecting the performance of the sensor. The housing is used to protect the components inside the sensor from interference from the external environment. In the double air gap current sensor, the magnetic core is usually designed as two opposite and spaced U-shaped structures, forming two air gaps between them. This structure makes the magnetic circuit more complete and the magnetic flux more stable, thereby improving the measurement accuracy and stability of the sensor.

[0003] The double air-gap current sensor has the advantages of high precision, wide frequency response, small size, non-contact measurement and current control capabilities. The magnetic circuit of the double air-gap current transformer is relatively short, so its frequency response is high, which can be applied to current measurement needs of different frequencies. Compared with other types of current transformers, the double air-gap current transformer is smaller in size, which makes it more convenient during installation and maintenance. The double air-gap current sensor usually adopts a non-contact measurement method, which avoids the electrical connection problems that may occur in traditional current transformers during measurement, and improves the safety and reliability of measurement. Some double air-gap Hall current sensors are designed with current control function, and the connection wires that need to control the current can be stably fixed through specific structures (such as plug-in boards, struts, etc.) to ensure the accuracy of current control.

[0004] However, in actual use, the double air-gap current sensor still has certain shortcomings: although the double air-gap current sensor has taken into account the factors of reducing external interference in its design, it may still be affected by environmental factors such as temperature and humidity, resulting in a certain impact on the accuracy and stability of the measurement results. Summary of the invention

[0005] The invention provides a double air gap high-precision high-range current sensor to solve the technical problem in the prior art that the double air gap current sensor is easily affected by external temperature and humidity, resulting in poor accuracy and stability.

[0006] To solve the above problems, the double air gap high-precision high-range current sensor provided by the present invention adopts the following technical solutions:

[0007] A double air gap high-precision high-range current sensor includes two Hall chips, which are used to output magnetic field signals as two electrical signals, and an MCU controller, which is used to collect and process the output signals of the Hall chips and average the output signals of the two Hall chips to improve measurement accuracy and stability.

[0008] Furthermore, capacitors and resistors are correspondingly arranged on the output circuits of the two Hall chips. The capacitors are used to filter out high-frequency noise in the signals, and the resistors are used to divide the voltage and limit the current in the circuit to adjust the signal amplitude.

[0009] Furthermore, the capacitance corresponding to the two Hall chips is 4.7nF. The 4.7nF capacitance can effectively filter out common high-frequency interference without excessively affecting the signal response time.

[0010] Furthermore, the resistances corresponding to the two Hall chips are both 1KΩ. The resistance value of 1KΩ can be well matched with other components in the circuit (such as the output impedance of the Hall chip, the input impedance of the MCU controller, etc.), ensuring that the signal can be effectively transmitted and processed.

[0011] Furthermore, the MCU controller has an ADC analog-to-digital converter inside, which is used to convert the collected analog voltage signal into a digital signal.

[0012] Furthermore, the MCU controller has two reference voltage inputs for providing a reference voltage for an ADC analog-to-digital converter.

[0013] Furthermore, the MCU controller collects voltage signals through the I NPUT pin and outputs signals through the OUTPUT pin.

[0014] The beneficial effects of the dual air gap high-precision high-range current sensor provided by the present invention are: the design of taking the average of the dual-channel Hall chip output can improve the accuracy and stability of the measurement. By averaging the output signals of the two Hall chips, the measurement error caused by factors such as chip errors and temperature drift can be reduced; the circuit design integrates multiple key components, such as Hall chips, capacitors, resistors and MCU controllers, so that the entire current sensor has a high degree of integration, reduces the possibility of external interference, and is easy to install and use. The filtering effect of the capacitor and the voltage dividing and current limiting effect of the resistor make the output signal more stable and can maintain good performance under different working environments; the addition of the MCU controller enables the current sensor to have intelligent control capabilities, and can perform flexible control operations based on the collected data, thereby improving the degree of automation of the system;

[0015] In summary, through the above-mentioned settings, the dual air gap high-precision and high-range current sensor provided by the present invention can maintain good performance even when affected by external temperature and humidity, thereby solving the technical problem in the prior art that the dual air gap current sensor is easily affected by external temperature and humidity, resulting in poor accuracy and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0017] Figure 1 The schematic diagram of the circuit of the double air gap high-precision high-range current sensor provided by the present invention.

[0018] Description of reference numerals:

[0019] 1. Hall chip; 2. MCU controller; 3. Capacitor; 4. Resistor; 5. ADC analog-to-digital converter; 6. Reference voltage; 7. INPUT pin; 8. OUTPUT pin. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0021] It should be noted that the main idea of ​​the present invention is that the design of taking the average value of the output of the two-way Hall chip 1 can improve the accuracy and stability of the measurement. By averaging the output signals of the two-way Hall chip 1, the measurement error caused by factors such as the chip error and temperature drift can be reduced; multiple key components such as the Hall chip 1, capacitor 3, resistor 4 and MCU controller 2 are integrated in the circuit design, so that the entire current sensor has a high degree of integration, reduces the possibility of external interference, and is easy to install and use. The filtering effect of the capacitor 3 and the voltage-limiting current effect of the resistor 4 make the output signal more stable and can maintain good performance under different working environments; the addition of the MCU controller enables the current sensor to have the ability of intelligent control, and can perform flexible control operations according to the collected data, thereby improving the automation of the system; in order to solve the technical problem that the double air gap current sensor in the prior art is easily affected by the external temperature and humidity, resulting in poor accuracy and stability.

[0022] After introducing the basic principle of the present invention, various non-limiting embodiments of the present invention are described in detail below. The number of any element in the drawings is for illustration and not for limitation, and any naming is only for distinction and does not have any limiting meaning.

[0023] The principle and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

[0024] Embodiment 1 of the double air gap high-precision high-range current sensor provided by the present invention:

[0025] like Figure 1 As shown, the dual air gap high-precision high-range current sensor includes two Hall chips 1, which are used to output magnetic field signals as two electrical signals, and also includes an MCU controller 2, which is used to collect and process the output signals of the Hall chips 1 and average the output signals of the two Hall chips 1 to improve measurement accuracy and stability.

[0026] Among them, the output circuits of the two Hall chips 1 are respectively provided with capacitors 3 and resistors 4. The capacitor 3 is used to filter out high-frequency noise in the signal, and the resistor 4 is used to divide the voltage and limit the current in the circuit to adjust the signal amplitude.

[0027] Specifically, the capacitors 3 corresponding to the two Hall chips 1 are both 4.7nF. The 4.7nF capacitor 3 can effectively filter out common high-frequency interference without excessively affecting the response time of the signal. The resistors 4 corresponding to the two Hall chips 1 are both 1KΩ. The resistance value of 1KΩ can be well matched with other components in the circuit (such as the output impedance of the Hall chip 1, the input impedance of the MCU controller 2, etc.), ensuring that the signal can be effectively transmitted and processed.

[0028] If you need to further filter out high-frequency noise, you can increase the capacitance appropriately, but be aware that too large a capacitance 3 will slow down the signal response and affect the real-time performance of the measurement. For example, you can consider increasing the capacitance to 10nF, but it should not be too large.

[0029] If you need to speed up the signal response, you can reduce the capacitance appropriately, but make sure that high-frequency interference can be effectively filtered out. For example, you can consider reducing the capacitance to 2.2nF.

[0030] If the output voltage needs to be further reduced, the resistance value can be appropriately increased, but it should be noted that an excessively large resistance 4 will cause excessive signal attenuation and affect the measurement accuracy. For example, you can consider increasing the resistance 4 to 2KΩ.

[0031] If you need to increase the current driving capability of the signal, you can reduce the resistance value appropriately, but make sure that the current is not too large and damages the component. For example, you can consider reducing the resistance to 500Ω.

[0032] When adjusting the values ​​of capacitor 3 and resistor 4, it is necessary to comprehensively consider factors such as filtering effect, signal response speed, voltage division effect, current limiting effect, and matching of circuit components, and determine the best parameter values ​​through actual testing and optimization.

[0033] refer to Figure 1 The MCU controller 2 has an ADC analog-to-digital converter 5 inside, which is used to convert the collected analog voltage signal into a digital signal. The MCU controller 2 has two reference voltage 6 inputs, which are used to provide a reference voltage for the ADC analog-to-digital converter 5. The two reference voltages 6 are +Uref (positive reference voltage) and -Uref (negative reference voltage).

[0034] Finally, the MCU controller 2 collects the voltage signal through the I NPUT pin 7 and outputs the signal through the OUTPUT pin 8.

[0035] The working principle of the double air gap high-precision high-range current sensor provided by the present invention is: when the current (I c) passes through the Current Sensor (current sensor), according to Ampere's law, a magnetic field will be generated around the sensor. The strength of this magnetic field is proportional to the magnitude of the current passing through; the dual-channel Hall chip 1 (Ha ll 1 and Hall ll 2) detects the change in the magnetic field and converts the magnetic field signal into an electrical signal (U_out 1 and U_out 2); the capacitor 3 filters the electrical signal output by the Hall chip 1 to remove high-frequency noise and make the signal more stable. The resistor 4 performs voltage division or current limiting processing on the filtered signal to adjust the signal amplitude; the MCU controller 2 collects the processed Hall chip 1 output signal (U_out), performs analog-to-digital conversion (ADC), and processes and analyzes the collected data. Finally, the MCU controller 2 can perform corresponding control operations based on the processed data;

[0036] The design of taking the average value of the output of the dual-channel Hall chip 1 effectively reduces the measurement error and improves the measurement accuracy; the filtering effect of capacitor 3 and the voltage division and current limiting effect of resistor 4 make the output signal more stable and can maintain good performance under different working environments; the circuit integrates multiple key components, reduces external interference, is easy to install and use, and is suitable for various application scenarios; the addition of MCU controller 2 enables the current sensor to have intelligent control capabilities, and can perform flexible control operations based on the collected data, thereby improving the degree of automation of the system.

[0037] Embodiment 2 of the double air gap high-precision high-range current sensor provided by the present invention:

[0038] The main difference between it and Example 1 is:

[0039] In Example 1, the capacitance corresponding to the two Hall chips is 4.7 nF. The 4.7 nF capacitance can effectively filter out common high-frequency interference without excessively affecting the signal response time.

[0040] In this embodiment, the value of the capacitor can be adjusted according to actual needs and can also be 2.2nF.

[0041] Embodiment 3 of the double air gap high-precision high-range current sensor provided by the present invention:

[0042] The main difference between it and Example 1 is:

[0043] In Example 1, the resistances corresponding to the two Hall chips are both 1KΩ. The resistance value of 1KΩ can be well matched with other components in the circuit (such as the output impedance of the Hall chip, the input impedance of the MCU controller, etc.), ensuring that the signal can be effectively transmitted and processed.

[0044] In this embodiment, the value of the resistor can be adjusted according to actual needs and can also be 500Ω.

[0045] According to the above description of this specification, those skilled in the art may also understand that the terms used below, such as "up", "down", "front", "back", "left", "right", "width", "horizontal", "top", "bottom", "inside", "outside" and the like, which indicate orientation or positional relationships, are based on the orientation or positional relationships shown in the drawings of this specification, and are only for the purpose of facilitating the explanation of the scheme of the present invention and simplifying the description, rather than explicitly or implicitly indicating that the devices or elements involved must have the specific orientation, be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms cannot be understood or interpreted as limitations on the scheme of the present invention.

[0046] In addition, in the description of this specification, “plurality” means at least two, for example, two, three or more, etc., unless otherwise clearly and specifically defined.

Claims

1. A double air gap high precision high range current sensor, characterized in that: The system includes two Hall chips, which are used to output magnetic field signals as two electrical signals, and an MCU controller, which is used to collect and process the output signals of the Hall chips and average the output signals of the two Hall chips to improve measurement accuracy and stability.

2. The double air gap high-precision high-range current sensor according to claim 1, characterized in that: The output circuits of the two Hall chips are equipped with capacitors and resistors. The capacitors are used to filter out high-frequency noise in the signal, and the resistors are used to divide the voltage and limit the current in the circuit to adjust the signal amplitude.

3. The double air gap high precision high range current sensor according to claim 2, characterized in that: The capacitance corresponding to the two Hall chips is 4.7nF.

4. The double air gap high precision high range current sensor according to claim 2, characterized in that: The resistances corresponding to the two Hall chips are both 1KΩ.

5. The double air gap high-precision high-range current sensor according to any one of claims 1 to 5, characterized in that: The MCU controller has an ADC analog-to-digital converter inside, which is used to convert the collected analog voltage signal into a digital signal.

6. The double air gap high precision high range current sensor according to claim 5, characterized in that: The MCU controller has two reference voltage inputs for providing reference voltages for the ADC analog-to-digital converter.

7. The double air gap high precision high range current sensor according to claim 5, characterized in that: The MCU controller collects voltage signals through the I NPUT pin and outputs signals through the OUTPUT pin.

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