A double-hall current sensor for improving product output precision

Abstract

The utility model provides a kind of double hall current sensor of improving product output precision, comprising: magnetic core coil, two hall sensors and operational amplifier, wherein: the magnetic core material of magnetic core coil is silicon steel, and coil is pure copper enameled wire;Air gap is set up in the symmetrical position of the two sides of magnetic core, and two hall sensors are respectively horizontally oppositely installed in air gap, for detecting magnetic field intensity.The utility model, by setting air gap in the symmetrical position of the two sides of magnetic core and horizontally oppositely placing double hall sensor, can synchronously detect the magnetic field intensity of the two sides of magnetic core, utilize the superposition or difference processing of double hall signal, offset the unilateral magnetic field intensity fluctuation caused by the position deviation of primary side current, so that sensor output precision is not influenced by primary side current position variation;The amplification processing of operational amplifier to double hall signal can enhance signal stability, improve detection sensitivity.

Description

Technical Field

[0001] This utility model relates to the field of current sensor technology, specifically to a dual Hall current sensor that improves the output accuracy of a product. Background Technology

[0002] In industrial settings, long-distance transmission of sensor signals is often required, making current signals the preferred choice due to their strong anti-interference capabilities. However, traditional single-Hall current sensors have significant drawbacks when measuring high currents (above kiloamperes): their accuracy is highest only when the primary current is located at the center of the sensor. Even slight deviations in the current position (such as installation errors or wire vibrations) can cause a significant drop in output accuracy due to changes in the magnetic field strength detected by the single-sided Hall sensor. This makes them unsuitable for applications requiring high precision and stability, such as industrial automation and power system monitoring.

[0003] Single Hall sensors detect the magnetic field in the air gap of the magnetic core at a single point, which cannot compensate for the uneven magnetic field distribution caused by the current position offset. They are also susceptible to interference from magnetic core nonlinearity and environmental noise (such as V-level noise voltage in industrial sites), resulting in large measurement errors.

[0004] Existing open-loop current sensors compensate for the primary magnetic flux by using secondary-side compensation current. However, the compensation mechanism of a single Hall effect sensor relies on a single-point signal and is sensitive to current position. Therefore, structural and circuit optimizations are needed to improve the sensor's robustness to current position changes and enhance its anti-interference capabilities.

[0005] To address this, a dual Hall effect current sensor is proposed to improve the output accuracy of the product. Utility Model Content

[0006] The present invention aims to solve the problems mentioned in the background art by providing a dual Hall current sensor that improves the output accuracy of products.

[0007] The specific technical solution is as follows:

[0008] A dual Hall effect current sensor for improving product output accuracy includes:

[0009] The magnetic core coil is made of silicon steel, and the coil is made of pure copper enameled wire.

[0010] Two Hall effect sensors;

[0011] Operational amplifier;

[0012] Air gaps are symmetrically located on both sides of the magnetic core, and two Hall sensors are installed horizontally opposite each other in the air gaps to detect the magnetic field strength.

[0013] The signal output terminals Vout of the two Hall sensors are connected to the positive input terminal and the inverting input terminal of the operational amplifier, respectively, and the reference terminal VREF is connected to a capacitor and then grounded.

[0014] In a preferred embodiment of this utility model, the magnetic core is a ring or U-shaped structure, the air gap is located on both sides of the magnetic core, and the sensing surfaces of the two Hall sensors face the central axis of the magnetic core.

[0015] As a preferred embodiment of this utility model, a filtering circuit is also included, wherein the filtering circuit is connected in series between the signal output terminal of the Hall sensor and the input terminal of the operational amplifier to filter interference signals.

[0016] As a preferred embodiment of this utility model, the operational amplifier is configured in differential amplification mode to differentially amplify the output signals of the two Hall sensors.

[0017] As a preferred embodiment of this utility model, it also includes an external measuring resistor, and the output terminal of the operational amplifier is grounded through the measuring resistor, which is used to convert the current signal into a voltage signal.

[0018] As a preferred embodiment of this utility model, the capacitor connected in parallel between the reference terminal of the Hall sensor and ground is an electrolytic capacitor or a ceramic capacitor with a capacitance of 10nF-100μF.

[0019] As a preferred embodiment of this utility model, the two Hall sensors are of the same model and have a sensitivity error of less than ±1%.

[0020] This utility model has the following beneficial effects:

[0021] 1. Significantly improved resistance to position shift: The combination of dual Hall symmetrical detection and differential amplification greatly reduces the sensor's sensitivity to changes in the position of the primary current. Even if the current deviates from the center position of the sensor, the signal difference between the two Hall sensors can be effectively canceled through circuit processing, ensuring stable output accuracy.

[0022] 2. Higher magnetic field detection accuracy: Dual Hall elements sense the magnetic field simultaneously. Through signal superposition or differential calculation, the actual magnetic flux change in the magnetic core can be reflected more accurately. Compared with single Hall single-point detection, it reduces the measurement deviation caused by local magnetic field inhomogeneity.

[0023] 3. Enhanced environmental adaptability: The synergistic effect of the filter circuit, capacitor voltage regulator, and symmetrical structure effectively suppresses common industrial noises such as electromagnetic interference and power fluctuations, improving the reliability of the sensor in complex environments.

[0024] 4. Dynamic performance optimization: The optimization of the magnetic core coil parameters (such as cross-sectional area and number of turns) makes the sensor less prone to saturation when measuring high current, and the secondary side compensation mechanism responds faster, making it suitable for dynamic current monitoring scenarios. Attached Figure Description

[0025] Figure 1 The graph shows the rate of change of the output accuracy of this utility model and a single Hall effect sensor when rotated one revolution at a position 40mm in the center of the primary side current distance sensor.

[0026] Figure 2 A circuit diagram of a single Hall effect sensor provided for an embodiment of this utility model;

[0027] Figure 3 The circuit diagram of the dual Hall effect provided for the embodiment of this utility model. Detailed Implementation

[0028] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0029] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the scope of this patent. To better illustrate the embodiments of this utility model, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0030] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0031] In the description of this utility model, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating the connection relationship between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; 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 refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] Example

[0033] The dual Hall effect current sensor provided in this embodiment improves the output accuracy of the product, such as... Figures 1-3 As shown, it includes: a magnetic core coil, two Hall sensors, and an operational amplifier, wherein:

[0034] The magnetic core of the coil is made of silicon steel, and the coil itself is made of pure copper enameled wire.

[0035] Air gaps are symmetrically positioned on both sides of the magnetic core, and two Hall sensors are installed horizontally opposite each other in the air gaps to detect the magnetic field strength.

[0036] The signal output terminals Vout of the two Hall sensors are connected to the positive and negative input terminals of the operational amplifier, respectively, and the reference terminal VREF is connected to a capacitor and then grounded.

[0037] The dual Hall current sensor, which improves the output accuracy of the product by adopting the above technical solution, can simultaneously detect the magnetic field strength on both sides of the magnetic core by setting air gaps at symmetrical positions on both sides of the magnetic core and placing the dual Hall sensors horizontally opposite each other. By superimposing or differentially processing the dual Hall signals, the fluctuation of the magnetic field strength on one side caused by the position shift of the primary side current is canceled out, so that the output accuracy of the sensor is not affected by the position change of the primary side current. The amplification of the dual Hall signals by the operational amplifier can enhance the signal stability and improve the detection sensitivity.

[0038] Specifically, in this embodiment, the magnetic core is a ring-shaped or U-shaped structure, with air gaps located on both symmetrical sides of the magnetic core, and the sensing surfaces of the two Hall sensors facing the central axis of the magnetic core. The ring-shaped or U-shaped magnetic core structure concentrates the magnetic field generated by the primary current, the symmetrical air gap design ensures that the dual Hall sensors are in a uniform magnetic field region, and the sensing surfaces facing the central axis allow the Hall sensors to directly capture the main magnetic field signal, reducing interference from edge magnetic fields and further improving the symmetry and accuracy of magnetic field detection.

[0039] Specifically, in this embodiment, the dual Hall current sensor that improves the product's output accuracy also includes a filtering circuit. A filtering circuit is connected in series between the signal output terminal of the Hall sensor and the input terminal of the operational amplifier to filter interference signals. The filtering circuit can filter high-frequency noise (such as electromagnetic interference in industrial environments) in the Hall sensor's output signal, preventing interference signals from entering the operational amplifier and causing amplification errors, thus improving signal purity and indirectly enhancing the stability of the sensor's output accuracy.

[0040] Specifically, in this embodiment, the operational amplifier is configured in differential amplification mode to differentially amplify the output signals of the two Hall sensors. Differential amplification mode extracts the difference between the output signals of the two Hall sensors, suppressing common-mode interference (such as drift caused by changes in ambient temperature or nonlinear errors in the magnetic core), and amplifying the magnetic field difference signal caused by changes in the primary current position. This significantly enhances the robustness of the sensors to changes in current position and makes the output accuracy more stable.

[0041] Specifically, in this embodiment, the dual Hall effect current sensor that improves the product's output accuracy also includes an external measuring resistor. The output of the operational amplifier is grounded through the measuring resistor to convert the current signal into a voltage signal. By linearly converting the current signal output by the operational amplifier into a voltage signal through the external measuring resistor, it is convenient for backend acquisition devices (such as oscilloscopes and data acquisition cards) to directly measure it, simplifying the signal processing flow. At the same time, through precise matching of the resistor values, the output linearity of the sensor can be further calibrated.

[0042] Specifically, in this embodiment, the capacitor connected in parallel between the reference terminal of the Hall sensor and ground is an electrolytic capacitor or a ceramic capacitor with a capacitance of 10nF-100μF. Connecting the capacitor (electrolytic or ceramic) in parallel with the reference terminal stabilizes the reference voltage (VREF) of the Hall sensor, suppresses power supply ripple interference on the operating point of the Hall device, ensures the Hall sensor operates under a stable reference voltage, and improves the baseline stability of its output signal.

[0043] Specifically, in this embodiment, the two Hall sensors are of the same model and have a sensitivity error of less than ±1%. By selecting Hall sensors of the same model with a sensitivity error of less than ±1%, the influence of the differences in the parameters of the dual Hall elements on the detection results can be minimized, ensuring the consistency of magnetic field detection on both sides, avoiding additional errors introduced by individual element differences, and enhancing the anti-offset effect of the dual Hall symmetrical design.

[0044] In summary, the dual Hall current sensor provided in this embodiment, which improves the output accuracy of the product, has the following advantages:

[0045] 1. Significantly improved resistance to position shift: The combination of dual Hall symmetrical detection and differential amplification greatly reduces the sensor's sensitivity to changes in the position of the primary current. Even if the current deviates from the center position of the sensor, the signal difference between the two Hall sensors can be effectively canceled through circuit processing, ensuring stable output accuracy.

[0046] 2. Higher magnetic field detection accuracy: Dual Hall elements sense the magnetic field simultaneously. Through signal superposition or differential calculation, the actual magnetic flux change in the magnetic core can be reflected more accurately. Compared with single Hall single-point detection, it reduces the measurement deviation caused by local magnetic field inhomogeneity.

[0047] 3. Enhanced environmental adaptability: The synergistic effect of the filter circuit, capacitor voltage regulator, and symmetrical structure effectively suppresses common industrial noises such as electromagnetic interference and power fluctuations, improving the reliability of the sensor in complex environments.

[0048] 4. Dynamic performance optimization: The optimization of the magnetic core coil parameters (such as cross-sectional area and number of turns) makes the sensor less prone to saturation when measuring high current, and the secondary side compensation mechanism responds faster, making it suitable for dynamic current monitoring scenarios.

[0049] Working principle:

[0050] 1. Magnetic field generation and concentration: When the primary current (Ip) passes through the conductor, it generates a ring-shaped magnetic field. The magnetic core (made of silicon steel) concentrates this magnetic field and guides it into the magnetic circuit, so that the magnetic field is concentrated in the air gap region on both sides of the magnetic core.

[0051] 2. Dual Hall Symmetrical Detection: Two Hall sensors are horizontally mounted opposite each other in the air gap on both sides of the magnetic core, with their sensing surfaces facing the central axis of the magnetic core, to detect the magnetic field strength at the air gap. When the primary current is centered, the magnetic field strength detected by the Hall sensors on both sides is equal; when the current position is offset, the magnetic field strength on both sides will differ.

[0052] 3. Signal processing and amplification:

[0053] The Hall sensor converts the magnetic field strength into a voltage signal (Vout). After the noise is filtered out by the filter circuit, the signal is input to the positive and negative input terminals of the operational amplifier.

[0054] The operational amplifier operates in differential amplification mode, amplifying the difference between the two Hall signals and suppressing common-mode signals (such as environmental interference). If the current position shifts, causing unequal magnetic fields on both sides, the differential output signal reflects this difference and drives subsequent circuitry to adjust; if the current position is centered, the differential output is zero or a stable value, ensuring that the output signal is only related to the current magnitude.

[0055] 4. Signal Conversion and Output: The current signal output by the operational amplifier is converted into a voltage signal through an external measuring resistor for detection by the back-end equipment. This voltage signal linearly reflects the intensity and direction of the primary current.

[0056] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A dual Hall effect current sensor for improving product output accuracy, characterized in that, include: The magnetic core coil is made of silicon steel, and the coil is made of pure copper enameled wire. Two Hall effect sensors; Operational amplifier; Air gaps are symmetrically located on both sides of the magnetic core, and two Hall sensors are installed horizontally opposite each other in the air gaps to detect the magnetic field strength. The signal output terminals Vout of the two Hall sensors are connected to the positive input terminal and the inverting input terminal of the operational amplifier, respectively, and the reference terminal VREF is connected to a capacitor and then grounded.

2. The dual Hall current sensor for improving product output accuracy according to claim 1, characterized in that, The magnetic core has a ring or U-shaped structure, the air gap is located on both sides of the magnetic core, and the sensing surfaces of the two Hall sensors face the central axis of the magnetic core.

3. The dual Hall current sensor for improving product output accuracy according to claim 1, characterized in that, It also includes a filtering circuit, which is connected in series between the signal output terminal of the Hall sensor and the input terminal of the operational amplifier to filter out interference signals.

4. The dual-Hall current sensor for improving product output precision according to claim 1, wherein The operational amplifier is configured in differential amplification mode to differentially amplify the output signals of the two Hall sensors.

5. The dual-Hall current sensor for improving product output precision according to claim 1, wherein It also includes an external measuring resistor, the output of the operational amplifier is grounded through the measuring resistor, and is used to convert the current signal into a voltage signal.

6. The dual-Hall current sensor for improving product output accuracy according to claim 1, wherein The capacitor connected in parallel between the reference terminal of the Hall sensor and ground is an electrolytic capacitor or a ceramic capacitor with a capacitance of 10nF-100μF.

7. The dual-Hall current sensor for improving output accuracy of a product according to any one of claims 1 to 6, characterized by, The two Hall sensors are of the same model and have a sensitivity error of less than ±1%.

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