A low-power current optical sensor

Abstract

This invention relates to the field of current transformer technology and discloses a low-power current optical sensor, comprising a housing with an internal mounting cavity. A polarizer and an analyzer are fixedly mounted inside the mounting cavity. A conversion wheel is rotatably mounted inside the mounting cavity, and multiple sets of magneto-optical glass are fixedly mounted on the surface of the conversion wheel in a ring array on its outer circumference. The lengths of the multiple sets of magneto-optical glass are different. The current optical sensor proposed in this invention, by incorporating a rotatable conversion wheel within the sensor housing and mounting multiple sets of magneto-optical glass of different lengths on its surface, allows for adjustment of the response amplitude during use. This is achieved by switching the positions of the magneto-optical glass, causing the light emitted from the polarizer to pass through different lengths of magneto-optical glass before reaching the analyzer, thereby improving the sensor's response sensitivity and system signal-to-noise ratio. This allows the sensor to be adjusted according to different detection objects, significantly enhancing its applicability.

Description

Technical Field

[0001] This invention relates to the field of current transformer technology, and more particularly to a low-power current optical sensor. Background Technology

[0002] Electromagnetic current transformers have drawbacks such as easy magnetic saturation under overcurrent, insufficient bandwidth, and residual magnetism that greatly affects the transient error of the current transformer. Optical current sensors, which are transformers based on the Faraday magneto-optical effect, offer great potential for application in power systems due to their good electrical insulation performance, excellent radiation resistance, and extremely fast frequency response.

[0003] To address the issue of temperature drift in measurement accuracy present in current optical current transformers, patent document CN102495260B discloses a temperature drift-compensated optical current transformer and its current compensation method. The transformer includes a solenoid-type self-inductance sensor. The optical sensor is connected to the solenoid-type self-inductance sensor via a polarization-maintaining fiber. The solenoid-type self-inductance sensor is connected to a signal processing unit via a multimode fiber. The signal processing unit is also connected to the optical sensor via a multimode fiber. The temperature drift current compensation method involves: representing the Faraday rotation angle generated by the linearly polarized light from the optical sensor using the measured current; representing the Faraday rotation angle generated by the linearly polarized light from the solenoid-type self-inductance sensor using a compensation current; and deriving the expression for the output voltage based on the expression for the rotation angle, thus demonstrating the achievement of primary current measurement.

[0004] According to the Faraday magneto-optical effect, when linearly polarized light propagates in a medium, if a strong magnetic field is applied parallel to the direction of light propagation, the direction of light vibration will be deflected. The deflection angle ψ is proportional to the product of the magnetic induction intensity B and the length L of the light passing through the medium, i.e., ψ = VBL, and the proportionality constant V is called the Field constant. Since the magnetic field is caused by alternating current, ψ can be further expressed as ψ = ψ0sin(ωt), where ψ0 is the modulation amplitude of the Faraday rotation angle.

[0005] According to Malus's law, I2 = I1cos 2 In the formula, I2 is the intensity of the incident linearly polarized light, I1 is the intensity of the transmitted light (neglecting the absorption of the transmitted light by the analyzer), and θ is the angle between the transmission axes of the polarizer and the analyzer. By measuring I2, the alternating current i(t) = sin(ωt) in the generated magnetic field can be indirectly measured. This is the basic principle of optical current sensors.

[0006] See reference: Lin Sen, Du Mingming, Wang Shibin. Research on response characteristics of optical current sensor based on MR3-2 magneto-optical glass [J]. Electrical Application, 2016, 35(15):70-74. Increasing the magnetic field strength B and / or the length L of light passing through the medium can improve the response amplitude, thereby improving the sensor's response sensitivity and system signal-to-noise ratio. In actual detection, the current to be measured is constant, the magnetic field strength B remains unchanged, and the length L of light passing through the medium in existing optical current sensors is fixed, resulting in the response amplitude being unadjustable under different detection scenarios, which greatly reduces the applicability of optical current sensors. Summary of the Invention

[0007] The purpose of this invention is to address the limitation in the application scenarios of existing optical current sensors, where the length L of light passing through the medium cannot be adjusted as needed. Therefore, this invention proposes a low-power current optical sensor.

[0008] To achieve the above objectives, the present invention employs the following technical solution: a low-power current optical sensor, comprising a housing, wherein an installation cavity is provided inside the housing, and a polarizer and an analyzer are fixedly installed inside the installation cavity. A conversion wheel is rotatably installed inside the installation cavity, and multiple sets of magneto-optical glass are fixedly installed on the surface of the conversion wheel. The multiple sets of magneto-optical glass are arranged in a ring array on the outer circumference of the conversion wheel, and the multiple sets of magneto-optical glass have different lengths. The polarizer and the analyzer are arranged opposite to each other. When the conversion wheel rotates, each magneto-optical glass rotates to the area formed between the polarizer and the analyzer. A driving mechanism is provided inside the housing, which drives the conversion wheel to rotate at a fixed angle, thereby adjusting the response amplitude and improving the sensor's response sensitivity and the system signal-to-noise ratio.

[0009] Preferably, the mounting cavity is a vacuum cavity, and a connecting shaft is fixedly installed at the axis of the conversion wheel. The two ends of the connecting shaft are rotatably connected to the two end faces of the mounting cavity, respectively. Each set of magneto-optical glass includes a first glass block and a second glass block. The cross-section and length of the first glass block and the second glass block are equal. Several first glass blocks and second glass blocks are arranged alternately and fixedly installed on the surface of the conversion wheel.

[0010] Preferably, the first glass block and the second glass block have different Verdet constants. At different temperatures, the response amplitude characteristic curve of the first glass block is known and is a first curve, and the response amplitude characteristic curve of the second glass block is known and is a second curve.

[0011] The low-power current optical sensor measures the conductor under test. By driving the conversion wheel to rotate, the angles of each group of magneto-optical glass are switched, so that each first glass block and second glass block rotates sequentially to the area formed between the polarizer and the analyzer. Under the condition of constant incident light intensity, the deflection angle ψ of each group of magneto-optical glass is measured, and the average current of the conductor under test is calculated. By switching magneto-optical glass with different magneto-optical medium lengths and Verdet constants, a suitable rotation angle can be selected for measurement and calculation, thus expanding the detection range of the sensor.

[0012] Preferably, the low-power current optical sensor measures the conductor under test. By driving the conversion wheel to rotate, the angles of each group of magneto-optical glass are switched, so that the second glass block is rotated to the area formed between the polarizer and the analyzer. Under the condition of constant incident light intensity, at least two groups of response amplitudes Vx of the second glass blocks are measured. The simulated amplitude characteristic curve plotted from the measured response amplitudes Vx of the second glass blocks is the third curve. The second curve with the same slope as the third curve is selected as the compensation curve. The current value of the conductor under test is obtained according to the compensation curve. This design realizes the use of the current value corresponding to the second curve to represent the current under test, compensates for the influence of temperature on the measured results, and solves the problem of temperature change affecting measurement accuracy.

[0013] Preferably, the drive mechanism includes an adjustment disk, a sealed cavity is provided inside the housing, the adjustment disk is rotatably disposed in the sealed cavity, a connecting shaft extends into the sealed cavity and is fixedly connected to the adjustment disk, and also includes a servo motor and a drive disk. The servo motor is fixedly installed inside the housing, and the drive disk is fixedly installed on the rotating end of the servo motor and is located outside the sealed cavity. Several magnetic blocks are embedded in the opposing surfaces of the drive disk and the adjustment disk. The drive disk and the adjustment disk are magnetically attracted to each other through the magnetic blocks. A battery pack is provided inside the housing to provide power to the servo motor.

[0014] The upper side of the housing is fitted with a clamp by bolts, which fixes the housing to the surface of the conductor to be tested. This current optical sensor does not require a constant temperature control mechanism, thus reducing its power and energy consumption.

[0015] The present invention has the following beneficial effects:

[0016] 1. The low-power current optical sensor proposed in this invention uses a rotatable conversion wheel inside the sensor housing. The surface of the conversion wheel is provided with multiple sets of magneto-optical glass of different lengths. During use, the position of the magneto-optical glass is switched so that the light emitted by the polarizer passes through the magneto-optical glass of different lengths and reaches the analyzer, thereby adjusting the response amplitude, improving the sensor's response sensitivity and system signal-to-noise ratio. This allows the sensor to be adjusted according to different detection objects, greatly improving its applicability.

[0017] 2. The low-power current optical sensor proposed in this invention uses first and second glass blocks with different Verdet constants. Each group of magneto-optical glass includes both first and second glass blocks. The polarization direction of light rotating as it passes through the magneto-optical medium depends on the length of the magneto-optical medium and the Verdet constant. This allows the sensor to measure a wide range of magnetic field strength. By switching between magneto-optical glass blocks with different magneto-optical medium lengths and Verdet constants, a suitable rotation angle can be selected for measurement and calculation, thus expanding the sensor's detection range.

[0018] 3. The low-power current optical sensor proposed in this invention uses MR3-2 novel magneto-optical glass as the second glass block. The amplitude characteristic curve of MR3-2 novel magneto-optical glass is a straight line, and the slope of the straight line can be used to measure the magnitude of its response amplitude. Moreover, the rate of change of its response amplitude with temperature is basically consistent. Taking advantage of the temperature sensitivity of the second glass block, before use, the second curve of the second glass block is measured at different temperatures under ideal laboratory conditions. During use, the third curve of the second glass block is obtained through actual measurement. The current value of the conductor to be measured is obtained from the second curve whose slope is equal to that of the third curve. This design realizes the use of the current value corresponding to the second curve to represent the current to be measured, compensates for the influence of temperature on the actual measurement results, and solves the problem of temperature change affecting measurement accuracy. This current optical sensor does not require a constant temperature control mechanism, reducing its power and energy consumption. Attached Figure Description

[0019] Figure 1 This is a partial cross-sectional three-dimensional structural diagram of the current optical sensor proposed in this invention;

[0020] Figure 2 This is a three-dimensional structural diagram of the conversion wheel proposed in this invention;

[0021] Figure 3 This is a schematic diagram of the cross-sectional structure of the current optical sensor proposed in this invention;

[0022] Figure 4 This is a schematic diagram illustrating the principle of the Faraday magneto-optical effect.

[0023] Figure 5 A schematic diagram of the first curve representing the response amplitude characteristics;

[0024] Figure 6 The second curve representing the response amplitude characteristic is shown in the diagram. Figure 1 ;

[0025] Figure 7 The second curve representing the response amplitude characteristic is shown in the diagram. Figure 2 .

[0026] In the diagram: 1. Housing; 2. Mounting cavity; 3. Conversion wheel; 4. Magneto-optical glass; 5. Polarizer; 6. Analyzer; 7. Connecting shaft; 8. First glass block; 9. Second glass block; 10. First curve; 11. Second curve; 12. Wire to be tested; 13. Adjustment disc; 14. Servo motor; 15. Drive disc; 16. Magnetic block; 17. Clamp; 18. Third curve. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0028] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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, they should not be construed as limitations on this invention.

[0029] Reference Figures 1-7 A low-power current optical sensor includes a housing 1, with an installation cavity 2 inside the housing 1. A polarizer 5 and an analyzer 6 are fixedly installed inside the installation cavity 2. A laser is connected to the polarizer 5 via an optical fiber, and the analyzer 6 is connected to a photoelectric probe via an optical fiber. The electrical signal generated by the photoelectric probe is processed by a data acquisition card and imported into a computer. This is a conventional setup and will not be described in detail here. A conversion wheel 3 is rotatably installed inside the installation cavity 2. Specifically, the installation cavity 2 is a vacuum cavity. A connecting shaft 7 is fixedly installed at the axis of the conversion wheel 3, and the two ends of the connecting shaft 7 are rotatably connected to the two end faces of the installation cavity 2.

[0030] like Figure 2 As shown, multiple sets of magneto-optical glass 4 are fixedly mounted on the surface of the conversion wheel 3. These sets of magneto-optical glass 4 are arranged in a ring array on the outer circumference of the conversion wheel 3. The lengths of the multiple sets of magneto-optical glass 4 are different, such as... Figure 2 As shown, the lengths of multiple sets of magneto-optical glass 4 increase sequentially. The polarizer 5 and the analyzer 6 are arranged opposite each other. When the conversion wheel 3 rotates, each magneto-optical glass 4 rotates to the area formed between the polarizer 5 and the analyzer 6. The polarized light emitted by the polarizer 5 passes through the magneto-optical glass 4 and then reaches the analyzer 6. The vacuum cavity can ensure that the light propagates between the polarizer 5 and the analyzer 6, reduce scattering, and at the same time reduce the influence of the external temperature on the magneto-optical glass 4.

[0031] A clamp 17 is bolted to the upper side of the housing 1, which fixes the housing 1 to the surface of the conductor 12 to be tested. A drive mechanism is provided inside the housing 1, which drives the conversion wheel 3 to rotate at a fixed angle. The drive mechanism includes an adjustment plate 13. A sealed cavity is opened inside the housing 1. The adjustment plate 13 is rotatably set in the sealed cavity. The connecting shaft 7 extends into the sealed cavity and is fixedly connected to the adjustment plate 13.

[0032] The drive mechanism also includes a servo motor 14 and a drive disk 15. The servo motor 14 is fixedly installed inside the housing 1, and the drive disk 15 is fixedly installed on the rotating end of the servo motor 14, with the drive disk 15 located outside the sealed cavity. Several magnetic blocks 16 are embedded in the opposing surfaces of the drive disk 15 and the adjusting disk 13. Figure 3 The drive disk 15 and the adjustment disk 13 are magnetically attracted to each other by the magnetic block 16. The housing 1 is equipped with a battery pack that provides power to the servo motor 14. When the servo motor 14 rotates, it drives the conversion wheel 3 to rotate at a fixed angle or switch its rotation direction.

[0033] In this embodiment, each set of magneto-optical glass 4 includes a first glass block 8 and a second glass block 9. The cross-section and length of the first glass block 8 and the second glass block 9 are equal. Several first glass blocks 8 and second glass blocks 9 are arranged alternately and fixedly installed on the surface of the conversion wheel 3, such as... Figure 2 As shown.

[0034] The Verdet constants of the first glass block 8 and the second glass block 9 are different. The Verdet constant of the magneto-optical glass 4 is related to the properties of the medium, the wavelength of the light source, the ambient temperature, etc. The Verdet constants of the first glass block 8 and the second glass block 9 are tested by experiments. For the specific measurement method, please refer to the reference: Zhang Guangtai, Wu Fuquan, Xu Liguo, et al. Precise measurement of the Verdet constant of magneto-optical glass [J]. Laser Journal, 2013, 34(01):48-49. The Verdet constants of the first glass block 8 and the second glass block 9 are known.

[0035] According to Faraday's magneto-optical effect, when linearly polarized light propagates in a medium, if a strong magnetic field is applied parallel to the direction of light propagation, the direction of light vibration will be deflected. The deflection angle ψ is proportional to the product of the magnetic induction intensity B and the length L of the light passing through the medium, i.e., ψ = VBL. The proportionality constant V is called the Field constant. Figure 4 As shown;

[0036] When the current optical sensor measures the current of the wire 12 under test, the magnetic induction intensity B is caused by the wire 12 under test. Then ψ can be further expressed as ψ=ψ0sin(ωt), where ψ0 is the modulation amplitude of the Faraday rotation angle.

[0037] According to Malus's law, I2 = I1cos 2 In the formula, I2 is the intensity of the incident linearly polarized light, I1 is the intensity of the transmitted light (the absorption of the transmitted light by the analyzer 6 is negligible), and θ is the angle between the transmission axes of the polarizer and the analyzer. By measuring I2, the alternating current i(t) = sin(ωt) in the generated magnetic field can be indirectly measured. This is the basic principle of optical current sensors and is common knowledge, so it will not be elaborated here.

[0038] When the current optical sensor measures the current of the conductor 12 under test, according to the Faraday magneto-optical effect, with the magnetic induction intensity B and Verdet constant being constant, the length L of the light passing through the medium increases, that is, the length of the magneto-optical glass 4 is increased, which can improve the response amplitude, thereby achieving the effect of improving the response sensitivity and the system signal-to-noise ratio.

[0039] The low-power current optical sensor proposed in this invention features a rotatable conversion wheel 3 inside the sensor housing 1. The surface of the conversion wheel 3 is provided with multiple sets of magneto-optical glass 4 of different lengths. During use, the position of the magneto-optical glass 4 is switched so that the light emitted by the polarizer 5 passes through the magneto-optical glass 4 of different lengths and reaches the analyzer 6, thereby adjusting the response amplitude, improving the sensor's response sensitivity and system signal-to-noise ratio. This allows the sensor to be adjusted according to different detection objects, greatly improving its applicability.

[0040] The current optical sensor measures the conductor 12 under test. By driving the conversion wheel 3 to rotate, the angles of each group of magneto-optical glass 4 are switched, so that each first glass block 8 and second glass block 9 are rotated sequentially to the area formed between the polarizer 5 and the analyzer 6. Under the condition that the incident light intensity is constant, the deflection angle ψ of each group of magneto-optical glass 4 is measured respectively, and the average current of the conductor 12 under test is calculated.

[0041] By setting different first glass blocks 8 and second glass blocks 9 with different Verdet constants, each group of magneto-optical glass 4 includes a first glass block 8 and a second glass block 9. The polarization direction of light passing through the magneto-optical medium rotates, and the rotation angle depends on the length of the magneto-optical medium and the Verdet constant. This allows the sensor to measure a wide range of magnetic field strength. By switching between magneto-optical glass 4 with different magneto-optical medium lengths and Verdet constants, a suitable rotation angle can be selected for measurement and calculation, thus expanding the sensor's detection range.

[0042] In this embodiment, the second glass block 9 uses MR3-2 novel magneto-optical glass. The response characteristics of the first glass block 8 and the second glass block 9 under AC sinusoidal excitation were experimentally studied using a Faraday magneto-optical effect experimental platform. The response characteristics include: response waveform, amplitude characteristics, frequency characteristics, and temperature characteristics. Measurements show that the response waveform amplitude characteristic curve of the first glass block 8 at different temperatures is known, and is shown as curve 10. Figure 5 As shown in the reference: Lin Sen, Du Lin, Wang Shibin, et al. Study on electrical characteristics of optical current sensor based on Faraday magneto-optical effect [J]. Journal of Sensor Technology, 2010, 23(04): 490-495; The response amplitude characteristic curve of the second glass block 9 is known, which is the second curve 11, as shown in the reference. Figure 6 As shown in the reference: Lin Sen, Du Mingming, Wang Shibin. Research on response characteristics of optical current sensor based on MR3-2 magneto-optical glass [J]. Electrical Application, 2016, 35(15):70-74.

[0043] The current optical sensor measures the conductor 12 under test. By driving the conversion wheel 3 to rotate, it switches the angles of each group of magneto-optical glass 4, causing the second glass block 9 to rotate to the area formed between the polarizer 5 and the analyzer 6. Under the condition of a constant incident light intensity, at least two sets of response amplitudes Vx of the second glass block 9 are measured. The simulated amplitude characteristic curve plotted from the measured response amplitudes Vx of the second glass block 9 is the third curve 18. Figure 7 As shown, the amplitude characteristic curve of the MR3-2 novel magneto-optical glass is a straight line. The slope of the straight line can be used to measure the magnitude of its response amplitude. Moreover, the rate of change of its response amplitude with temperature is basically consistent. Among them, the second curve 11, which has the same slope as the third curve 18, is selected as the compensation curve. The current value of the wire to be measured 12 is obtained according to the compensation curve. That is, the current value I4 of the wire to be measured 12 is obtained from the second curve 11, which has the same slope as the third curve 18. The sensor is affected by temperature. The current value I3 of the wire to be measured is measured through the second glass block 9. There is an error between the current value I3 and the current value I4. This error is caused by the change of the Verdet coefficient due to temperature. Since the current value I4 is measured in a temperature-controlled environment in the laboratory, it can more accurately reflect the magnitude of the current to be measured and has higher accuracy.

[0044] The low-power current optical sensor proposed in this invention uses MR3-2 novel magneto-optical glass as the second glass block 9. The amplitude characteristic curve of MR3-2 novel magneto-optical glass is a straight line, and the slope of the straight line can be used to measure the magnitude of its response amplitude. Moreover, the rate of change of its response amplitude with temperature is basically consistent. Taking advantage of the temperature sensitivity of the second glass block 9, before use, the second curve 11 of the second glass block 9 is measured at different temperatures under ideal laboratory conditions. During use, the third curve 18 of the second glass block 9 is obtained through actual measurement. The current value of the conductor 12 under test is obtained from the second curve 11, whose slope is equal to that of the third curve 18. This design realizes the use of the current value corresponding to the second curve 11 to represent the current under test, compensates for the influence of temperature on the actual measurement results, and solves the problem of temperature change affecting measurement accuracy. This current optical sensor does not require a constant temperature control mechanism, thus reducing its power and energy consumption.

[0045] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A low-power current optical sensor, comprising a housing (1), characterized in that: The housing (1) has an installation cavity (2) inside. A polarizer (5) and an analyzer (6) are fixedly installed inside the installation cavity (2). A conversion wheel (3) is rotatably installed inside the installation cavity (2). Multiple sets of magneto-optical glass (4) are fixedly installed on the surface of the conversion wheel (3). The multiple sets of magneto-optical glass (4) are arranged in a ring array on the outer circular surface of the conversion wheel (3). The multiple sets of magneto-optical glass (4) have different lengths. The polarizer (5) and the analyzer (6) are arranged opposite to each other. When the conversion wheel (3) rotates, each magneto-optical glass (4) rotates to the area between the polarizer (5) and the analyzer (6). Each set of magneto-optical glass (4) includes a first glass block (8) and a second glass block (9). The cross-section and length of the first glass block (8) and the second glass block (9) are equal. Several first glass blocks (8) and second glass blocks (9) are arranged alternately and fixedly installed on the surface of the conversion wheel (3). The first glass block (8) and the second glass block (9) have different Verdet constants. At different temperatures, the response amplitude characteristic curve of the first glass block (8) is known as the first curve (10), and the response amplitude characteristic curve of the second glass block (9) is known as the second curve (11). The housing (1) is equipped with a drive mechanism, which drives the conversion wheel (3) to rotate at a fixed angle. The low-power current optical sensor measures the conductor (12) under test. By driving the conversion wheel (3) to rotate, the angles of each group of magneto-optical glass (4) are switched, so that the second glass block (9) is rotated to the area between the polarizer (5) and the analyzer (6). Under the condition that the incident light intensity is constant, the response amplitude Vx of at least two groups of second glass blocks (9) is obtained by actual measurement. The simulated amplitude characteristic curve obtained from the actual response amplitude Vx of the second glass block (9) is the third curve (18). The current value of the conductor (12) under test is obtained from the second curve (11) whose slope is equal to that of the third curve (18).

2. The low-power current optical sensor according to claim 1, characterized in that: The mounting cavity (2) is a vacuum cavity. A connecting shaft (7) is fixedly installed at the center of the conversion wheel (3). The two ends of the connecting shaft (7) are rotatably connected to the two end faces of the mounting cavity (2).

3. A low-power current optical sensor according to claim 2, characterized in that: The low-power current optical sensor measures the conductor (12) under test. By driving the conversion wheel (3) to rotate, the angles of each group of magneto-optical glass (4) are switched, so that each first glass block (8) and second glass block (9) are sequentially rotated to the area between the polarizer (5) and the analyzer (6). Under the condition that the incident light intensity is constant, the deflection angle ψ of each group of magneto-optical glass (4) is measured, and the average current of the conductor (12) under test is calculated.

4. A low-power current optical sensor according to claim 3, characterized in that: The drive mechanism includes an adjustment disc (13), and a sealed cavity is provided inside the housing (1). The adjustment disc (13) is rotatably disposed in the sealed cavity, and the connecting shaft (7) extends into the sealed cavity and is fixedly connected to the adjustment disc (13).

5. A low-power current optical sensor according to claim 4, characterized in that: The drive mechanism also includes a servo motor (14) and a drive disk (15). The servo motor (14) is fixedly installed inside the housing (1), and the drive disk (15) is fixedly installed on the rotating end of the servo motor (14). Several magnetic blocks (16) are embedded in the opposite surfaces of the drive disk (15) and the adjustment disk (13). The drive disk (15) and the adjustment disk (13) are magnetically attracted to each other through the magnetic blocks (16). A battery pack for providing power to the servo motor (14) is provided inside the housing (1).

6. A low-power current optical sensor according to any one of claims 1-5, characterized in that: The upper side of the housing (1) is fitted with a clamp (17) by bolts, and the housing (1) is fixedly installed on the surface of the conductor (12) to be tested by the clamp (17).

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