Non-contact AC / DC detection probe, detection method and application

Abstract

The present invention discloses a non-contact AC / DC detection probe, its detection method, and its application. By using a Hall effect sensor module, it overcomes the limitation of traditional induction coils, which could only detect AC current. This probe can directly measure AC / DC current on a single wire or a cable composed of two or more wires. During detection, position adjustment aligns the detection orifice with the optimal position of the target wire, thus allowing the electromagnetic signal generated by the target wire to be captured by the Hall effect sensor module.Electromagnetic signals generated by other, untargeted wires are blocked by a protective metal casing, allowing the measurement of electrical parameters such as current, voltage, frequency, duty cycle, phase, harmonics, and frequency variation signals without the need to strip or separate the wires from the cable. Operation is simple and convenient. Furthermore, the absence of a traditional silicon steel structure allows for extended operation without accuracy issues due to overheating, making the probe suitable for use with styli, multimeters, clamp meters, and other measuring instruments, with a wide range of applications. Figure: No. 3.

Description

Title of invention: Non-contact AC / DC detection probe, detection method and application Technical field

[0001] The present invention relates to the field of measuring instruments, and in particular to a non-contact AC / DC detection probe as well as its detection method and its application. STATE OF THE ART

[0002] There are many methods for measuring current, among which the most common are shunts, current transformers, Hall effect sensors, magnetically amplified current comparators, and magnetically modulated current comparators. In the field of electrical technology, it is often necessary to measure current accurately, quickly, and conveniently. When it comes to field applications, the need to break the circuit to connect the current measuring device is not only tedious and inefficient, but also dangerous and non-compliant with safety standards, especially when measuring current on electrical devices in operation. In this context, the use of a clamp-on current measuring device is much more convenient, as it allows current to be measured without breaking the circuit.

[0003] The Hall effect-based current clamp meter is one of the most widely used current measuring instruments currently. A Hall effect-based current clamp places a Hall element in an air gap of a magnetic core, and the Hall element measures the magnetic field strength in that air gap.

[0004] As disclosed in Chinese Patent Publication No. CN112816756A titled "Alternating Current Measuring Device Using Hall Effect Sensor", a current measuring device and a current clamp are disclosed, comprising: a coil, an operational amplifier, an adder, a Hall effect sensor and an iron core. The coil is connected to the output of the operational amplifier and the input of the adder; the input of the operational amplifier is connected to the Hall effect sensor to collect and amplify the signals of the Hall effect sensor. Although this device can measure both alternating current and direct current, it can only measure one wire at a time.When a cable (except shielded cables) is made up of two or more wires, the current clamp that simultaneously grasps two wires (such as phase and neutral) detects opposing magnetic fields that cancel each other out, producing a resultant zero magnetic field and a zero current reading, which does not reflect . the actual current in the circuit. Therefore, it is necessary to strip the insulating layer of the cable and separate the wires to measure them individually, which is not only laborious and inefficient, but also problematic in terms of safety of use. CONTENT OF THE INVENTION

[0005] To overcome the above-mentioned shortcomings, the objective of the present invention is to provide a simple-to-use, non-contact AC / DC detection probe capable of directly measuring AC / DC current on unshielded cables, as well as its detection method.

[0006] To achieve this objective, the technical solution proposed by the present invention is as follows:

[0007] A non-contact AC / DC sensing method, comprising the following steps:

[0008] Constructing a confined and electromagnetically shielded space provided with a sensing hole allowing electromagnetic signals in a specific direction to enter this space. A Hall effect sensor module is installed in this space to pick up the electromagnetic signals passing through the sensing hole.

[0009] When detecting a single wire, bring the detection hole close without touching the wire, so that the electromagnetic signal generated by the AC / DC current flowing through the wire passes through the detection hole to enter the shielding space and be picked up by the Hall sensor module, which then outputs a corresponding voltage signal.

[0010] When detecting an untwisted cable composed of two or more wires, bring the detection hole close without touching the cable, and then rotate the detection hole around the untwisted cable to successively orient it toward each of the wires, so that the electromagnetic signal generated by the AC / DC current flowing through the target wire passes through the detection hole to enter the shielding space and be picked up by the Hall sensor module, which then outputs a corresponding voltage signal.

[0011] When detecting a twisted cable composed of two or more wires, bring the detection hole close without touching the cable, then rotate the detection hole around the twisted cable and / or move along the longitudinal axis of the cable, so that the electromagnetic signal generated by the AC / DC current flowing through the target wire passes through the detection hole to enter the shielding space and be picked up by the Hall sensor module, which then outputs a corresponding voltage signal.

[0012] The voltage signal output by the Hall effect sensor module is processed and analyzed by an MCU main chip to obtain relevant electrical parameters, including current, voltage, frequency, duty cycle, phase, harmonics and frequency variation signals.

[0013] A non-contact AC / DC sensor for realizing the non-contact AC / DC detection method, comprising a metal shielding case and a Hall sensor module, wherein the metal shielding case is used to create a confined space and shielded against electromagnetic interference; the metal shielding case is provided with a detection hole allowing electromagnetic signals in a specific direction to enter the shielding space; the Hall sensor module is located inside the metal shielding case, used to detect the electromagnetic signals entering through the detection hole in the metal shielding case and outputting a corresponding voltage signal.

[0014] In a preferred embodiment of the present invention, an iron rod is disposed next to the Hall effect sensor module to increase its sensitivity to variations in the magnetic field. This iron rod can improve the detection efficiency of the Hall effect sensor module, making it more sensitive and accurate.

[0015] In another preferred embodiment of the present invention, the Hall effect sensor module comprises a Hall element, a first signal amplification circuit, a second signal amplification circuit, and a noise filtering circuit. The Hall element is connected to the first signal amplification circuit, the iron rod is connected to the second signal amplification circuit, and the protective metal shell is connected to the noise filtering circuit.

[0016] In another preferred embodiment of the present invention, the iron bar is the probe of a measuring stylus, thus allowing more versatile detection with a compact volume and a wide range of applications.

[0017] A non-contact AC / DC sensing probe according to the present invention can be used with measuring styli or measuring instruments.

[0018] The advantages of the present invention are as follows: The non-contact AC / DC detection probe of the present invention is designed ingeniously and reasonably. By using a Hall sensor module, it overcomes the limitation of traditional induction coils that can only detect AC current. It can detect AC or DC current and directly measure the AC / DC current on a single wire or a cable composed of two or more wires (except shielded cables). When detecting, by rotating and / or moving the probe, the detection port is adjusted to the optimal measurement position of the target wire, thereby allowing the electromagnetic signal generated by the target wire to be picked up by the Hall sensor module. Electromagnetic signals generated by other non-target wires are blocked by a shielding metal shell to prevent interference.This allows the measurement of relevant AC / DC electrical parameters, such as current, voltage, frequency, duty cycle, phase, harmonics and frequency variation signals, without having to strip or separate the cable wires, ensuring . thus safe use. In addition, the operation is simple and convenient; the overall structure is simple and compact, eliminating the need for traditional silicon steel structures. It can work for long periods without accuracy problems due to heating, with high measurement accuracy. The probe is suitable for measuring stylus, multimeters, clamp meters and other measuring instruments, offering broad application prospects.

[0019] The present invention is explained in more detail with reference to the figures and exemplary embodiments.

[0020] THE FIGURES ARE DESCRIBED AS FOLLOWS

[0021] [Fig.l]: Diagram of the three-dimensional structure of the non-contact AC / DC detection probe according to embodiment 1 of the present invention.

[0022] [Fig.2]: Diagram of the exploded structure of the non-contact AC / DC detection probe according to embodiment 1 of the present invention.

[0023] [Fig.3]: Schematic diagram of the principle circuit of the non-contact AC / DC detection probe according to embodiment 1 of the present invention.

[0024] [Fig.4]: Diagram of the structure of the probe detecting a single wire according to embodiment 1 of the present invention (diagram 1).

[0025] [Fig.5]: Diagram of the structure of the probe detecting a single wire according to embodiment 1 of the present invention (diagram 2).

[0026] [Fig.6]: Diagram of the structure of the probe detecting an untwisted cable according to embodiment 1 of the present invention (diagram 1).

[0027] [Fig.7]: Diagram of the structure of the probe detecting an untwisted cable according to embodiment 1 of the present invention (diagram 2).

[0028] [Fig.8]: Diagram of the structure of the probe detecting a twisted cable according to embodiment 1 of the present invention (diagram 1).

[0029] [Fig.9]: Diagram of the structure of the probe detecting a twisted cable according to embodiment 1 of the present invention (diagram 2).

[0030] [Fig. 10]: Diagram of the structure of the probe detecting another type of twisted cable according to embodiment 1 of the present invention (diagram 1).

[0031] [Fig. 11]: Diagram of the structure of the probe detecting another type of twisted cable according to embodiment 1 of the present invention (diagram 2).

[0032] [Fig. 12]: Diagram of the connection ports of the main MCU chip according to the exemplary embodiment 1 of the present invention.

[0033] [Fig. 13]: Diagram of the structure of the non-contact AC / DC detection probe according to embodiment 2 of the present invention.

[0034] [Fig. 14]: Schematic diagram of the principle circuit of the non-contact AC / DC detection probe according to embodiment 2 of the present invention.

[0035] [Fig. 15]: Diagram of the structure of the product according to application example 1 of the present invention.

[0036] [Fig. 16]: Diagram of the structure of the product according to application example 2 of the present invention.

[0037] [Fig. 17]: Diagram of the structure of the product according to application example 3 of the present invention.

[0038] [Fig. 18]: Diagram of the structure of the product according to application example 4 of the present invention.

[0039] [Fig. 19]: Diagram of the structure of the product according to application example 5 of the present invention.

[0040] [Fig.20]: Diagram of the structure of the product according to application example 6 of the present invention.

[0041] [Fig.21]: Diagram of the structure of the product according to application example 7 of the present invention.

[0042] [Fig.22]: Diagram of the structure of the product according to application example 8 of the present invention. SPECIFIC METHODS OF IMPLEMENTATION

[0043] Embodiment example 1: Refer to Figures 1, 2 and 3. The present embodiment provides a non-contact AC / DC detection probe 10, comprising a protective metal shell 1 and a Hall sensor module 2. The protective metal shell 1 is used to create a confined space shielded against electromagnetic interference. The protective metal shell 1 is provided with a detection port 3 allowing electromagnetic signals in a specific direction to enter the shielding space. The Hall sensor module 2 is located inside the protective metal shell 1 and is used to detect electromagnetic signals entering through the detection port 3 in the protective metal shell 1. The Hall sensor module 2 has connection terminals VDD, VSS and CVO.In this embodiment, the protective metal shell 1 has a square shape, but in other embodiments, it can also be cylindrical or have other shapes.

[0044] The Hall effect sensor module comprises a Hall element, a first signal amplification circuit, a second signal amplification circuit and a noise filtering circuit. The Hall element is connected to the first signal amplification circuit, the iron bar is connected to the second signal amplification circuit, and the protective metal shell is connected to the noise filtering circuit to eliminate unwanted noise.

[0045] The detection method of the non-contact AC / DC detection probe 10 is as follows: when detecting, a confined space shielded against interference electromagnetic signals is created by the protective metal shell 1. The sensing hole 3, located on the protective metal shell 1, allows electromagnetic signals in a specific direction to enter the shielding space, while electromagnetic signals from other directions are blocked. The width of the sensing hole 3 is preferably 2 mm, and its length is preferably between 2 and 5 mm. The Hall sensor module 2 is fixed inside the protective metal shell 1.

[0046] When detecting a single wire 6, refer to Figures 4 and 5. The single wire 6 comprises a core 61 and an insulating protective layer 62 surrounding the core 61. The detection hole 3 is brought close to the single wire without touching it, thereby allowing the electromagnetic signal generated by the AC / DC current flowing through the single wire 6 to pass through the detection hole 3 to enter the protective space and be picked up by the Hall sensor module 2, which then outputs a corresponding voltage signal.

[0047] When detecting an untwisted cable 7 composed of two parallel wires, refer to Figures 6 and 7. The detection hole 3 is brought close to the untwisted cable 7 without touching it, and then rotated around the untwisted cable 7, so as to successively orient the detection hole 3 towards each of the wires of the untwisted cable 7. Thus, when the detection hole 3 is aligned with the two wires and oriented towards the left or right wire, the electromagnetic signal generated by the AC / DC current passing through the left or right target wire can pass through the detection hole 3 to enter the protection space and be picked up by the Hall effect sensor module 2, which then outputs a corresponding voltage signal.

[0048] When detecting a twisted cable formed by two wires, refer to Figures 8 and 9. The detection hole 3 is brought close to the twisted cable 8 without touching it, and then rotated around the twisted cable 8 clockwise or counterclockwise, or moved vertically. When the detection hole 3 is aligned with the two wires, the electromagnetic signal generated by the AC / DC current flowing through the target wire located near the detection hole 3 can pass through the detection hole 3 to enter the shielding space and be picked up by the Hall sensor module 2, which then outputs a corresponding voltage signal.

[0049] When detecting a twisted cable formed of more than five wires, refer to Figures 10 and 11. The detection hole 3 is brought close to the twisted cable without touching it, and then rotated around the twisted cable to the left or right, while moving vertically along the longitudinal axis of the twisted cable. This allows the detection hole 3 to find the optimal position for measuring the target wire, because the measured values ​​increase to a maximum when the detection hole 3 is properly aligned. Thus, the electromagnetic signal generated by the AC / DC current passing through the target wire of the twisted cable passes through the sensing hole 3 to enter the protective gap and be picked up by the Hall sensor module 2, which then outputs a corresponding voltage signal.

[0050] Refer to [Fig.12]. The MCU main chip may be of the STM8L151 model or the ML54 / 56 series. The MCU main chip is connected to the non-contact AC sensing probe 10 via the terminals VDD, VSS and CVO. The non-contact AC sensing probe 10 outputs a corresponding current signal, which is processed and analyzed by the MCU main chip to obtain relevant electrical parameters, such as current, voltage, frequency, duty cycle, phase, harmonics and frequency variation signals.

[0051] Current: When a current flows through a wire, it generates a magnetic field proportional to the current intensity. This magnetic field can be picked up by the Hall effect sensor module 2, which converts it into a voltage signal. This voltage signal is then amplified by the circuit to display the load current.

[0052] Voltage: The principle of electromagnetic induction makes it possible to detect variations in the electromagnetic field, providing information on the voltage and making it possible to measure its value.

[0053] Frequency: In an AC circuit, the periodic variations of current and voltage correspond to a specific frequency. By analyzing the period and frequency of electromagnetic signals, the transmission frequency in the wire can be determined.

[0054] Duty cycle: Duty cycle refers to the proportion between the duration of the high state and the period of a periodic signal. By detecting the pulse width of the electromagnetic signal or variations in the signal intensity, the duty cycle can be analyzed and measured.

[0055] Phase: The phase of electromagnetic signals can be measured by detecting the time difference between the starting point of the signal and that of a reference signal. This is based on the time shift relationship of periodic signals, and the propagation speed of electromagnetic waves can determine the phase information.

[0056] Harmonics: By analyzing the spectrum of electromagnetic signals, harmonic components present in the wire can be detected. Harmonics are periodic signal components whose frequency is an integer multiple of the fundamental frequency. Nonlinear loads cause distortions in the current or voltage, thus generating harmonics, which can be identified and quantified by spectral analysis of electromagnetic signals.

[0057] Frequency variation signals: The variations in the magnetic field, captured by the Hall effect sensor module 2, make it possible to detect the frequency variation signals.

[0058] Example embodiment 2: Refer to Figures 13 and 14. This example embodiment provides a non-contact AC / DC detection probe whose structure is essentially similar to that of example embodiment 1. The difference lies in the fact that the probe of a measuring stylus 5 is used to replace the iron bar 4. For example, the measuring probe can be that of a multimeter, which increases the functionality of the multimeter.

[0059] A non-contact AC / DC sensing probe according to the present invention may be used with measuring styli or measuring instruments, as illustrated in the following application examples.

[0060] Application Example 1: Refer to [Fig. 15]. The non-contact AC / DC sensing probe 10 provided in embodiments 1 or 2 can be used in a multi-function sensing clamp. The non-contact AC / DC sensing probe 10 is located inside the arc-shaped concave portion of the multi-function sensing clamp.

[0061] Application Example 2: Refer to [Fig. 16]. The non-contact AC / DC sensing probe 10 provided in embodiments 1 or 2 can be used in a dual-sensing ammeter. The non-contact AC / DC sensing probe 10 is located inside the arc-shaped concave portion of the sensing head of the dual-sensing ammeter.

[0062] Application example 3: Refer to [Fig. 17]. The non-contact AC / DC detection probe 10 proposed in embodiments 1 or 2 can be used in a non-contact current clamp. The non-contact current clamp is provided with a projecting portion at the location of the jaws, where the non-contact AC / DC detection probe 10 is located. During detection, it is sufficient to bring the projecting portion close to the electrical cable to be tested.

[0063] Application Example 4: Refer to [Fig. 18]. The non-contact AC / DC detection probe 10 proposed in embodiments 1 or 2 can be used in an electrical tester. The electrical tester is equipped with a fixed test probe, and the non-contact AC / DC detection probe 10 is located inside the body of the fixed test probe. When detecting, it is sufficient to bring the body of the fixed test probe close to the electrical cable to be tested.

[0064] Application Example 5: Refer to [Fig. 19]. The non-contact AC / DC detection probe 10 proposed in embodiments 1 or 2 can be used at the probe end of a multimeter. During detection, it is sufficient to bring the probe end of the multimeter close to the electrical cable to be tested.

[0065] Application example 6: Refer to [Fig.20]. The non-contact AC / DC detection probe 10 proposed in embodiments 1 or 2 can be used at the end of a multifunction probe. During detection, it is sufficient to bring the end of the multifunction probe close to the electrical cable to be tested.

[0066] Application Example 7: Refer to [Fig.21]. The non-contact AC / DC detection probe 10 proposed in embodiment examples 1 or 2 can be used at the detection position at the head of a pen-shaped current measuring device. When detecting, it is sufficient to place the electric cable to be tested in the detection position at the head of the pen-shaped current measuring device.

[0067] Application example 8: Refer to [Fig.22]. The non-contact AC / DC detection probe 10 proposed in embodiment examples 1 or 2 can be used at the detection position at the head of a multifunction energy meter. During detection, it is sufficient to place the electrical cable to be tested in the detection position at the head of the multifunction energy meter.

[0068] The above-mentioned embodiments and applications are only preferred embodiments and applications of the present invention. The present invention cannot be exhaustive. Any technical solution adopting one of the above-mentioned embodiments or applications, or any equivalent modification based on the above-mentioned embodiments, falls within the scope of protection of the present invention.

[0069] Measuring instruments using the non-contact AC / DC sensing probe 10 of the present invention can perform AC / DC measurements directly on a single wire or on a cable composed of two or more wires (except shielded cables), in order to obtain electrical parameters such as current, voltage, frequency, duty cycle, phase, harmonics and frequency variation signals. In summary, the present invention has the following advantages: 1. It allows measuring AC / DC currents on a single wire or a cable composed of several wires (except shielded cables) without having to strip or separate the wires of the cable, thus ensuring safe use and simple and convenient handling. 2. Using Hall effect sensor module, it overcomes the limitation of traditional induction coils that could only detect AC current. It can detect AC or DC currents and obtain the corresponding electrical parameters through the processing of the main chip MCU, and then display the results. 3. The absence of traditional silicon steel structure allows for long-term operation without accuracy problems due to heating. 4. The main MCU chip can use wireless connections such as Bluetooth or Wi-Fi to share data with smartphones, tablets and computers, making operation simple and convenient.

[0070] According to the disclosures and teachings of this specification, those skilled in the art of the present invention may make modifications and variations to the embodiments described above. Therefore, the present invention is not limited to the specific embodiments disclosed and described above. Certain modifications and variations of the present invention should also be included within the scope of the claims of the present invention. Furthermore, although certain specific terms have been used in this specification, they are used solely for convenience and do not constitute any limitation of the present invention. Thus, structures and methods obtained by following the same or similar steps to the exemplary embodiments described above also fall within the scope of protection of the present invention.

Claims

Claims

1. A non-contact AC / DC detection method, characterized by the following steps: Constructing a confined space shielded against electromagnetic interference, provided with a detection hole allowing electromagnetic signals in a specific direction to enter this space. A Hall sensor module is installed in this space to pick up electromagnetic signals passing through the detection hole. When detecting a single wire, bringing the detection hole close without touching the wire, so that the electromagnetic signal generated by the AC / DC current passing through the wire passes through the detection hole to enter the shielding space and is picked up by the Hall sensor module, which then outputs a corresponding voltage signal.When detecting an untwisted cable consisting of two or more wires, bring the detection hole close without touching the cable, and then rotate the detection hole around the untwisted cable to successively point it at each of the wires, so that the electromagnetic signal generated by the AC / DC current flowing through the target wire passes through the detection hole to enter the shielding gap and be picked up by the Hall sensor module, which then outputs a corresponding voltage signal.When detecting a twisted cable consisting of two or more wires, bring the detection hole close without touching the cable, then rotate the detection hole around the twisted cable and / or move along the longitudinal axis of the cable, so that the electromagnetic signal generated by the AC / DC current flowing through the target wire passes through the detection hole to enter the shielding gap and be picked up by the Hall sensor module, which then outputs a corresponding voltage signal.

2. The non-contact AC / DC detection method according to claim 1, characterized in that: the voltage signal output by the Hall effect sensor module is processed and analyzed by an MCU main chip to obtain the relevant electrical parameters.

3. The non-contact AC / DC detection method according to claim 2, characterized in that: the electrical parameters comprise current, voltage, frequency, duty cycle, phase, harmonics and frequency variation signals.

4. A non-contact AC / DC detection sensor for performing any of the non-contact AC / DC detection methods according to claims 1 to 3, characterized in that: a shielding metal case, used to create a confined space shielded against electromagnetic interference; said shielding metal case is provided with a detection port allowing electromagnetic signals in a specific direction to enter the shielding space; a Hall effect sensor module, used to detect electromagnetic signals entering the shielding metal case through the detection port, and outputting a corresponding voltage signal.

5. The non-contact AC / DC detection sensor according to claim 4, characterized in that: an iron bar is arranged next to the Hall effect sensor module to increase its sensitivity to variations in the magnetic field.

6. The non-contact AC / DC detection sensor according to claim 5, characterized in that: the Hall effect sensor module comprises a Hall element, a first signal amplification circuit, a second signal amplification circuit and a noise filtering circuit, the Hall element being connected to the first signal amplification circuit, the iron bar being connected to the second signal amplification circuit, and the protective metal case being connected to the noise filtering circuit.

7. The non-contact AC / DC detection sensor according to claim 5, characterized in that: the iron bar is the sensor of a measuring stylus.

8. A non-contact AC / DC detection sensor according to claim 4, applied to a measuring stylus.

9. A non-contact AC / DC detection sensor according to any one of claims 4 to 7, applied to measuring instruments.

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