Non-contact AC detection probe, detection method and application

Abstract

The present invention discloses a non-contact AC detection probe, its detection method, and its application. It enables the measurement of alternating current on a cable consisting of one or more wires without direct contact. During detection, position adjustment aligns the detection orifice with the optimal position of the target wire, allowing the electromagnetic signal generated by the target wire to pass through the detection orifice and enter the protective space, where it is captured by an induction coil. The electromagnetic signals of the other, non-targeted wires are blocked by a protective metallic casing to prevent interference. This allows the measurement of AC electrical parameters, including current, voltage, frequency, duty cycle, phase, harmonics, and frequency variation signals, without the need to strip or separate the wires from the cable, thus ensuring safe operation.The device is simple and practical to use, eliminating the need for traditional silicon steel sheet structures, and can operate for extended periods without accuracy issues due to overheating. It can be used with measuring instruments such as styli, multimeters, and clamp meters, offering a wide range of applications. See Figure 1 for abbreviations.

Description

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

[0001] The present invention relates to the field of measuring instruments, and more particularly to a non-contact AC detection probe as well as its detection method and its application. Prior art technique

[0002] In order to ensure electrical safety, the conductive wires that may be exposed are protected by an insulating layer or a plastic shell. In this context, the use of traditional measurement methods requiring direct contact involves either removing the insulating layer for measurement or perforating it to reach the conductive wire, which damages the protective layer and poses a risk to electrical safety.

[0003] To overcome this problem, non-contact measuring instruments have been introduced to the market, allowing alternating current to be measured without damaging the insulating layer of the wires. However, current instruments often use closed or semi-open silicon steel probes, which are capable of measuring the alternating current of a single wire, but are ineffective for cables composed of several wires (except for shielded cables). When a current clamp surrounds two wires (e.g., phase and neutral), the magnetic fields generated cancel each other out, giving a reading of zero, which does not reflect the actual current. This requires removing the insulation layer and separating each wire for individual measurement, which is not only tedious and inefficient, but also dangerous. Content of the invention

[0004] To overcome the above-mentioned shortcomings, the objective of the present invention is to provide a non-contact AC detection probe and its detection method, which are simple to use and allow direct measurement of AC on unshielded cables.

[0005] To achieve this objective, the technical solution proposed by the present invention is as follows:

[0006] A non-contact AC detection method, comprising the following steps:

[0007] Construct a confined and shielded protection space against interference electromagnetic, with a sensing hole allowing electromagnetic signals in a specific direction to enter that space. A coil induction is installed in this space to pick up electromagnetic signals passing through the detection hole.

[0008] When detecting a single wire, bring the detection hole close without touching the wire, so that the electromagnetic signal generated by the alternating current passing through the wire passes through the detection hole to enter the shielding space and be picked up by the induction coil, which then provides a corresponding current signal.

[0009] When detecting an untwisted cable composed of two or more wires, bring the detection hole close without touching the cable, then rotate the hole around the cable to successively orient it towards each of the wires, so that the electromagnetic signal generated by the alternating current passing through the target wire passes through the detection hole to enter the protection space and be picked up by the induction coil, which then provides a corresponding current signal.

[0010] When detecting a twisted cable composed of two or more wires, bring the detection hole close without touching the cable, then rotate the hole around the twisted cable and / or move along the longitudinal axis of the cable, so that the electromagnetic signal generated by the alternating current passing through the target wire passes through the detection hole to enter the shielding space and be picked up by the induction coil, which then provides a corresponding current signal.

[0011] Then, the current signals output by the induction coil are amplified and filtered to eliminate noise, and then processed and analyzed by a main MCU chip to obtain the relevant electrical parameters. These electrical parameters include current, voltage, frequency, duty cycle, phase, harmonics and frequency variation signals.

[0012] A non-contact AC detection probe for realizing the non-contact AC detection method, comprising:A shielding metal shell, used for creating a confined space and shielded against electromagnetic interference;A detection port on the shielding metal shell, allowing electromagnetic signals in a specific direction to enter the shielding space;An induction coil located in the shielding metal shell, for detecting electromagnetic signals entering through the detection port and outputting corresponding current signals.

[0013] As a preferred embodiment of the present invention, the induction coil is a hollow induction coil, crossed by an iron rod intended to increase its sensitivity to variations in magnetic field, thus improving the efficiency of detection and making it more sensitive and precise.

[0014] As a preferred embodiment of the present invention, the induction coil is connected to a signal amplification circuit, which amplifies the current signal induced by the coil before inputting it to the main MCU chip for processing and analysis.

[0015] As a preferred embodiment of the present invention, the iron rod is connected to another signal amplification circuit, improving the accuracy and reliability of detection, and enabling adaptation to more complex application scenarios.

[0016] As a preferred embodiment of the present invention, the protective metal shell is connected to a noise filtering circuit, making it possible to filter unwanted noise.

[0017] A non-contact AC detection probe applied to measuring styli, the induction coil being a hollow induction coil, and the probe of the measuring stylus passing through the induction coil, enabling detection of multiple functions with a compact volume and a wide range of applications.

[0018] A non-contact AC detection probe applied to measuring instruments such as multimeters, current clamps, etc., of various shapes and types.

[0019] The advantages of the present invention are as follows: The non-contact AC detection probe of the present invention is designed ingeniously and reasonably. It can directly measure the alternating current on a cable composed of one 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, allowing the electromagnetic signal generated by the target wire to pass through the detection port to enter the shielding space and be picked up by the induction coil. The electromagnetic signals generated by other non-target wires are blocked by the shielding metal shell to avoid interference.This allows the measurement of relevant AC electrical parameters, including current, voltage, frequency, duty cycle, phase, harmonics, and frequency variation signals, without having to strip or separate the cable wires, thus ensuring safe use. In addition, the overall structure is simple and compact, eliminating the need for traditional silicon steel structures, and can operate for long periods without accuracy problems due to heating. The measurement accuracy is high, making the probe suitable for measuring stylus pens, multimeters, clamp meters, and other measuring instruments, with broad application prospects.

[0020] The present invention is explained in more detail with reference to the figures and exemplary embodiments. Description of Figures

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

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

[0023] [Fig.3]: Schematic diagram of the principle circuit of the non-contact AC 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 exploded structure of the non-contact AC detection probe according to embodiment 2 of the present invention.

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

[0035] [Fig. 15]: Diagram of the front structure of the non-contact AC detection probe according to embodiment 3 of the present invention.

[0036] [Fig. 16]: Diagram of the exploded structure of the non-contact AC detection probe according to embodiment 3 of the present invention.

[0037] [Fig. 17]: Schematic diagram of the principle circuit of the non-contact AC detection probe according to embodiment 3 of the present invention.

[0038] [Fig. 18]: Diagram of the three-dimensional structure of the non-contact AC detection probe according to embodiment 4 of the present invention.

[0039] [Fig. 19]: Diagram of the exploded structure of the non-contact AC detection probe according to embodiment 4 of the present invention.

[0040] [Fig.20]: Schematic diagram of the principle circuit of the non-contact AC detection probe according to embodiment 4 of the present invention.

[0041] [Fig.21]: Schematic diagram of the principle circuit of the non-contact AC detection probe according to embodiment 5 of the present invention.

[0042] [Fig.22]: Diagram of the structure of the product according to application example 1 of the present invention.

[0043] [Fig.23]: Diagram of the structure of the product according to application example 2 of the present invention.

[0044] [Fig.24]: Diagram of the structure of the product according to application example 3 of the present invention.

[0045] [Fig.25]: Diagram of the structure of the product according to application example 4 of the present invention.

[0046] [Fig.26]: Diagram of the structure of the product according to application example 5 of the present invention.

[0047] [Fig.27]: Diagram of the structure of the product according to application example 6 of the present invention.

[0048] [Fig.28]: Diagram of the structure of the product according to application example 7 of the present invention.

[0049] [Fig.29]: Diagram of the structure of the product according to application example 8 of the present invention. Specific embodiments

[0050] Embodiment example 1: Refer to Figures 1, 2 and 3. The present invention provides a non-contact AC detection probe 10, comprising a protective metal shell 1 and an induction coil 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 position of the detection port 3 is not limited. The induction coil 2 is placed inside the protective metal shell 1 and faces the detection port 3, to detect the electromagnetic signals entering from the detection port 3. The two ends of the induction coil 2 form the terminals COI and CO2, and the protective metal shell 1 is provided with a terminal NO.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.

[0051] The detection method of the non-contact AC detection probe 10 is as follows: during detection, a confined space shielded against electromagnetic interference is created by the protective metal shell 1. The detection hole 3, located on the protective metal shell 1, allows electromagnetic signals in a specific direction to enter the shielding space, while blocking electromagnetic signals from other directions. The width of the detection hole 3 is preferably 2 mm, and its length is preferably between 2 and 5 mm. The induction coil 2 is fixed inside the protective metal shell 1.

[0052] 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 port 3 is brought close to the single wire without touching it, thereby allowing the electromagnetic signal generated by the alternating current passing through the single wire 6 to pass through the detection port 3 to enter the protective space and be picked up by the induction coil 2, which then outputs a corresponding current signal.

[0053] 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 alternating 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 induction coil 2, which then emits a corresponding current signal.

[0054] When detecting a twisted cable 8 composed of two wires, refer to FIGS. 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 up and down. When the detection hole 3 is aligned with the two wires and oriented to the position corresponding to a specific angle or position, the electromagnetic signal generated by the alternating current passing 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 induction coil 2, which then outputs a corresponding current signal.

[0055] 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 alternating current passing through the target wire of the twisted cable passes through the detection hole 3 to enter the shielding space and be picked up by the induction coil 2, which then outputs a corresponding current signal.

[0056] Refer to [Fig.12]. The main MCU chip may be of the STM8L151 model or the ML54 / 56 series, preferably with a signal amplification circuit and a noise filtering circuit, allowing to amplify and filter the current signals emitted by the induction coil 2.

[0057] The MCU main chip is connected to the non-contact AC detection probe 10 via the terminals COI, CO2 and NO. Through the processing and analysis of the MCU main chip, relevant electrical parameters such as current, voltage, frequency, duty cycle, phase, harmonics and frequency variation signals are obtained.

[0058] Current: When the current flows through the wire, it generates a corresponding magnetic field, captured by the induction coil 2. The principle of electromagnetic induction makes it possible to detect the intensity of the current, and thus to measure its value.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] Frequency variation signals: The variations in the magnetic field, captured by the induction coil 2, make it possible to detect the frequency variation signals.

[0065] Example embodiment 2: Refer to Figures 13 and 14. This example embodiment provides a non-contact AC detection probe, the structure of which is essentially similar to that of example embodiment 1. The difference lies in the fact that the induction coil 2 is a hollow induction coil with an iron rod 4 inserted in the center. The iron rod 4 increases the sensitivity of the induction coil 2 to changes in the magnetic field, thereby improving the detection efficiency and making it more sensitive and accurate.

[0066] Embodiment example 3: Refer to Figures 15, 16 and 17. The present embodiment provides a non-contact AC detection probe, the structure of which is essentially similar to that of Embodiment example 2. The difference lies in the fact that the iron rod 4 is provided with a connection terminal VO extending out of the protective metal shell 1, used for detecting current, voltage, frequency, duty cycle, phase, harmonics and frequency variation signals, thereby increasing the detection accuracy.

[0067] Embodiment example 4: Refer to Figures 18, 19 and 20. The present embodiment provides a non-contact AC detection probe, the structure of which is essentially similar to that of embodiment example 3. The difference lies in the fact that the iron rod 4 is replaced by a measuring probe 5, with a VO connection terminal. For example, the measuring probe can be that of a multimeter, thus increasing the functions of the multimeter. The protective metal shell 1 is connected to a noise filtering circuit to eliminate unwanted noise. The induction coil 2 is connected to a signal amplification circuit, which amplifies the current signals induced by the coil and transmits them to the main chip MCU for processing and analysis.

[0068] Embodiment example 5: Refer to [Fig.21]. The present embodiment proposes a non-contact AC detection probe, the structure of which is essentially similar to that of embodiment example 3. The difference lies in that the protective metal shell 1 is connected to a noise filtering circuit to eliminate unwanted noise. The induction coil 2 is connected to a signal amplification circuit, which amplifies the current signals induced by the coil and transmits them to the MCU main chip for processing and analysis. The iron rod 4 is connected to another signal amplification circuit, which further improves the sensitivity to magnetic field changes, increasing the detection accuracy and reliability, and making it possible to adapt to more complex application scenarios.

[0069] A non-contact AC sensing probe according to the present invention can be used with measuring probes or measuring instruments, as illustrated in the following application examples.

[0070] Application Example 1: Refer to [Fig.22]. The non-contact AC detection probe 10 proposed in the embodiment example 1 can be used with a multi-function detection clamp. The non-contact AC detection probe 10 is located inside the arc-shaped concave portion of the multi-function detection clamp.

[0071] Application Example 2: Refer to [Fig.23]. The non-contact AC sensing probe 10 provided in embodiments 1 or 2 can be used with a dual-sensing ammeter. The non-contact AC sensing probe 10 is located inside the arc-shaped concave portion of the sensing head of the dual-sensing ammeter.

[0072] Application example 3: Refer to [Fig.24]. The non-contact AC detection probe 10 proposed in embodiment example 2 can be used in a non-contact current clamp. The non-contact current clamp is provided with a protruding portion at the location of the jaws, where the non-contact AC detection probe 10 is located. During detection, it is sufficient to bring the protruding portion close to the electrical cable to be tested.

[0073] Application Example 4: Refer to [Fig.25]. The non-contact AC detection probe 10 proposed in the embodiment example 3 can be used in an electrical tester. The electrical tester is equipped with a fixed test probe, and the non-contact AC 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.

[0074] Application example 5: Refer to [Fig.26]. The non-contact AC detection probe 10 proposed in embodiment example 4 can be used at the probe end of a multimeter. When detecting, it is sufficient to bring the probe end of the multimeter close to the electrical cable to be tested.

[0075] Application example 6: Refer to [Fig.27]. The non-contact AC detection probe 10 proposed in embodiment example 4 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.

[0076] Application Example 7: Refer to [Fig.28]. The non-contact AC detection probe 10 proposed in embodiment example 5 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.

[0077] Application example 8: Refer to [Fig.29]. The non-contact AC detection probe 10 proposed in embodiment example 5 can be used at the detection position at the head of a multifunction energy meter. When detecting, it is sufficient to place the electric cable to be tested in the detection position at the head of the multifunction energy meter.

[0078] 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.

[0079] Measuring instruments using the non-contact AC sensing probe 10 of the present invention can perform AC 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. AC measurement: It can measure the alternating current on a single wire or a cable containing multiple wires (except shielded cables), and can detect not only current, but also AC voltage, frequency, duty cycle, phase, harmonics and frequency variation signals. 2. Single-phase measurement: In addition to measuring single-phase current and voltage, it can calculate electric power and display the result through the processing of the MCU main chip. 3. Three-phase measurement: It can detect AC voltage, frequency, duty cycle, phase, harmonics and frequency variation signals on three-phase four-wire cable (except shielded cable) and display the measurement results. 4. Simplified structure: It eliminates the traditional silicon steel structure, allowing prolonged operation without precision problems due to heating. 5. Wireless Connectivity: 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.

[0080] Modifications and Variations: Based on 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, the structures and methods obtained by following the same or similar steps to the examples embodiments described above also fall within the scope of protection of the present invention.

Claims

Claims

1. A non-contact AC detection method, characterized by the following steps: Constructing a confined and electromagnetically shielded shielding space with a detection hole allowing electromagnetic signals in a specific direction to enter this space. An induction coil is installed in this space to pick up electromagnetic signals passing through the detection hole. To detect a single wire, bring the detection hole close without touching the single wire so that the electromagnetic signal generated by the alternating current passing through the wire passes through the detection hole to enter the shielding space and is picked up by the induction coil, which then outputs a corresponding current signal.To detect an untwisted cable consisting of two or more wires, bring the detection hole close without touching the cable, 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 alternating current passing through the target wire passes through the detection hole to enter the shielding space and be picked up by the induction coil, which then provides a corresponding current signal.To detect 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 twisted cable so that the electromagnetic signal generated by the alternating current flowing in the target wire passes through the detection hole to enter the shielding gap and be picked up by the induction coil, which then provides a corresponding current signal.

2. According to the non-contact AC detection method according to claim 1, characterized in that: after amplification and filtering of the output current signals of the induction coil, the relevant electrical parameters are obtained by processing and analyzing via the main chip MCU.

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

4. A non-contact AC detection probe for carrying out the non-contact AC detection method according to any one of claims 1 to 3, characterized in that it comprises: A protective metal shell, for constructing a shielding space confined and shielded against electromagnetic interference; the protective metal shell being equipped with a detection port allowing electromagnetic signals in a specific direction to enter the shielding space; An induction coil, arranged in the shielding space, for detecting electromagnetic signals entering the protective metal shell through the detection port, and outputting corresponding current signals.

5. According to the non-contact AC detection probe according to claim 4, characterized in that: the induction coil is a hollow induction coil, crossed by an iron rod intended to increase its sensitivity to variations in magnetic field.

6. According to the non-contact AC detection probe according to claim 4, characterized in that: the induction coil is connected to a signal amplification circuit.

7. According to the non-contact AC detection probe according to claim 5, characterized in that: the iron rod is connected to another signal amplification circuit.

8. According to the non-contact AC detection probe according to claim 5, characterized in that: the protective metal shell is connected to a noise filtering circuit.

9. A non-contact AC detection probe according to claim 4, applied to measuring styli, characterized in that: the induction coil is a hollow induction coil, and the probe of the measuring stylus passes through the induction coil.

10. A non-contact AC sensing probe according to any one of claims 4 to 8, applied to measuring instruments.

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