CN220671518U - Non-contact alternating current sensing probe, meter pen using same and measuring instrument - Google Patents

Abstract

The utility model discloses a non-contact alternating current sensing probe, a meter pen and a measuring instrument using the same. During measurement, alternating current measurement can be directly carried out on a single wire or a cable formed by two or more wires, only electromagnetic signals generated by target wires can enter through a detection port, electromagnetic signals generated by other non-target wires are shielded by a metal shielding shell, interference is avoided, sensing of alternating current related electrical parameters including current, voltage, frequency, duty ratio, phase, harmonic wave, variable frequency signal inlet and the like is realized, and sensing can be carried out without peeling and branching the cable, so that the operation is simple and convenient; in addition, the traditional silicon steel sheet structure is omitted, the device can work for a long time, the problem of inaccurate precision caused by heat cannot be solved, the device can be applied to measuring instruments such as a meter pen, a universal meter and a clamp meter, and the device has a large application prospect.

Description

Non-contact alternating current sensing probe, meter pen using same and measuring instrument

Technical Field

The utility model relates to the technical field of measuring instruments, in particular to a non-contact alternating current sensing probe, a meter pen applying the same and a measuring instrument.

Background

In order to protect the electricity safety, the wires which are possibly exposed are protected by an insulating adhesive layer or a plastic shell; in this case, when the conventional contact measurement is adopted, the contact measurement is performed after the insulation layer is broken, or the contact is performed in the power line after the insulation layer is penetrated, no matter the broken measurement or the penetration measurement is used, the insulation layer of the protected power system can be damaged, so that the potential safety hazard of electricity can be caused.

For this reason, non-contact measuring instruments are commercially available, which can measure alternating current without damaging the protective insulation of the wire. However, most of the existing non-contact induction current measuring instruments on the market use conventional probes with thick silicon steel sheets in a closed loop or semi-open mode, which can realize the purpose of alternating current measurement on wires, but can only perform alternating current measurement on a single wire, and when a cable (except a shielding cable) consists of two or more wires, direct alternating current measurement cannot be performed, because when a clamp meter clamps two wires (such as a live wire and a zero wire) at the same time, magnetic fields generated by the two wires are counteracted in opposite directions, namely, a composite magnetic field is zero, the indication number of the clamp meter is zero, and the real current of the circuit cannot be reflected. For this reason, it is necessary to peel off the insulating protective layer of the cable and separately measure each wire, which is not only troublesome to operate and low in measurement efficiency, but also has a problem of damaging the insulating protective layer, affecting the safety in use.

Disclosure of Invention

The utility model aims to overcome the defects, and provides a non-contact alternating current sensing probe which is reasonable in structural design and can directly perform alternating current measurement on a non-shielding cable, and a meter pen and a measuring instrument applying the probe.

In order to achieve the above purpose, the technical scheme provided by the utility model is as follows:

the non-contact alternating current sensing probe comprises a metal shielding shell and an induction coil, wherein the metal shielding shell is used for constructing a closed shielding space for preventing electromagnetic interference; the metal shielding shell is provided with a detection port which can allow electromagnetic signals in a specific direction to enter the shielding space; the induction coil is arranged in the metal shielding shell, and is used for sensing electromagnetic signals entering the metal shielding shell from the detection port and outputting corresponding current signals.

As a preferable scheme of the utility model, the induction coil is an air core induction coil, and an iron rod for enhancing the sensitivity of the induction coil to magnetic field change is inserted in the middle of the induction coil, and can enhance the sensitivity of the induction coil to magnetic field change, so that the detection effect is improved, and the induction coil is more sensitive and accurate.

As a preferable scheme of the utility model, the induction coil is connected with the signal amplifying circuit, and the signal amplifying circuit amplifies the current signal induced by the induction coil and inputs the amplified current signal to the main control MCU chip for analysis and operation.

As a preferable scheme of the utility model, the iron rod is connected with another signal amplifying circuit, so that the accuracy and reliability of detection can be improved, and the method is suitable for more complex application scenes.

As a preferred embodiment of the present utility model, the metal shielding case is connected to a noise filter circuit, so that unnecessary noise can be filtered.

The utility model provides a table pen, includes non-contact AC sensing probe, the induction coil in the non-contact AC sensing probe is hollow induction coil, the probe of table pen passes induction coil realizes more functional detection, small in size moreover, application scope is wide.

A measuring instrument comprising the non-contact ac sensing probe may be a multimeter, a clamp meter, or the like of different shapes and types.

The beneficial effects of the utility model are as follows: the non-contact alternating current sensing probe has ingenious and reasonable structural design, can directly perform alternating current measurement on a single electric wire or a cable (except a shielding cable) formed by two or more electric wires, and enables a detection port to be adjusted to a better measurement position of a target electric wire through rotation and/or movement during detection so as to enable the target electric wire to generate electromagnetic signals to pass through the detection port and enter a shielding space to be collected by an induction coil; the electromagnetic signals generated by other non-target wires are shielded by the metal shielding shell, so that interference is avoided, the alternating current related electrical parameters including current, voltage, frequency, duty ratio, phase, harmonic wave, variable frequency signals and the like are obtained by sensing, the sensing can be performed without peeling and branching the cable, the use safety is ensured, and the operation is simple and convenient; in addition, the whole structure is simple, the volume is small, the traditional silicon steel sheet structure is omitted, the device can work for a long time, the problem of inaccurate precision caused by heat cannot be generated, the measurement precision is high, the device can be suitable for measuring instruments such as a meter pen, a universal meter, a clamp meter and the like, and the device has a large application prospect.

The utility model will be further described with reference to the drawings and examples.

Drawings

Fig. 1 is a schematic perspective view of a non-contact ac sensing probe according to embodiment 1 of the present utility model.

Fig. 2 is an exploded view of a noncontact ac sensing probe according to embodiment 1 of the present utility model.

Fig. 3 is a schematic circuit diagram of a noncontact ac sensing probe according to embodiment 1 of the present utility model.

Fig. 4 is a schematic view 1 of a structure of a probe for sensing a single wire in embodiment 1 of the present utility model.

Fig. 5 is a schematic view 2 of the structure of the probe for sensing a single wire in embodiment 1 of the present utility model.

Fig. 6 is a schematic view 1 of the structure of a probe-sensing non-twisted cable in embodiment 1 of the present utility model.

Fig. 7 is a schematic view 2 of the structure of the probe sensing non-twisted cable in embodiment 1 of the present utility model.

Fig. 8 is a schematic view 1 of a probe sensing twisted cable in embodiment 1 of the present utility model.

Fig. 9 is a schematic view 2 of the structure of the probe sensing twisted cable in embodiment 1 of the present utility model.

Fig. 10 is a schematic view 1 of a probe for sensing another twisted cable in embodiment 1 of the present utility model.

Fig. 11 is a schematic view of a structure of a probe for sensing another twisted cable in embodiment 1 of the present utility model.

Fig. 12 is a schematic diagram of a connection port of a master MCU chip in embodiment 1 of the present utility model.

Fig. 13 is an exploded view of a noncontact ac sensing probe according to embodiment 2 of the present utility model.

Fig. 14 is a schematic circuit diagram of a noncontact ac sensing probe according to embodiment 2 of the present utility model.

Fig. 15 is a schematic diagram showing the front view of the non-contact ac sensing probe according to embodiment 3 of the present utility model.

Fig. 16 is an exploded view of a noncontact ac sensing probe according to embodiment 3 of the present utility model.

Fig. 17 is a schematic circuit diagram of a noncontact ac sensing probe according to embodiment 3 of the present utility model.

Fig. 18 is a schematic perspective view of a non-contact ac sensing probe according to embodiment 4 of the present utility model.

Fig. 19 is an exploded view of a noncontact ac sensing probe according to embodiment 4 of the present utility model.

Fig. 20 is a schematic circuit diagram of a noncontact ac sensing probe according to embodiment 4 of the present utility model.

FIG. 21 is a schematic circuit diagram of a noncontact AC sensing probe according to embodiment 5 of the present utility model.

Fig. 22 is a schematic diagram of the structure of the product of application example 1 of the present utility model.

Fig. 23 is a schematic diagram of the structure of the product of application example 2 of the present utility model.

FIG. 24 is a schematic view showing the structure of a product according to application example 3 of the present utility model.

Fig. 25 is a schematic diagram of the structure of the product of application example 4 of the present utility model.

FIG. 26 is a schematic diagram showing the structure of a product according to application example 5 of the present utility model.

FIG. 27 is a schematic view showing the structure of a product according to application example 6 of the present utility model.

Fig. 28 is a schematic diagram of the structure of the product of application example 7 of the present utility model.

Fig. 29 is a schematic view of the structure of the product of application example 8 of the present utility model.

Detailed Description

Example 1: referring to fig. 1, 2 and 3, the non-contact ac sensing probe 10 provided in this embodiment includes a metal shielding shell 1 and an induction coil 2, wherein the metal shielding shell 1 is used for constructing a closed shielding space for preventing electromagnetic interference; the metal shielding shell 1 is provided with a detection port 3 which can allow electromagnetic signals in a specific direction to enter a shielding space; the induction coil 2 is arranged in the metal shielding shell 1 and is opposite to the position of the detection port 3, and is used for detecting electromagnetic signals entering the metal shielding shell 1 from the detection port 3. Terminals CO1 and CO2 are formed at two ends of the induction coil 2, and a terminal NO is arranged on the metal shielding shell 1. In this embodiment, the metal shielding shell 1 is a square shell, and in other embodiments, the metal shielding shell 1 may also be in a cylindrical shape.

The sensing method of the non-contact ac sensing probe 10 is as follows, when sensing, a closed shielding space for preventing electromagnetic interference is constructed by the metal shielding shell 1, and as the metal shielding shell 1 is provided with the detection port 3, electromagnetic signals in a specific direction can enter the detection port 3 in the shielding space, and electromagnetic signals in other directions can be shielded. The width of the detection port 3 is preferably 2mm, and the length is preferably 2-5mm. The induction coil 2 is fixed in the metal shield 1.

When sensing a single wire 6, see fig. 4 and 5, the single wire 6 comprises a wire core 61 and an insulating protective layer 62 covering the wire core 61. The detection port 3 is close to but not contacted with the single wire, so that an electromagnetic signal generated when the single wire 6 passes through alternating current passes through the detection port 3 and enters a shielding space to be collected by the induction coil 2, and a corresponding current signal is output by the induction coil 2;

when sensing that two wires are arranged in parallel to form a non-twisted cable 7, referring to fig. 6 and 7, the detection port 3 is close to but not in contact with the non-twisted cable 7, and then rotates around the non-twisted cable 7, so that the detection port 3 faces the wires in the non-twisted cable 7 one by one, that is, when the detection port 3 is horizontally arranged with the two wires, and when the detection port 3 faces the left wire or the right wire, an electromagnetic signal generated when the left target wire or the right target wire passes through alternating current passes through the detection port 3, enters a shielding space to be collected by the induction coil 2, and a corresponding current signal is output by the induction coil 2;

when a stranded cable 8 is formed by stranding two wires, referring to fig. 8 and 9, the detection port 3 is close to but not in contact with the stranded cable 8, and then rotates leftwards or rightwards (clockwise or anticlockwise) around the stranded cable 8 or moves upwards or downwards, when rotating to a corresponding angle or moving to a corresponding position to enable the detection port 3 to be approximately level with the two wires, an electromagnetic signal generated when a target wire close to one side of the detection port 3 passes through alternating current and enters a shielding space through the detection port 3 to be collected by the induction coil 2, and a corresponding current signal is output by the induction coil 2.

When sensing that more than five wires are twisted to form a twisted cable, referring to fig. 10 and 11, the detection port 3 is close to but not in contact with the twisted cable, and then rotates leftwards or rightwards around the twisted cable and moves upwards or downwards along the central axis direction of the twisted cable, so that the detection port 3 finds a preferred measuring position which can be opposite to the target wire in the movement adjustment process, and because the sensing value is increased to the highest value when the detection port is positive, an electromagnetic signal generated when the target wire in the twisted cable passes through alternating current passes through the detection port 3, enters the shielding space to be collected by the induction coil 2, and the induction coil 2 outputs a corresponding current signal.

Referring to fig. 12, the master control MCU chip may select an MCU chip with a model of STM8L151 or ML54/56 series, and is preferably matched with a signal amplifying circuit and a noise filtering circuit, so as to amplify and filter the current signal output by the induction coil 2.

The main control MCU chip is connected with the non-contact alternating current sensing probe 10 through a wiring terminal CO1, a wiring terminal CO2 and a wiring terminal NO. And obtaining relevant electrical parameters such as current, voltage, frequency, duty ratio, phase, harmonic wave, variable frequency signal and the like through analysis and operation processing of the main control MCU chip.

Current flow: when current passes through the electric wire, a corresponding magnetic field is generated, the magnetic field can be captured and collected by the induction coil 2, the intensity of the current is detected by utilizing the electromagnetic induction principle, and the magnitude of the current is measured.

Voltage: the electromagnetic field change can be detected by utilizing the electromagnetic induction principle so as to obtain voltage information, and the voltage is measured.

Frequency: in an ac circuit, the periodic variations of current and voltage correspond to a particular frequency, and by analyzing the period and frequency of the electromagnetic signal, the frequency of the wire transmission can be determined.

Duty cycle: the duty ratio refers to a proportional relationship between the duration of a high level and the period in one period signal. The duty cycle of the signal can be analyzed and measured by detecting a change in the pulse width or signal strength of the electromagnetic signal.

Phase: the phase in the electromagnetic signal may be measured by detecting the time difference between the start of the signal and the start of the reference signal. This is based on the phase describing the offset relationship of the periodic signal over time, with the velocity and time delay of electromagnetic wave propagation being used to determine the phase information.

Harmonic wave: by analyzing the spectrum of the electromagnetic signal, harmonic components in the wire can be detected. Harmonics refer to periodic signal components having frequencies that are integer multiples of the fundamental frequency. Nonlinear loads can cause distortion in current or voltage, thereby creating harmonics, the presence and magnitude of which can be determined by detecting and analyzing the frequency spectrum of the electromagnetic signal.

Variable frequency signal: the variable frequency signal is detected by the change in magnetic field generated by the induction coil 2 inducing the wire current.

Example 2: referring to fig. 13 and 14, the structure of the non-contact ac sensing probe provided in this embodiment is basically the same as that of embodiment 1, except that the induction coil 2 is an air core induction coil, and an iron rod 4 is inserted between the air core induction coil and the air core induction coil. The iron rod 4 can enhance the sensitivity of the induction coil 2 to magnetic field change, and improve the detection effect, so that the induction coil is more sensitive and accurate.

Example 3: referring to fig. 15, 16 and 17, the structure of the non-contact ac sensing probe provided in this embodiment is basically the same as that of embodiment 2, and the difference is that the iron rod 4 is provided with a terminal VO extending out of the metal shielding case 1, so as to induce current, voltage, frequency, duty cycle, phase, harmonic wave, variable frequency signal, etc., and improve the detection accuracy.

Example 4: referring to fig. 18, 19 and 20, the non-contact ac sensing probe according to the present embodiment has a structure substantially identical to that of embodiment 3, except that a stylus 5 is used instead of the iron bar 4 and has a terminal VO, and the stylus may be a multimeter stylus, for example, so that the function of the multimeter can be further increased. The metal shield 1 is connected to a noise filter circuit, and can filter unnecessary noise. The induction coil 2 is connected with a signal amplifying circuit, and the signal amplifying circuit amplifies the current signal induced by the induction coil 2 and inputs the current signal to a main control MCU chip for analysis and operation.

Example 5: referring to fig. 21, the non-contact ac sensing probe according to this embodiment is basically identical to that of embodiment 3, except that the metal shielding case 1 is connected to a noise filtering circuit, so as to filter unnecessary noise. The induction coil 2 is connected with a signal amplifying circuit, and the signal amplifying circuit amplifies the current signal induced by the induction coil 2 and inputs the current signal to a main control MCU chip for analysis and operation. The iron rod 4 is connected with another signal amplifying circuit, so that the sensing capability of magnetic field change can be further enhanced, the accuracy and reliability of detection are improved, and the iron rod is suitable for more complex application scenes.

The non-contact alternating current sensing probe can be applied to a stylus, a measuring instrument and the like, and can be concretely seen in the following application examples.

Application example 1: referring to fig. 22, a non-contact ac sensing probe 10 provided in embodiment 1 can be applied to a multifunctional induction clamp, where the non-contact ac sensing probe 10 is located at an inner side of an arc recess of a clamp of the multifunctional induction clamp.

Application example 2: referring to fig. 23, a non-contact ac sensing probe 10 provided in embodiment 1 or 2 can be applied to a dual sensing ammeter, and the non-contact ac sensing probe 10 is located at an inner side position of an arc recess of a detection head of the dual sensing ammeter.

Application example 3: referring to fig. 24, a non-contact ac sensing probe 10 provided in embodiment 2 can be applied to a non-contact clamp meter, in which a protrusion is provided at a clamp mouth position of the non-contact clamp meter, and the non-contact ac sensing probe 10 is located in the protrusion. During detection, the protruding part is close to the wire and cable to be detected.

Application example 4: referring to fig. 25, embodiment 3 provides a non-contact ac sensing probe 10 that can be applied to an electrical tester having a stationary test pen, where the non-contact ac sensing probe 10 is located inside the body of the stationary test pen. During detection, the pen body of the fixed test pen is close to the wire and cable to be detected.

Application example 5: referring to fig. 26, the non-contact ac sensing probe 10 provided in embodiment 4 can be applied to the position of the head of a stylus of a multimeter, and the head of the stylus is close to the wire and cable to be detected during detection.

Application example 6: referring to fig. 27, the non-contact ac sensing probe 10 provided in embodiment 4 can be applied to the head position of a multifunctional meter rod, and the head of the multifunctional meter rod is close to a wire or cable to be detected during detection.

Application example 7: referring to fig. 28, the non-contact ac sensing probe 10 provided in embodiment 5 can be applied to a head detection position for pen-type current measurement, and when detecting, a wire and cable to be detected can be put into the head detection position for pen-type current measurement.

Application example 8: referring to fig. 29, the non-contact ac sensing probe 10 provided in embodiment 5 can be applied to the head detection position of a multifunctional electric energy meter, and when in detection, a wire and cable to be detected can be put into the head detection position of the multifunctional electric energy meter.

The above embodiments and application examples are only preferred embodiments and application modes of the present utility model, and the present utility model cannot be listed in one-to-one, and all the technical solutions adopting one of the above embodiments or application modes, or the equivalent changes made according to the above embodiments, are within the scope of the present utility model.

The measuring instrument adopting the non-contact alternating current sensing probe 10 of the utility model can directly carry out alternating current measurement on a single electric wire or a cable (except a shielding cable) formed by two or more electric wires so as to obtain electric parameters such as current, voltage, frequency, duty ratio, phase, harmonic wave, variable frequency signal and the like. In general, the utility model has the following advantages:

1. ac measurements may be made on a single wire or on a cable containing multiple wires (in addition to the shielded wires), and ac voltages, frequencies, duty cycles, phases, harmonics, and variable frequency signals may be sensed in addition to current.

2. Besides measuring single-phase alternating current and voltage, the electric power can be calculated and the result can be displayed through the operation processing of the main control MCU chip.

3. Ac voltages, frequencies, duty cycles, phases, harmonics and variable frequency signals can be sensed and measurement data results displayed on ac three-phase four-wire cables (except shielded cables).

4. The traditional silicon steel sheet structure is omitted, the long-time work can be realized, and the problem of inaccurate precision caused by heat can be avoided.

5. The main control MCU chip can share data with the smart phone, the tablet personal computer and the computer by utilizing wireless connection modes such as Bluetooth, wi-Fi and the like, and is simple and convenient to operate.

Variations and modifications to the above would be obvious to persons skilled in the art to which the utility model pertains from the foregoing description and teachings. Therefore, the utility model is not limited to the specific embodiments disclosed and described above, but some modifications and changes of the utility model should be also included in the scope of the claims of the utility model. In addition, although specific terms are used in the present specification, these terms are for convenience of description only and do not limit the present utility model in any way. Other products obtained by adopting the same or similar structures as those described in the above embodiments of the present utility model are within the scope of the present utility model.

Claims (7)

1. A non-contact ac sensing probe, comprising

The metal shielding shell is used for constructing a closed shielding space for preventing electromagnetic interference; the metal shielding shell is provided with a detection port which can allow electromagnetic signals in a specific direction to enter the shielding space;

and the induction coil is arranged in the shielding space and is used for sensing electromagnetic signals entering the metal shielding shell from the detection port and outputting corresponding current signals.

2. The non-contact ac sensing probe of claim 1, wherein: the induction coil is an air core induction coil, and an iron rod for enhancing the sensitivity of the induction coil to magnetic field change is inserted in the middle of the induction coil.

3. The non-contact ac sensing probe of claim 2, wherein: the induction coil is connected with the signal amplifying circuit.

4. The non-contact ac sensing probe of claim 2, wherein: the iron rod is connected with another signal amplifying circuit.

5. The non-contact ac sensing probe of any of claims 1-4, wherein: the metal shielding shell is connected with the noise filtering circuit.

6. A stylus comprising the non-contact ac sensing probe of claim 1, the stylus probe passing through the induction coil.

7. A measuring instrument comprising a non-contact ac sensing probe according to any one of claims 1 to 5.