Electronic measuring instrument

Abstract

The utility model discloses an electronic measuring instrument which comprises an electricity meter and a meter pen box, the electricity meter is provided with a first hole site, a second hole site, a third hole site, a fourth hole site and a logic circuit, and the meter pen box comprises a circuit board; one end of the meter pen box is provided with a first terminal, a second terminal, a third terminal and a fourth terminal, the other end of the meter pen box is provided with a pair of test probes, the first to fourth terminals are respectively and correspondingly inserted into the first to fourth hole sites, and the circuit board is coupled to the third and fourth terminals and the pair of test probes; the first terminal and the second terminal respectively comprise a metal elastic sheet, when the first terminal and the second terminal are respectively inserted into the first hole position and the second hole position, a loop is formed between the first hole position and the second hole position through the meter pen box, and whether the meter pen box is inserted into the electric meter or not is judged through the logic circuit. The meter pen box terminal is simple in structure, high in measuring efficiency and suitable for measuring conventional current and 30A large current, unexpected damage of an electric meter is avoided, meanwhile, the embedded copper insert is positioned and fastened, and the contact matching reliability of the meter pen box terminal and an electric meter hole site is improved.

Description

Technical Field

[0001] This utility model relates to an electronic measuring instrument, specifically an electronic measuring instrument for measuring large currents. Background Technology

[0002] A multimeter or clip-on meter is a versatile electronic measuring instrument that typically includes an ammeter, voltmeter, and ohmmeter. It has a variety of different measuring functions and is also known as a multimeter, multi-meter, or multi-purpose electricity meter.

[0003] First, please refer to Figure 1 , Figure 1 This is a schematic diagram of the appearance of a well-known multimeter. The main body 110 of the multimeter has four holes 111, 112, 113, and 114. One end of the test probe 120, terminal 121, is inserted into hole 111, and the other test probe is inserted into another hole (not shown). When using the multimeter, one test probe is held in each hand to measure the object being measured. Please refer to... Figure 2 , Figure 2 This is a partially enlarged cross-sectional view of a well-known multimeter and test probe assembly. When the terminal 121 of the test probe 120 is inserted into the hole 111, a complete electrical connection is formed between the terminal 121 and the interior of the hole 111.

[0004] However, since the terminals of the multimeter are standard components, they can be used with any universal test probe during general measurements. Therefore, when users use universal test probes to measure high currents (such as 30A), due to the design of high current measurement inside the product and the space limitations of the handheld product itself, it is difficult to effectively reduce the resistance of the circuit through which the current flows. The heat generated cannot be effectively dissipated, which will cause the plastic of the product to deform, resulting in unpredictable harm or damage. The above defects need to be improved. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide an electronic measuring instrument that overcomes the defects of existing electronic measuring instruments in that the heating and deformation when measuring large currents can lead to damage to the measuring instrument or even other unpredictable accidents.

[0006] The technical solution adopted by this utility model to solve its technical problem is as follows: An electronic measuring instrument is constructed, comprising: an electricity meter having a first hole, a second hole, a third hole, a fourth hole, and a logic circuit; and a test lead box, the test lead box including a circuit board. One end of the test lead box has a first terminal, a second terminal, a third terminal, and a fourth terminal, and the other end of the test lead box has a pair of test probes. The first to fourth terminals are respectively inserted into the first to fourth holes. The circuit board is coupled to the third and fourth terminals and the pair of test probes. Each of the first and second terminals includes a metal spring. When the first and second terminals are respectively inserted into the first and second holes, a circuit is formed between the first and second holes through the test lead box, thereby allowing the logic circuit to determine whether the electricity meter has the test lead box inserted.

[0007] In one embodiment of the present invention, the aforementioned third and fourth apertures are used to obtain measurement signals from the pair of test probes for measuring the test object.

[0008] In one embodiment of this utility model, the aforementioned tester box includes a fuse and a current sampling resistor, which are used to transmit the measurement signal back to the meter.

[0009] In one embodiment of the present invention, the aforementioned first hole and second hole are further provided with embedded copper inserts, and the aforementioned metal springs are respectively disposed on one side of the first terminal and the second terminal. When the first terminal and the second terminal are respectively inserted into the first hole and the second hole, the aforementioned metal springs contact the aforementioned embedded copper inserts.

[0010] In one embodiment of the present invention, the aforementioned electricity meter further includes a microcontroller unit electrically connected to the logic circuit. The microcontroller unit determines the measurement mode entered by the electricity meter based on the relative high and low potentials between the output terminals of the logic circuit.

[0011] In one embodiment of the present invention, the aforementioned electricity meter further includes a user interface, which displays a warning message when it is determined that the measurement mode entered by the electricity meter is an abnormal measurement mode.

[0012] In one embodiment of this utility model, the aforementioned tester box is suitable for high current measurement mode with a maximum measurement current of 30A.

[0013] In one embodiment of this utility model, the aforementioned first hole is a current measurement hole for 10A or less, the second hole is a current measurement hole for 1A or less, the third hole is a grounding terminal, and the fourth hole is a composite measurement hole.

[0014] In one embodiment of this invention, the aforementioned composite measuring aperture can measure voltage, resistance, and capacitance.

[0015] In one embodiment of the present invention, the embedded copper insert includes a protrusion on the wall of the insert from the inside out, the protrusion being fitted into the plastic material of the meter hole.

[0016] Compared with the prior art, the electronic measuring instrument implementing this utility model has the following advantages:

[0017] 1. Simple structure, high measurement efficiency, applicable to measuring conventional current and high current, with a maximum measurement current of 30A; when high current needs to be measured, a high current measuring tester box is used in conjunction with the meter to avoid unpredictable damage.

[0018] 2. A protrusion extending from the inside out is provided on the side wall of the embedded copper insert. This protrusion fits into the plastic material of the meter hole, ensuring that the embedded copper insert is firmly and reliably positioned. This improves the reliability of the contact fit between the meter terminal box terminal and the embedded copper insert in the meter hole. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the appearance of an existing three-way multimeter.

[0020] Figure 2 This is a partially enlarged cross-sectional view of the existing three-way multimeter and test probe combination.

[0021] Figure 3 This is a schematic diagram of the appearance of the electronic measuring instrument of this utility model.

[0022] Figure 4 This is a partially enlarged cross-sectional view of a specific embodiment of the combination of the tester box of the electronic measuring instrument of this utility model and the meter using the tester box.

[0023] Figure 5 This is a side view of the test pen box in the electronic measuring instrument of this utility model. Detailed Implementation

[0024] The present invention will now be described in detail with reference to typical embodiments and accompanying drawings. The same reference numerals in each view indicate the same or similar parts. Although the specification discloses typical embodiments, other embodiments may exist that modify the embodiments described herein without departing from the spirit and scope of the present invention. The following detailed description does not limit the present invention; the scope of protection of the present invention is defined by the claims and their equivalents.

[0025] Explanation of icon numbers in the instruction manual:

[0026] 110: Main body; 111, 112, 113, 114: Hole positions;

[0027] 120: Test probe; 121: Terminal;

[0028] 1: Electricity meter; 11, 12, 13, 14: Hole positions; 15: Knob; 16: Display;

[0029] 2: Test probe box; 21, 22, 23, 24: Terminals; 25, 26: Test probes;

[0030] 251, 261: First end of the test probe; 252, 262: Second end of the test probe;

[0031] 101: Embedded copper insert; 1011: Embedded copper insert protrusion

[0032] 211: Metal shrapnel.

[0033] Please see Figure 3 , Figure 3 This is a schematic diagram of the appearance of the electronic measuring instrument of this utility model. The electronic measuring instrument of this application includes a meter 1 and a test lead box 2. The meter 1 is, for example, a composite digital meter. The meter 1 includes terminals 11, 12, 13 and 14, a knob 15 and a display 16. The knob 15 is used to select the measurement mode (such as current mode, voltage mode, resistance mode, etc.), and the display 16 can display the measurement results according to the measurement mode.

[0034] One end of the tester box 2 is provided with four terminals 21, 22, 23 and 24, which can be respectively inserted into the holes 11, 12, 13 and 14 of the meter 1. In this embodiment, hole 11 is the hole for measuring high current (below 10A), hole 12 is the hole for measuring low current (below 1A), hole 13 is the grounding terminal, and hole 14 is the hole for measuring composite current (voltage / resistance / capacitance).

[0035] The other end of the test probe holder 2 is connected to a pair of test probes, consisting of test probes 25 and 26. The first ends 251 and 261 of test probes 25 and 26 are connected to the test probe holder 2, respectively, while the second ends 252 and 262 of test probes 25 and 26 are used to contact the object under test for measurement. The test probe holder 2 includes a fuse (with a current rating of 30A) and a current sampling resistor (not shown) to transmit the measurement signal back to the meter 1. The apertures 13 and 14 of the meter 1 are used to obtain the measurement signals from the test probes 25 and 26 for measuring the object under test. Test probes 25 and 26 can be needle-type, clip-type, or probe rod-type, etc. In this embodiment, test probes 25 and 26 are alligator clips as an example.

[0036] Please see Figure 4 , Figure 4This is a partially enlarged cross-sectional view showing a specific embodiment of the combination of the meter holder and the meter using the meter holder of this utility model. A metal spring 211 is provided on one side of the terminal 21 of the meter holder 2 (similarly, a metal spring is also provided on one side of the terminal 22). The metal spring 211 is made of, for example, copper or other commonly used conductive materials. The hole 11 is provided with copper embedded parts 101 on opposite sides (similarly, the hole 12 is also provided with copper embedded parts). Figure 5 This is a side view of the test lead box of the electronic measuring instrument of this utility model. In this embodiment, the meter 1 further includes a logic circuit for detecting the current measurement mode, and a microcontroller unit (not shown) electrically connected to the logic circuit. The test lead box 2 further includes a circuit board (not shown), which is coupled to terminals 23 and 24 and test probes 25 and 26. Please refer to the diagram for further details. Figure 4 and Figure 5 When terminal 21 of the test lead box 2 is inserted into hole 11 of meter 1, the metal spring 211 inside terminal 21 contacts the embedded copper insert 101 of hole 11 of meter 1, forming a one-sided conduction. Similarly, the metal spring inside terminal 22 inserted into hole 12 also contacts the embedded copper insert of hole 12, forming a one-sided conduction. Terminals 21 and 22 are directly short-circuited through a metal (not shown). When test lead box 2 is inserted into meter 1, a circuit is formed between holes 11 and 12 through test lead box 2, thereby changing the logic state. Accordingly, the logic circuit of meter 1 determines whether test lead box 2 is inserted into meter 1. In this embodiment of the present invention, test lead box 2 is suitable for high current measurement mode with a maximum measurement current of 30A, and can measure the test object through test probes 25 and 26.

[0037] like Figure 4 As shown, a protrusion 1011 extending from the inside out is provided on the side wall of the embedded copper insert 101. During the injection molding process of the meter 1 housing, the protrusion 1011 fits into the plastic material of the meter hole, ensuring that the embedded copper insert 101 is positioned firmly and reliably, thus improving the reliability of the contact and fit between the meter terminal box 211 and the embedded copper insert 101 in the meter hole. The protrusion 1011 can take the form of, but is not limited to, dot-shaped, ring-shaped, etc., and one or more protrusions 1011 can be provided as needed.

[0038] The logic circuit described above will be further explained below. For example, a logic circuit capable of detecting three current measurement modes (mA, A, 30A) is used to determine which mode the current meter should enter. The first to third outputs of the logic circuit generate high or low potentials under different detection states, as shown in Table 1.

[0039]

[0040] Table 1

[0041] For example, when no test probes are inserted, the first output terminal of the logic circuit is at a high potential, the second output terminal is at a low potential, and the third output terminal is at a high potential (H is short for high potential, and L is short for low potential). The above potential signals will be sent back to the microcontroller unit (MCU) of the meter, causing the software to determine that this is an abnormal measurement mode. At this time, a warning message will appear on the user interface (such as display 16) to remind the user (e.g., warning message 2: inserted in the current measurement hole). Other warning messages corresponding to different detection states include warning message 1 (inserted in the voltage measurement hole) and warning message 3 (do not insert multiple probes). Therefore, according to the different potentials of each detection state, a code combination that can be read by the microcontroller unit is generated to determine what measurement mode the meter has entered.

[0042] One of the features of this utility model is that, while maintaining the original measurement and detection functions of the first to fourth terminals of the meter and meeting the requirements of international safety standards for high voltage protection, an additional detection function is added to correctly detect externally expanded components, thereby expanding the functionality.

[0043] The second feature of this utility model is that a protrusion from the inside out is provided on the side wall of the embedded copper insert. The protrusion fits into the plastic material of the meter hole, ensuring that the embedded copper insert is positioned firmly and reliably, thereby improving the reliability of the contact and fit between the meter terminal box terminal and the embedded copper insert of the meter hole.

Claims

1. An electronic measuring instrument, comprising: An electricity meter, which is equipped with a first terminal, a second terminal, a third terminal, a fourth terminal, a logic circuit, and a test lead box; The invention is characterized in that the test lead box includes a circuit board, one end of which is provided with a first terminal, a second terminal, a third terminal and a fourth terminal, and the other end of which is provided with a pair of test probes. The first to fourth terminals are respectively inserted into the first to fourth holes. The circuit board is coupled to the third terminal, the fourth terminal and the pair of test probes. Each of the first terminal and the second terminal includes a metal spring. When the first terminal and the second terminal are respectively inserted into the first hole and the second hole, a circuit is formed between the first hole and the second hole through the test lead box, so as to determine whether the meter is plugged into the test lead box through the logic circuit.

2. The electronic measuring instrument as described in claim 1, characterized in that, The third and fourth wells are used to obtain measurement signals from the pair of test probes for measuring the test object.

3. The electronic measuring instrument as described in claim 2, characterized in that, The test box includes a fuse and a current sampling resistor, used to transmit the measurement signal back to the meter.

4. The electronic measuring instrument as described in claim 1, characterized in that, The first hole and the second hole are provided with embedded copper inserts, and the metal springs are respectively disposed on one side of the first terminal and the second terminal. When the first terminal and the second terminal are respectively inserted into the first hole and the second hole, the metal springs respectively contact the embedded copper inserts.

5. The electronic measuring instrument as described in claim 1, characterized in that, The meter includes a microcontroller unit electrically connected to the logic circuit. The microcontroller unit determines the measurement mode that the meter has entered based on the relative high and low potentials between the output terminals of the logic circuit.

6. The electronic measuring instrument as described in claim 5, characterized in that, The meter includes a user interface, which displays a warning message when it is determined that the meter has entered an abnormal measurement mode.

7. The electronic measuring instrument as described in claim 1, characterized in that, The test lead box is suitable for high current measurement mode with a maximum measurement current of 30A.

8. The electronic measuring instrument as described in claim 1, characterized in that, The first hole is for measuring current below 10A, the second hole is for measuring current below 1A, the third hole is for grounding, and the fourth hole is for composite measurement.

9. The electronic measuring instrument as described in claim 8, characterized in that, The composite measuring aperture can measure voltage, resistance, and capacitance.

10. The electronic measuring instrument as described in claim 4, characterized in that, The embedded copper insert includes a protrusion on the insert wall that extends from the inside out, and the protrusion fits into the plastic material of the meter hole.

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