A multimeter intelligent module with power-on alarm and self-locking functions

Abstract

The present invention belongs to the field of measurement and control technology and instrument technology, and specifically relates to a multimeter intelligent module with power-on alarm and self-locking functions. The housing is provided with slots of different sizes, including a limit switch slot for accommodating a limit switch, a battery slot for accommodating a battery, a circuit board slot for accommodating a single-chip microcomputer, etc., a speaker slot for accommodating a speaker, a test lead jack connected to a multimeter jack, and a multimeter slot for accommodating a multimeter body. The housing is also designed with a knob and a baffle, the knob fits with the multimeter knob, and the baffle is connected to the multimeter slot cavity to fix the multimeter; the single-chip microcomputer is respectively connected to an A / D conversion chip, a voice broadcast module, a limit switch, an indicator light, and a driver chip; the A / D conversion chip is connected to a linear regulator, the voice broadcast module is connected to a speaker, and the driver chip is connected to a relay. The present invention can avoid safety accidents caused by the test lead position not matching the selected gear, and can avoid safety hazards caused by human error.

Description

Technical Field

[0001] The invention belongs to the field of measurement and control technology and instrument technology, and particularly relates to a multimeter intelligent module with live alarm and self-locking functions. Background Art

[0002] Multimeters can be used to measure resistance, AC / DC voltage, AC / DC current, and capacitance. They can also test the condition of diodes, transistors, and voltage regulators. Multimeters are generally suitable for online voltage, resistance, and continuity measurements on electrical and instrumentation equipment. Multimeters offer the following functions: locating cable breaks, checking for moisture, detecting shorts or opens in lighting circuits, inspecting control circuits, and checking main circuits. Domestic and international multimeter testers are standard testers, designed solely to connect the multimeter to the object under test. These meters have the following drawbacks: If the current, continuity, or resistance range is mistakenly used when measuring voltage in a control circuit, the circuit under test can become conductive, causing a short circuit and unexpected control function activation. In severe cases, this can lead to production line shutdown, generator tripping, transmission line tripping, power loss, equipment damage, and personal injury. With the continuous development of automation and intelligent manufacturing technologies, the intelligentization of multimeters has gradually become a research focus. However, existing research results have all directly modified the internal structure of the multimeter. At the same time, most intelligent multimeters on the market are intelligent in the form of automatic switching of gears when measuring resistance, voltage, and on / off, and there are fewer achievements in voice prompts. Overall, the intelligentization of multimeters currently on the market starts from the inside of the multimeter, by installing a single-chip microcomputer to control the on / off control of the circuit. In other words, the entire internal circuit of the multimeter needs to be replanned and redesigned, rather than improving the original circuit and adding auxiliary functions.

[0003] Research efforts at home and abroad to modify multimeters have primarily focused on internal circuitry. Existing smart multimeters often suffer from the following drawbacks: manual probe changes are still required when switching between current and voltage measurements, leading to mismatches between meter settings and probe jacks; and inaccurate smart identification. While attempts to modify handheld multimeters using external packaging have yielded limited success, improving multimeters from the outside reduces development effort and allows for automatic probe switching. Therefore, research and implementation of intelligent multimeters by adding external packaging is warranted. Summary of the Invention

[0004] The present invention aims to provide an intelligent multimeter module with live alarm and self-locking functions. This intelligent multimeter module assists users in using the multimeter, primarily by providing voice prompts indicating the current gear position, connecting the test leads to the corresponding gear jack, and performing a safety check before connecting the circuit to the multimeter. After confirming the gear selection, certain gear positions require a safety check. This involves analyzing the circuit under test to determine whether it complies with the user-selected gear position. Prior to this safety check, a circuit continuity check is necessary to determine whether the user has connected the test leads to the gear position under test.

[0005] The purpose of this is to address various accidents and economic losses caused by mismatches between the measured object and the measurement range. If, when measuring voltage in a control circuit, the current, continuity, or resistance range is mistakenly used, the circuit under test can short-circuit the power supply and cause unexpected control function activation. In severe cases, this can lead to production line shutdown, generator tripping, transmission line tripping, power loss, equipment damage, and personal injury. Therefore, this multimeter-compatible protection module technically eliminates the significant risks of equipment damage, personal injury, and production line downtime caused by mistakenly measuring live circuits using the resistance or continuity range of the multimeter.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A multimeter intelligent module with power-on alarm and self-locking functions:

[0008] Mechanical structure: The outer shell is provided with slots of different sizes, including a limit switch slot for accommodating a limit switch, a battery slot for accommodating a battery, a circuit board slot for accommodating a single-chip microcomputer, an A / D conversion chip, a linear voltage regulator, a voice broadcast module, an indicator light, a driver chip, and a relay, a speaker slot for accommodating a speaker, a test lead jack connected to a multimeter jack, and a multimeter slot for accommodating a multimeter body. The outer shell is also provided with a knob and a baffle, the knob fits with the multimeter knob, and the baffle is connected to the multimeter slot cavity to fix the multimeter.

[0009] Circuit structure part: The single chip microcomputer is connected to the A / D conversion chip, voice broadcast module, limit switch, indicator light, and driver chip respectively; the A / D conversion chip is connected to the linear regulator; the voice broadcast module is connected to the speaker; and the driver chip is connected to the relay.

[0010] The limit switch slot, knob, baffle, battery slot, circuit board slot, speaker slot, test lead jack, and multimeter slot are all encapsulated in the shell, and the only visible part on the shell surface is the test lead jack.

[0011] The microcontroller is an STM32F103C8T6 microcontroller, a GD32F103C8T6 microcontroller, or an APM32F103C8T6 microcontroller.

[0012] The A / D conversion chip is AD7606 chip or CBM76AD06 chip.

[0013] The linear regulator has an accuracy of less than 0.1V and a maximum output current greater than 1A.

[0014] The maximum power of the voice broadcast module does not exceed 3W.

[0015] The limit switch model is KW12.

[0016] The speaker is 8Ω, 0.5W, and has a diameter of 45mm.

[0017] The relay has a rated current of more than 10A and a power supply of 5V.

[0018] 1) Gear selection: When the knob is rotated to the specified gear, the multimeter knob is also rotated to the specified gear. At this time, the baffle triggers the limit switch contact to close. The contact closure signal is transmitted to the single-chip microcomputer in 0 / 1 mode. The single-chip microcomputer judges the signal and confirms the specific gear position it corresponds to. The judgment result signal is transmitted to the voice broadcast module via serial communication. The voice broadcast module processes it into a standard sentence and transmits it to the speaker for broadcast;

[0019] 2) Measured signal acquisition: After the gear selection is completed, the test lead is connected to the circuit under test, and an analog signal is obtained through the metal pen tip and wire. The analog signal is first filtered and clamped by a linear regulator and converted into a signal range accepted by the A / D converter chip. It is then transmitted to the A / D converter chip, which converts the analog signal collected in the measured circuit into a digital signal that can be processed by the microcontroller;

[0020] 3) Measured signal processing: After the measured signal is collected, the A / D conversion chip transmits the digital signal to the microcontroller through the serial port. The microcontroller receives the signal and compares it with the contact displacement signal transmitted by the limit switch to confirm the consistency of the two signals. Only when the two signals are consistent are they considered correct; all other results are considered incorrect.

[0021] 4) Broadcasting of test results: After the processing of the measured signal is completed, the single-chip microcomputer transmits the judgment result in digital signal mode to the voice broadcast module via the serial port. If the detection result of the measured signal is consistent with the gear selection, it is considered that the gear selection is correct. The single-chip microcomputer outputs a signal to the driver chip. The driver chip receives the signal and outputs a voltage that can drive the relay to both ends of the relay coil, so that its contacts are closed and the original measurement circuit of the multimeter is connected; if the detection result of the measured signal is inconsistent with the gear selection, it is considered that the gear selection is incorrect. At this time, the single-chip microcomputer determines the detailed inconsistency and outputs the corresponding signal of the judgment result to the voice broadcast module via the serial port. The voice broadcast module then drives the speaker to broadcast the specified prompt sentence through the standard sentence, and drives the indicator light to flash at the same time.

[0022] The beneficial effects achieved by the present invention are:

[0023] 1. The intelligent gear selection technology achieves the technical effect of matching the gear selected by the multimeter with the corresponding jack position of the test lead, automatically connecting to the correct test lead jack. Compared with traditional multimeters, it can avoid safety accidents caused by the mismatch between the test lead position and the selected gear.

[0024] 2. The intelligent stop measurement technology prohibits access when it is clearly found that the selected gear cannot be connected to the circuit under test, thereby protecting the multimeter and the circuit under test. Compared with traditional multimeters, it can avoid safety hazards caused by human errors.

[0025] 3. The technical means of voice and prompts can provide clear prompts when there is improper operation. It can not only detect the problem but also provide the corresponding correct operation method.

[0026] 4. The technical means of intelligent multimeter have achieved the technical effect of intelligent transformation of the original high-precision multimeter. Compared with the smart multimeters on the market, the technical effect of intelligent multimeter has been achieved without eliminating the original multimeter. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a mechanical structure diagram of a multimeter intelligent module with power-on alarm and self-locking functions;

[0028] Figure 2 This is a schematic diagram of the circuit structure of a multimeter intelligent module with power-on alarm and self-locking functions;

[0029] Figure 3 This is a working diagram of a multimeter intelligent module with live alarm and self-locking functions;

[0030] In the figure: 1—limit switch slot; 2—knob; 3—baffle; 4—battery slot; 5—circuit board slot; 6—speaker slot; 7—test lead jack; 8—multimeter slot; 9—housing; 10—microcontroller; 11—A / D converter chip; 12—linear regulator; 13—voice broadcast module; 14—limit switch; 15—indicator light; 16—speaker; 17—driver chip; 18—relay. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] The mechanical structure consists of Figure 1 The housing 9 is composed of components 1-9. Slots of varying sizes are defined on the housing 9. These include a limit switch slot 1 for accommodating a limit switch 14, a battery slot 4 for accommodating a battery, a circuit board slot 5 for accommodating a microcontroller 10, an A / D converter chip 11, a linear voltage regulator 12, a voice broadcast module 13, an indicator light 15, a driver chip 17, and a relay 18. A speaker slot 6 accommodates a speaker 16. A test lead jack 7 connects to the multimeter jack; when a test lead is inserted, it also connects to the multimeter jack. Multimeter slot 8 accommodates the multimeter body. The housing 9 also features a knob 2 and a baffle 3. Knob 2 mates with the multimeter knob, ensuring that the knob rotates to the designated position. Baffle 3 connects to the cavity of multimeter slot 8, securing the multimeter. In its complete form, components 1-8 are enclosed within the housing 9, with the only visible surface area being the test lead jack 7.

[0033] The circuit structure includes a single-chip microcomputer 10, an A / D conversion chip 11, a linear voltage regulator 12, a voice broadcast module 13, a limit switch 14, an indicator light 15, a speaker 16, a driver chip 17, and a relay 18. The single-chip microcomputer 10 is connected to the A / D conversion chip 11, the voice broadcast module 13, the limit switch 14, the indicator light 15, and the driver chip 17 respectively. The A / D conversion chip 11 is connected to the linear voltage regulator 12, the voice broadcast module 13 is connected to the speaker 16, and the driver chip 17 is connected to the relay 18.

[0034] 1) Gear selection: Knob 2 is rotated to the specified gear, which also drives the multimeter knob to rotate to the specified gear. At this time, the baffle 3 triggers the limit switch 14 to close the contact. The contact closure signal is transmitted to the single-chip microcomputer 10 in a 0 / 1 manner. The single-chip microcomputer 10 judges the signal and confirms the specific gear position it corresponds to. The judgment result signal is transmitted to the voice broadcast module 13 via serial communication. The voice broadcast module 13 processes it into a standard sentence and transmits it to the speaker 16 for broadcast;

[0035] 2) Measured signal acquisition: After the gear selection is completed, the test lead is connected to the circuit under test, and an analog signal is obtained through the metal pen tip and the wire. The analog signal is first filtered and clamped by the linear regulator 12 and converted into a signal range accepted by the A / D conversion chip 11. It is then transmitted to the A / D conversion chip 11, which converts the analog signal collected in the measured circuit into a digital signal that can be processed by the single-chip microcomputer 10;

[0036] 3) Measured signal processing: After the measured signal is collected, the A / D conversion chip 11 transmits the digital signal to the single-chip microcomputer 10 via the serial port. The single-chip microcomputer receives the signal and compares it with the contact displacement signal transmitted by the limit switch 14 to confirm the consistency of the two signals. Only when the two signals are consistent are they considered correct; otherwise, they are considered incorrect.

[0037] 4) Broadcasting of test results: After the processing of the measured signal is completed, the single-chip microcomputer 10 transmits the judgment result in digital signal mode to the voice broadcast module 13 via the serial port. If the detection result of the measured signal is consistent with the gear selection, it is considered that the gear selection is correct. The single-chip microcomputer outputs a signal to the driver chip 17. The driver chip 17 receives the signal and outputs a voltage that can drive the relay 18 to both ends of the relay coil, so that its contacts are closed and the original measurement circuit of the multimeter is connected; if the detection result of the measured signal is inconsistent with the gear selection, it is considered that the gear selection is incorrect. At this time, the single-chip microcomputer determines the detailed inconsistency (such as using the resistance gear to measure the voltage signal) and outputs the corresponding signal of the judgment result to the voice broadcast module 13 via the serial port. The voice broadcast module 13 then drives the speaker 16 to broadcast the specified prompt sentence through the standard sentence, and drives the indicator light 15 to flash.

[0038] Component limitation requirements:

[0039] Battery: 7.4V, 6800mAh, 4-cell, two-series, two-parallel, 18650mAh;

[0040] MCU 10: limited to STM32F103C8T6 MCU, which can be replaced by GD32F103C8T6 MCU and APM32F103C8T6 MCU;

[0041] A / D conversion chip 11: limited to AD7606 chip, can be replaced by CBM76AD06 chip;

[0042] Linear voltage regulator 12: accuracy less than 0.1V, maximum output current greater than 1A;

[0043] Voice broadcast module 13: Maximum power does not exceed 3W;

[0044] Limit switch 14: silver contact, 5A, 250V micro switch, model KW12;

[0045] Indicator light 15: 3.0-3.2V, 20mA, 1200-1500mcd;

[0046] Speaker 16: 8Ω, 0.5W, 45mm diameter;

[0047] Relay 18: A relay with a rated current of 10A or more and a power supply of 5V.

Claims

1. A multimeter intelligent module with live alarm and self-locking functions, characterized by: Mechanical structure: The outer shell is provided with slots of different sizes, including a limit switch slot for accommodating a limit switch, a battery slot for accommodating a battery, a circuit board slot for accommodating a single-chip microcomputer, an A / D conversion chip, a linear voltage regulator, a voice broadcast module, an indicator light, a driver chip, and a relay, a speaker slot for accommodating a speaker, a test lead jack connected to a multimeter jack, and a multimeter slot for accommodating a multimeter body. The outer shell is also provided with a knob and a baffle, the knob fits with the multimeter knob, and the baffle is connected to the multimeter slot cavity to fix the multimeter. Circuit structure: The single chip microcomputer is connected to the A / D conversion chip, voice broadcast module, limit switch, indicator light, and driver chip respectively; the A / D conversion chip is connected to the linear regulator; the voice broadcast module is connected to the speaker; and the driver chip is connected to the relay; 1) Gear selection: When the knob is rotated to the specified gear, the multimeter knob is also rotated to the specified gear. At this time, the baffle triggers the limit switch contact to close. The contact closure signal is transmitted to the single-chip microcomputer in 0 / 1 mode. The single-chip microcomputer judges the signal and confirms the specific gear position it corresponds to. The judgment result signal is transmitted to the voice broadcast module via serial communication. The voice broadcast module processes it into a standard sentence and transmits it to the speaker for broadcast; 2) Measured signal acquisition: After the gear selection is completed, the test lead is connected to the circuit under test, and an analog signal is obtained through the metal pen tip and wire. The analog signal is first filtered and clamped by a linear regulator and converted into a signal range accepted by the A / D converter chip. It is then transmitted to the A / D converter chip, which converts the analog signal collected in the measured circuit into a digital signal that can be processed by the microcontroller; 3) Measured signal processing: After the measured signal is collected, the A / D conversion chip transmits the digital signal to the microcontroller through the serial port. The microcontroller receives the signal and compares it with the contact displacement signal transmitted by the limit switch to confirm the consistency of the two signals. Only when the two signals are consistent are they considered correct; all other results are considered incorrect. 4) Broadcasting of test results: After the processing of the measured signal is completed, the single-chip microcomputer transmits the judgment result in digital signal mode to the voice broadcast module via the serial port. If the detection result of the measured signal is consistent with the gear selection, it is considered that the gear selection is correct. The single-chip microcomputer outputs a signal to the driver chip. The driver chip receives the signal and outputs a voltage that can drive the relay to both ends of the relay coil, so that its contacts are closed and the original measurement circuit of the multimeter is connected; if the detection result of the measured signal is inconsistent with the gear selection, it is considered that the gear selection is incorrect. At this time, the single-chip microcomputer determines the detailed inconsistency and outputs the corresponding signal of the judgment result to the voice broadcast module via the serial port. The voice broadcast module then drives the speaker to broadcast the specified prompt sentence through the standard sentence, and drives the indicator light to flash at the same time.

2. The multimeter intelligent module with live alarm and self-locking function according to claim 1 is characterized in that: The limit switch slot, knob, baffle, battery slot, circuit board slot, speaker slot, test lead jack, and multimeter slot are all encapsulated in the shell, and the only visible part on the shell surface is the test lead jack.

3. The multimeter intelligent module with live alarm and self-locking functions according to claim 1 is characterized in that: The microcontroller is an STM32F103C8T6 microcontroller, a GD32F103C8T6 microcontroller, or an APM32F103C8T6 microcontroller.

4. The multimeter intelligent module with live alarm and self-locking function according to claim 1 is characterized in that: The A / D conversion chip is AD7606 chip or CBM76AD06 chip.

5. The multimeter intelligent module with live alarm and self-locking function according to claim 1 is characterized in that: The linear regulator has an accuracy of less than 0.1V and a maximum output current greater than 1A.

6. The multimeter intelligent module with live alarm and self-locking function according to claim 1, characterized in that: The maximum power of the voice broadcast module does not exceed 3W.

7. The multimeter intelligent module with live alarm and self-locking functions according to claim 1, characterized in that: The limit switch model is KW12.

8. The multimeter intelligent module with live alarm and self-locking functions according to claim 1, characterized in that: The speaker is 8Ω, 0.5W, and has a diameter of 45mm.

9. The multimeter intelligent module with live alarm and self-locking functions according to claim 1, characterized in that: The relay has a rated current of more than 10A and a power supply of 5V.

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