CN211086422U

CN211086422U - Voice prompt protection circuit for preventing digital multimeter from being damaged by misoperation

Info

Publication number: CN211086422U
Application number: CN201920856450.9U
Authority: CN
Inventors: 王伟祥; 师光飞
Original assignee: Wuhan Technical College of Communications
Current assignee: Wuhan Technical College of Communications
Priority date: 2019-05-31
Filing date: 2019-05-31
Publication date: 2020-07-24
Anticipated expiration: 2029-05-31

Abstract

The utility model relates to a prevent that maloperation from damaging digital multimeter's voice prompt protection circuit, protection circuit include 5 gear sensors such as intelligent voice prompt chip, movable contact, resistance, 4 jacks such as V omega, speaker etc.. The intelligent voice prompt chip is internally provided with a microprocessor and can analyze the input signal and output a corresponding voice prompt and control signal. The movable contact is coaxial with a dial of the digital multimeter and can be synchronously communicated with each functional gear sensor in the protection circuit with the dial. When the functional gear position sensors in the protection circuit are switched on by the movable contact, a logic high level is output. The protection circuit contains a microswitch circuit in each jack, and when the meter pen is inserted, a logic high level can be output. Use the utility model discloses protection circuit's digital multimeter can prevent effectively that maloperation such as voltage is surveyed with electric current shelves or other shelves from causing damage universal meter, empty tripping operation, bodily injury etc..

Description

Voice prompt protection circuit for preventing digital multimeter from being damaged by misoperation

Technical Field

The utility model belongs to the electronic measurement instrument field, concretely relates to prevent that maloperation from damaging digital multimeter's voice prompt protection circuit.

Background

Although each function measuring gear of the existing digital multimeter is designed with a protection circuit, when misoperation such as voltage measurement by current gears or other gears occurs to users, the method still causes the following problems: 1. the normal use of the digital multimeter is affected by the damage of peripheral elements (such as a fuse tube) and internal elements (such as an overvoltage protection diode, a shunt resistor and an integrated circuit); 2. the tripping of the indoor main switch is caused, so that large-area power failure is caused, and the normal use of other electrical equipment is influenced; 3. the watch pen is ignited to hurt the hands or eyes of the operator, which causes personal injury accidents. Therefore, a digital multimeter requires a protection circuit that prevents erroneous operation.

SUMMERY OF THE UTILITY MODEL

A voice prompt protection circuit for preventing a digital multimeter from being damaged by misoperation is used for preventing the digital multimeter from being damaged by the misoperation. The protection circuit comprises an intelligent voice prompt chip, a movable contact, a resistance gear sensor, a low-voltage gear sensor, a high-voltage gear sensor, a small-current gear sensor, a large-current gear sensor, a V/omega jack, a COM jack, a mA jack, a 20A jack, a loudspeaker and the like.

When a power switch of the digital multimeter is pressed, the protection circuit can automatically detect whether the jack inserted by the meter pen corresponds to the function gear selected by the dial plate or not. If so, comparing the voice prompt content and the action of the protection circuit with table 1; if not, the voice prompt content and the action of the protection circuit are compared in table 2.

Use the utility model discloses protection circuit's digital multimeter as long as operate according to the voice prompt content, can prevent effectively that maloperation such as measuring voltage with electric current shelves or other shelves from causing accidents such as damage universal meter, empty tripping operation, bodily injury, extension universal meter life still can form operating personnel and measure at every turn and finish the back, inserts V omega jack with the red pen-shape metre plug, dials the good custom of the highest range shelves of voltage with the driver plate. As can be seen from tables 1 and 2:

TABLE 1 voice prompt contents and action comparison table of protection circuit when jack inserted by meter pen corresponds to the function gear selected by dial

TABLE 2 voice prompt contents and action comparison table of protection circuit when the jack inserted by the meter pen does not correspond to the function gear selected by the dial

Drawings

FIG. 1 is a schematic diagram of a protection circuit installed in a digital multimeter;

fig. 2 is a schematic block diagram of the protection circuit.

Detailed Description

Referring to fig. 1 and 2, a voice prompt protection circuit 1 for preventing misoperation from damaging a digital multimeter is installed in the digital multimeter 2 and shares a power supply with the digital multimeter 2. The protection circuit 1 comprises an intelligent voice prompt chip 3, a movable contact 5, a resistance gear sensor 6, a low-voltage gear sensor 7, a high-voltage gear sensor 8, a low-current gear sensor 9, a high-current gear sensor 10, a V/omega jack 11, a COM jack 12, a mA jack 13, a 20A jack 14, a loudspeaker 15 and the like. The intelligent voice prompt chip 3 is internally provided with a microprocessor and can carry out logic analysis on the input signal and output a corresponding voice prompt signal and a corresponding control signal. The movable contact 5 is coaxial with the dial 4 of the digital multimeter 2 and can be synchronously connected with each function gear sensor in the protection circuit with the dial 4. Each functional shift position sensor in the protection circuit 1 can output a logic high level when turned on by the movable contact 5. The V/omega jack 11, the COM jack 12, the mA jack 13 and the 20A jack 14 are arranged on a panel of the digital multimeter 2, each jack internally comprises a microswitch circuit, and when a meter pen plug is inserted, a logic high level can be output.

When measuring, press switch 17 of digital multimeter 2, protection circuit 1 begins to work, intelligent voice prompt chip 3 will be according to V/omega jack 11, COM jack 12, mA jack 13, 20A jack 14, resistance gear sensor 6, low-voltage gear sensor 7, high-voltage gear sensor 8, undercurrent gear sensor 9, heavy current gear sensor 10, etc. device output to its logic level signal, carry out the analysis, judge that the jack that the pen-shape metre plug of digital multimeter 2 inserts corresponds with the function gear that dial 4 of digital multimeter 2 was selected. If the intelligent voice prompt chip 3 corresponds to the digital multimeter, the intelligent voice prompt chip 3 outputs a corresponding voice signal according to the voice prompt content of the multimeter 1, a loudspeaker 15 is driven to sound to remind an operator, after the measurement is finished, a red meter pen plug is inserted into the V/omega jack 11, the dial 4 is dialed to a voltage maximum range gear, if the operator does not execute according to the requirement, meanwhile, the intelligent voice prompt chip 3 detects that the digital multimeter is in a state to be measured again from the A/D converter 18 of the digital multimeter 2 through the input port 21 of the intelligent voice prompt chip, after the voice prompt is repeated for 6 times, the intelligent voice prompt chip 3 triggers the automatic shutdown circuit 19 of the digital multimeter 2 through the output port 20 of the intelligent voice prompt chip to enable the digital multimeter 2 to enter a ' dormant ' state ', and the liquid crystal 16 is black; if not, the intelligent voice prompt chip 3 outputs corresponding voice signals according to the voice prompt contents in the table 2, and drives the loudspeaker 15 to sound. After the voice prompt is repeated for 6 times, when the intelligent voice prompt chip 3 detects that the jack inserted by the pen-shape plug is not corresponding to the selected function gear of the dial plate 4 of the digital multimeter 2, the automatic shutdown circuit 19 of the digital multimeter 2 is triggered through the output port 20 of the intelligent voice prompt chip to enable the digital multimeter to enter a dormant state, and the liquid crystal 16 of the intelligent voice prompt chip is in a black screen state, so that the function of preventing the digital multimeter from being damaged by misoperation through voice prompt by the voice prompt protection circuit 1 is realized. If the normal measurement is to be recovered, the power switch 17 of the digital multimeter 2 is pressed twice.

Claims

1. A voice prompt protection circuit (1) for preventing a digital multimeter from being damaged by misoperation is installed in the digital multimeter and shares a power supply with the digital multimeter and is used for preventing the digital multimeter (2) from being damaged by misoperation, and is characterized by comprising an intelligent voice prompt chip (3), a movable contact (5), a resistance gear sensor (6), a low-voltage gear sensor (7), a high-voltage gear sensor (8), a small-current gear sensor (9), a large-current gear sensor (10), a V/omega jack (11), a COM jack (12), a jack (13), a 20A jack (14) and a loudspeaker (15), wherein the intelligent voice prompt chip (3) is internally provided with a microprocessor and used for carrying out logic analysis on input signals and outputting corresponding voice prompt signals and control signals, the movable contact (5) is coaxial with a drive plate (4) of the digital multimeter (2), can with driver plate (4) each function gear sensor of synchronous switch-on, when resistance gear sensor (6) in protection circuit (1), low-voltage gear sensor (7), high-voltage gear sensor (8), undercurrent gear sensor (9) or heavy current gear sensor (10) and movable contact switch-on, can export logic high level, V/omega jack, COM jack, mA jack, 20A jack dress is on digital multimeter's panel, the inside micro-gap switch circuit that all contains of each jack, when the pen-shape metre plug inserts, can export logic high level.