CN104360122A

CN104360122A - Intelligent digital multimeter with voice broadcast function

Info

Publication number: CN104360122A
Application number: CN201410695832.XA
Authority: CN
Inventors: 王永刚; 胡晶
Original assignee: Harbin Jindu Solar Energy Technology Co Ltd
Current assignee: Harbin Jindu Solar Energy Technology Co Ltd
Priority date: 2014-11-27
Filing date: 2014-11-27
Publication date: 2015-02-18

Abstract

The invention relates to an intelligent digital multimeter with the voice broadcast function. The intelligent digital multimeter comprises a DCV module, a DCA module, an ACV module, an ACA module, a CAP module, an HFE module, a resistor measurement circuit, a diode measurement module, a control module, a voice broadcast module, an automatic power-off circuit and an LCD display circuit. The DCV module, the DCA module, the ACV module, the ACA module, the CAP module, the HFE module, the resistor measurement circuit and the diode measurement circuit are connected with change-over switches, the change-over switches are connected with the control module, the control module is connected with the LCD display circuit, an SPCE061 single-chip microcomputer and a peripheral circuit are adopted in the core of the control module, and the peripheral circuit is provided with three buttons and a voice chip device. The digital multimeter can detect multiple signals, can store data displayed on a digital displayer, and can broadcast numerical values through voice.

Description

A kind of Intelligent digital multimeter of voice broadcast

Technical field

the present invention relates to a kind of type digital multimeter of intelligence, especially a kind of Intelligent digital multimeter of SCM Based band voice broadcast function.

Background technology

since within 1977, first handheld digital multimeter comes out in the world, researcher constantly brings forth new ideas in the function and design of multimeter, and New varieties are introduce on after another.Digital multimeter is a kind of Common Instrument in electric detecting technology, it combines the achievement of electronic technology, computing technique, automatic technology and electric detecting technology,, accuracy of reading, compact easy to operate with it, the advantage such as easy to carry become indispensable instrument in modern surveying, it can measure the forward voltage drop etc. of DC current, alternating current, DC voltage, alternating voltage, resistance, electric capacity, diode, replaces analog (i.e. pointer-type) multimeter just in a lot of fields.There is the advantages such as easy to use, highly sensitive, measuring speed fast, strong, the defeated people's impedance of broad quantum, overload capacity is high, indicated value has objectivity (there is not the collimation error), extended capability is strong.

digital multimeter (DMM), also known as digital multimeter, is a kind of tool-class digital instrument the most frequently used, the most capable in detection of electrons and maintenance job at present.The Digital Measuring Technique that it adopts, by converting thereof into discontinuous, discrete digital quantity to the sampling of continuous print analog quantity (DC input voitage), and shows with tens digit form.Because inside have employed discharge circuit, internal resistance can be done very large, often 1M Europe or larger (namely can obtain higher sensitivity).This makes can be less on the impact of circuit-under-test, and measuring accuracy is higher.Traditional pointer multimeter function singleness, precision are low, can not meet the demand of digital times, and the digital multimeter adopting monolithic a/d converter to form, there is convenient reading, precision is high, the features such as test function is strong, integrated level is high, Micro Energy Lose, antijamming capability are strong, Intelligent digital multimeter in addition with single-chip microcomputer has automatic calibration especially, automatically measures, the several functions such as automatic data processing and real-time communication.

at present, digital multimeter has been widely used in the intelligent measuring field such as electronics and electrotechnical measurement, industrial automation instrument, Auto-Test System, and powerful vitality is shown.Meanwhile, the various general and special digital instrument and meter expanded by DMM, also brings up to brand-new level electricity and non-electrical quantity measuring technology.

the design designs a Intelligent Digital formula universal electric meter that can " speak " in conjunction with the application advantage in digital speech and control technology.Measured value directly can be told gauger by this digital multimeter.Speech utterance function compensate for the plodding defect of product ergonomics interactive interface in the past.

Summary of the invention

the object of the invention is to design a kind of digital multimeter with voice broadcast, the measured value of multimeter, except the test function of common multimeter, directly can also be told gauger in the mode of voice broadcast by this invention.

the object of the present invention is achieved like this:

a kind of Intelligent digital multimeter of voice broadcast, be made up of DCV module, DCA module, ACV module, ACA module, CAP module, HFE module, resistance measuring circuit, diode measurement circuit, voice playing circuit, automatic shutdown circuitry and LCD display circuit, described DCV module, DCA module, ACV module, ACA module, CAP module, HFE module, resistance measuring circuit, diode measurement circuit are connected with switch, switch link control module, control module are connected with LCD display circuit and driving, drive and connect voice playing circuit; Described automatic shutdown circuitry connects single-chip microcomputer.

described control module is SPCE061 single-chip microcomputer and peripheral circuit, and described peripheral circuit is amplifying circuit and voltage shifts circuit; Described peripheral circuit has 3 buttons, the device of a speech chip; Measure DC voltage and adopt the precision metallic resistance that error is less; Measure several grades in DC current and the public switch of alternating current, determine to measure DC current or alternating current by keyswitch K3, measure alternating current when K3 presses, measure DC current when K3 upsprings; Measuring resistance circuit adopts areal survey, and voltage signal is from the 5th pin input of U7B, and amplify through U7B, the attribute arranging IOA2I, OA3 can change the scope of amplifying rear voltage.

design feature of the present invention and beneficial effect:

1, this invention is for digital multimeter, and speech utterance function compensate for the plodding shortcoming of like product man-machine interaction in the past, enhances Consumer's Experience;

2, adopt single-chip microcomputer as control chip, there is low-power consumption, low cost, advantage that volume is little, for fields such as field works, there is special application value;

3, adopt serial communication protocol between each system and modules, ensure that the stability of Signal transmissions.

Accompanying drawing explanation

fig. 1 is system principle structural drawing of the present invention.

fig. 2 is system program process flow diagram of the present invention.

fig. 3 is DC voltage measuring circuit schematic diagram of the present invention.

fig. 4 is rectification of the present invention and filtering circuit schematic diagram.

fig. 5 is LED display routine process flow diagram.

fig. 6 is voice broadcast circuit theory diagrams.

Embodiment

below in conjunction with accompanying drawing, principle of the present invention and concrete annexation are described in more detail:

embodiment 1

composition graphs 1, Fig. 1 is system principle structural drawing of the present invention;

a kind of Intelligent digital multimeter of voice broadcast, it is by DCV module, DCA module, ACV module, ACA module, CAP module, HFE module, resistance measuring circuit, diode measurement circuit, control module, voice playing circuit, automatic shutdown circuitry and LCD display circuit composition, described DCV module, DCA module, ACV module, ACA module, CAP module, HFE module, resistance measuring circuit, diode measurement circuit is connected with switch, switch link control module, control module is connected with LCD display circuit and driving, drive and connect voice playing circuit, described automatic shutdown circuitry connects single-chip microcomputer.

adopt this single-chip microcomputer language process function, voltage, electric current or resistance information that control module will collect, be connected with J3 voice output interface, DAC output signal is amplified through Q1, carry out voice conversion, then export, reported the numerical value of current test by the external loudspeaker of voice generating unit, complete test process.

embodiment 2

fig. 2 is system program process flow diagram of the present invention;

when starting the initialization carrying out system after system electrification, mainly comprise the initialization of controller and the starting condition initialization of each system; After system initialization, enter circulation, the running in this circulation can be divided into three parts: keyboard scan, to arrange sub-state, do corresponding operation according to sub-state according to key assignments; Define base state and sub-state two states in a program; Base state comprises UART unlatching and UART closes two kinds of situations; Sub-state comprises recording, broadcasting, loop play, repeat playing, downloads, uploads, stops totally 7 kinds of situations.

embodiment 3

fig. 3 is DC voltage measuring circuit schematic diagram of the present invention;

in figure, R46-R52 is divider resistance, all employing relative error is the precision metallic resistance of ± 0.5%, the summation of resistance is 10M, U5 (74HC4051) is multiway analog switch, its passage is controlled by IOA9, IOA10, IOA11, for selecting different ranges, DC voltage measuring circuit take 200mV as basic range, establishes 5 grades altogether; After divider resistance dividing potential drop, the voltage that each shelves (tripod by 74HC4051) export all becomes the numerical value within 200mV, and this numerical value delivers to SPCE061 microprocessor detect again after amplifying circuit amplifies.

embodiment 4

fig. 4 is rectification of the present invention and filtering circuit schematic diagram;

u7A(TL062C) and the composition such as diode D7 AC/DC converter, wherein D7 is commutation diode, and D8 is protection diode; U7A is connected into in-phase amplifier, and R53 is negative feedback resistor, and C20 is frequency compensation capacitance, and C21, C18 are capacitance, avoids DC component to cause measuring error; Ac voltage signal after being amplified by U7A exports through capacitance C18, the D7 conducting when signal positive half cycle, D8 cut-off, current path be U7A-> C18-> D7-> R42-> R43-> VR2-> COM(in analog); D8 conducting during signal negative half period, D7 cut-off current path are COM-> VR2-> R43-> R45-> D8-> C18-> U7A.The signal exported from commutation diode D7 negative terminal is pulsating dc voltage, obtains mean voltage V0, deliver to digital direct current voltmeter head and measure after R40, C16 filtering.

embodiment 5

fig. 5 is LED display routine process flow diagram;

the refreshing frequency of LCD is 32Hz, and by 256Hz implement of interruption function, system often enters once interrupts, and count value adds 1, is recycled to 7, and so far LCD is refreshed once.

embodiment 6

fig. 6 is voice broadcast circuit theory diagrams;

each measurement terminates, and by measured value voice broadcast to user, it is voice output interface that SPCE061A has middle J3, external loudspeaker, and DAC output signal is amplified through Q1, then exports voice messaging.

Claims

1. the Intelligent digital multimeter of a voice broadcast, it is characterized in that: it is by DCV module, DCA module, ACV module, ACA module, CAP module, HFE module, resistance measuring circuit, diode measurement circuit, control module, voice playing circuit, automatic shutdown circuitry and LCD display circuit composition, described DCV module, DCA module, ACV module, ACA module, CAP module, HFE module, resistance measuring circuit, diode measurement circuit is connected with switch, switch link control module, control module is connected with LCD display circuit and driving, drive and connect voice playing circuit, described automatic shutdown circuitry connects single-chip microcomputer.

2. the Intelligent digital multimeter of a kind of voice broadcast according to claim 1, is characterized in that: described control module is SPCE061 single-chip microcomputer and peripheral circuit, and described peripheral circuit is amplifying circuit and voltage shifts circuit; Described peripheral circuit has 3 buttons, the device of a speech chip; Measure DC voltage and adopt the precision metallic resistance that error is less; Measure several grades in DC current and the public switch of alternating current, determine to measure DC current or alternating current by keyswitch K3, measure alternating current when K3 presses, measure DC current when K3 upsprings; Measuring resistance circuit adopts areal survey, and voltage signal is from the 5th pin input of U7B, and amplify through U7B, the attribute arranging IOA2I, OA3 can change the scope of amplifying rear voltage.