CN209198519U - A kind of simple digital multimeter that experimental teaching is applicable - Google Patents
A kind of simple digital multimeter that experimental teaching is applicable Download PDFInfo
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- CN209198519U CN209198519U CN201822042357.2U CN201822042357U CN209198519U CN 209198519 U CN209198519 U CN 209198519U CN 201822042357 U CN201822042357 U CN 201822042357U CN 209198519 U CN209198519 U CN 209198519U
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Abstract
The utility model belongs to teaching instrument and equipment technical field, more particularly to the simple digital multimeter that a kind of experimental teaching is applicable, including FPGA, program-controlled multichannel division module, virtual value detection module, low-pass filtering module, program-controlled big signal division module, clipping module, analog-to-digital conversion module, square wave oscillation module, sine-wave oscillation module, Shaping Module and LCD touch display screen module；FPGA is separately connected square wave oscillation module, Shaping Module, LCD touch display screen module, analog-to-digital conversion module, program-controlled multichannel division module and program-controlled big signal division module；Shaping Module is connect with sine-wave oscillation module, and analog-to-digital conversion module is connect with program-controlled multichannel division module, low-pass filtering module and clipping module respectively, and low-pass filtering module connects virtual value detection module, and clipping module connects program-controlled big signal division module.The digital multimeter realizes the automatic conversion of range, and precision is higher, can meet the requirement during teaching experiment.
Description
Technical field
The simple number that the utility model belongs to teaching instrument and equipment technical field more particularly to a kind of experimental teaching is applicable in
Multimeter.
Background technique
Digital multimeter integrates the functions such as resistance measurement, current measurement, ac voltage measurement, DC voltage measurement,
Small volume and less weight and precision is higher, is all widely applied, and in Electronics Specialties in fields such as electronics technology, daily lifes
It plays an important role in experimental teaching.Resistance, capacitor, inductance are common device in experimental teaching, and conventional numerical
Though multimeter is able to satisfy most of use demand, lack inductance measurement function more；It is whole that AC measurment multi-pass crosses diode detection
Stream carries out, can measured frequency range it is lower and be difficult to accurately measure the complicated wave form alternating voltage that occurs in actual circuit；Need hand more
Turn changes range, exists because range chooses the improper risk damaged.Such digital multimeter is designed thus, and function is more complete.
Precision is fine, and is able to achieve the automatic conversion of range, it is desirable to provide more conveniences for related experiment teaching.
Utility model content
The purpose of the utility model is to provide a kind of higher digital versatiles for meeting teaching experiment of automatic measuring range precision
Table.It increases inductance measurement and is exchanged not higher than 100kHz, direct current biasing no more than any of ± 500mV with highest subfrequency
Signal voltage measures function.
A kind of simple number that experimental teaching is applicable that in order to achieve the above purposes, the technical solution adopted by the utility model is:
Multimeter, including FPGA, program-controlled multichannel division module, virtual value detection module, low-pass filtering module, program-controlled big signal partial pressure
Module, clipping module, analog-to-digital conversion module, square wave oscillation module, sine-wave oscillation module, Shaping Module and LCD touch aobvious
Display screen module；FPGA be separately connected square wave oscillation module, Shaping Module, LCD touch display screen module, analog-to-digital conversion module,
Program-controlled multichannel division module and program-controlled big signal division module；Shaping Module is connect with sine-wave oscillation module, analog-to-digital conversion
Module is connect with program-controlled multichannel division module, low-pass filtering module and clipping module respectively, and low-pass filtering module connection is effective
It is worth detection module, clipping module connects program-controlled big signal division module；
Program-controlled multichannel division module is exported for generating different voltage values to analog-to-digital conversion module, and it is defeated to receive FPGA
Channel control signals out；As testing resistance interface；
Program-controlled big signal division module is used to for DC voltage to be measured to be classified decaying and extremely limits the voltage output after decaying
Width module receives the gate control signal of FPGA output；As DC voltage interface to be measured；
Clipping module is used to the signal limiter after program-controlled big signal division module decaying be 5V to protect FPGA, and will limit
Signal after width is exported to analog-to-digital conversion module；
Virtual value detection module is used to generate corresponding direct current signal according to AC signal to be measured and is transmitted to low-pass filtering
Module；As alternating voltage interface to be measured；
Low-pass filtering module is for filtering out the AC noise in direct current signal and filtered direct current signal being transmitted to mould-
Number conversion module；
Square wave oscillation module is used to generate the square-wave signal of different frequency according to testing capacitance value and is transmitted to FPGA；
As testing capacitance interface；
Pure oscillation module is used to generate the sinusoidal signal of different frequency according to inductance value to be measured and is transmitted to Shaping Module；
As inductive interface to be measured；
Shaping Module is used to that sinusoidal signal to be shaped as to same frequency with the square-wave signal of phase and is transferred to FPGA；
Analog-to-digital conversion module is used to receive d. c. voltage signal, the program-controlled big signal that program-controlled multichannel division module generates
Division module generates and the clipping d. c. voltage signal through clipping module transmission, virtual value detection module generate and low-pass filtered
The d. c. voltage signal of module transfer；D. c. voltage signal is generated into digital signal and is transmitted to FPGA；
LCD touch display screen module is used to generate touch screen control signal according to artificial touch operation and is transmitted to FPGA,
It receives the display screen control signal that FPGA is generated and signal is controlled according to display screen and show corresponding contents；
The rectangular wave letter that FPGA is used to receive the digital signal of analog-to-digital conversion module generation, square wave oscillation module generates
Number, Shaping Module generate square-wave signal, LCD touch display screen module generate touch screen control signal；According to touch screen control
The operating mode of signal behavior FPGA；Based on digital signal by being generated in the case where measuring resistance mode according to analog-to-digital conversion module
It calculates corresponding voltage value and generates channel control signals and be transmitted to program-controlled multichannel division module, in the case where measuring resistance mode according to logical
Road control signal and voltage value, which are calculated resistance value and generate display screen control signal, is transmitted to LCD touch display screen module；
Digital signal for being generated in the case where measuring DC voltage mode according to analog-to-digital conversion module calculates corresponding voltage value and generates choosing
Logical control signal is transmitted to program-controlled big voltage module, in the case where measuring DC voltage mode according to gate control signal and calculating
Obtained voltage value, which calculates actual DC voltage value and generates display screen control signal, is transmitted to LCD touch display screen module；With
In the range value for directly calculating AC signal according to the digital signal that analog-to-digital conversion module generates in the case where measuring AC voltage profile
And it generates display screen control signal and is transmitted to LCD touch display screen module；For being shaken in the case where measuring capacitance mode according to rectangular wave
The square-wave signal for swinging module generation, which is calculated capacitance and generates display screen control signal, is transmitted to LCD touch display screen mould
Block；Based on square-wave signal by generating again shaped module shaping output according to sine-wave oscillation module in the case where measuring inductive mode
Calculation obtain inductance value and generate display screen control signal be transmitted to LCD touch display screen module.
In the simple digital multimeter that above-mentioned experimental teaching is applicable in, FPGA uses EP4CE0F23C8, program-controlled multichannel
Division module uses REF5025 chip, CD4052B chip and TLV07 chip, virtual value detection module using AD637 chip and
OPA842 chip, low-pass filtering module use trap, and program-controlled big signal division module uses relay HK4100F-DC5V-
SHG, clipping module use OPA227 chip, and analog-to-digital conversion module uses ADS1118 chip, and square wave oscillation module uses
NE555 chip, sine-wave oscillation module use triode 9013, and Shaping Module uses LM311 chip, LCD touch display screen mould
Block uses ALIENTEK ATK-7TFTLCD-V22.
The utility model has the beneficial effects that increasing inductance measurement and highest subfrequency not higher than 100kHz, direct current
Biasing is not more than any AC signal voltage measurement function of ± 500mV, and realizes the automatic conversion of range, and precision is higher,
The requirement during teaching experiment can be met.
Detailed description of the invention
Fig. 1 is the utility model one embodiment digital multimeter structural block diagram；
Fig. 2 is the program-controlled multichannel division module circuit diagram of the utility model one embodiment；
Fig. 3 is the utility model one embodiment virtual value detection module circuit diagram；
Fig. 4 is the program-controlled big signal partial pressure of the utility model one embodiment and clipping module circuit diagram；
Fig. 5 is the utility model one embodiment analog-to-digital conversion module circuit diagram；
Fig. 6 is the utility model one embodiment square wave oscillation module circuit diagram；
Fig. 7 is the utility model one embodiment sine-wave oscillation and Shaping Module circuit diagram.
Specific embodiment
By following detailed description combination attached drawing it will be further appreciated that the characteristics of the utility model and advantage.It is provided
Embodiment is only the explanation to the utility model method, remaining content without limiting the utility model announcement in any way.
The embodiments of the present invention is described in detail with reference to the accompanying drawing.
The present embodiment is achieved through the following technical solutions, as shown in Figure 1, the simple number that a kind of experimental teaching is applicable
Word multimeter, comprising: on-site programmable gate array FPGA, program-controlled multichannel division module, virtual value detection module, low-pass filtering
Module, program-controlled big signal division module, clipping module, analog-to-digital conversion module, square wave oscillation module, sine-wave oscillation module,
Shaping Module, LCD touch display screen module；Program-controlled multichannel division module is connect with analog-to-digital conversion module by conducting wire；Effectively
Value detection module, low-pass filtering module are sequentially connected in series with analog-to-digital conversion module by conducting wire；Program-controlled big signal divides mould
Block, clipping module and analog-to-digital conversion module are sequentially connected in series by conducting wire；Analog-to-digital conversion module and FPGA are connected by conducting wire
It connects；Square wave oscillation module is connect with FPGA by conducting wire；Sine-wave oscillation module, Shaping Module and FPGA are successively gone here and there by conducting wire
Connection connection；FPGA is connect with LCD touch display screen module by conducting wire；FPGA and program-controlled multichannel division module are connected by conducting wire
It connects；FPGA is connect with program-controlled big signal division module by conducting wire.
It exports as shown in Fig. 2, program-controlled multichannel division module generates different voltage values using electric resistance partial pressure principle to mould-
Number conversion modules, for receive FPGA output channel control signals B, A --- wherein B, A are binary number and can combine shape
At 0 (00), 1 (01), 2 (10), 3 (11) four kinds of channel control signals, the divider resistance is chosen to be when channel control signals are 0
200 ohm of partial pressure channel chooses the partial pressure channel that divider resistance is 2000 ohm when channel control signals are 1, in channel
Control signal chooses the partial pressure channel that divider resistance is 20000 ohm when being 2, and partial pressure electricity is chosen when channel control signals are 3
The partial pressure channel that resistance is 200000 ohm.
As shown in figure 4, program-controlled big signal division module by DC voltage to be measured be classified decaying and by the voltage after decaying it is defeated
Out to clipping module, the gate control signal of FPGA output is received, setting decaying multiplying power is when gate control signal is 0
0.2353, when gate control signal is 1, setting decaying multiplying power is 1 (i.e. unattenuated).
Also, the signal limiter after clipping module decays program-controlled big signal division module is 5V to protect FPGA, and will
Signal after clipping is exported to analog-to-digital conversion module.
As shown in figure 3, virtual value detection module generates corresponding direct current signal according to AC signal to be measured and is transmitted to low
Pass filtering module.
Also, low-pass filtering module filters out the AC noise in direct current signal and is transmitted to filtered direct current signal
Analog-to-digital conversion module.
As shown in fig. 6, square wave oscillation module generates square-wave signal and the transmission of different frequency according to testing capacitance value
To FPGA.
As shown in fig. 7, pure oscillation module generates the sinusoidal signal of different frequency according to inductance value to be measured and is transmitted to whole
Shape module.Sinusoidal signal is shaped as same frequency with the square-wave signal of phase and is transferred to FPGA by Shaping Module.
As shown in figure 5, analog-to-digital conversion module receives the d. c. voltage signal that program-controlled multichannel division module generates, receive
The clipping direct current signal that program-controlled big signal division module is generated and transmitted through clipping module receives virtual value detection module and generates simultaneously
The direct current signal of low-pass filtered module transfer generates digital signal according to d. c. voltage signal and is transmitted to FPGA.
Also, LCD touch display screen module generates touch screen control signal according to artificial touch operation and is transmitted to FPGA,
It receives the display screen control signal that FPGA is generated and signal is controlled according to display screen and show corresponding contents.
Also, FPGA receives the digital signal that analog-to-digital conversion module generates, and receives the rectangle that square wave oscillation module generates
Wave signal receives the square-wave signal that Shaping Module generates, and receives LCD touch display screen module and generates touch screen control signal, root
According to the operating mode of touch screen control signal behavior FPGA, shares measurement resistance, measurement DC voltage, measurement alternating voltage, surveys
Measure capacitor and measurement 5 kinds of operating modes of inductance.The digital signal meter generated in the case where measuring resistance mode according to analog-to-digital conversion module
It calculates corresponding voltage value and generates channel control signals and be transmitted to program-controlled multichannel division module, work as calculating in the case where measuring resistance mode
Obtained voltage value makes channel control signals numerical value subtract 1 when being greater than 3.8V (control minimum 0) of signal numerical value is measuring resistive mode
Channel control signals numerical value is set to add for 1 (control signal numerical value is up to 3) under formula when the voltage value being calculated is less than 1.2V,
Resistance value is calculated according to channel control signals and voltage value under measurement resistance mode and generates display screen control signal transmission
To LCD touch display screen module, the digital signal calculating pair generated in the case where measuring DC voltage mode according to analog-to-digital conversion module
It answers voltage value and generates gate control signal and be transmitted to program-controlled big voltage module, work as calculating in the case where measuring DC voltage mode
Gate control signal is set 0 when obtained voltage value is greater than 4.000V, in the case where measuring DC voltage mode when the electricity being calculated
Pressure value, which is less than when 0.964V and gate control signal are 0, sets 1 for gate control signal, in the case where measuring DC voltage mode according to choosing
Logical control signal, which calculates actual DC voltage value with the voltage value being calculated and generates display screen control signal, is transmitted to LCD touching
Display panel module is touched, exchange is directly calculated according to the digital signal that analog-to-digital conversion module generates in the case where measuring AC voltage profile
The range value of signal and generate display screen control signal be transmitted to LCD touch display screen module, the basis in the case where measuring capacitance mode
The square-wave signal that square wave oscillation module generates, which is calculated capacitance and generates display screen control signal, is transmitted to LCD touch
Display panel module is believed in the case where measuring inductive mode according to the square wave that sine-wave oscillation module generates again shaped module shaping output
Number inductance value is calculated and generates display screen control signal and is transmitted to LCD touch display screen module.
FPGA uses EP4CE0F23C8；Program-controlled multichannel division module using REF5025 chip, CD4052B chip and
TLV07 chip；Virtual value detection module uses AD637 chip and OPA842 chip；Low-pass filtering module uses trap；It is program-controlled
Big signal division module uses relay HK4100F-DC5V-SHG；Clipping module uses OPA227 chip；Analog-to-digital conversion module
Using ADS1118 chip；Square wave oscillation module uses NE555 chip；Sine-wave oscillation module uses triode 9013；Shaping
Module uses LM311 chip；LCD touch display screen module uses ALIENTEK ATK-7 TFTLCD-V22.
It should be understood that the part that this specification does not elaborate belongs to the prior art.
Although being described in conjunction with the accompanying specific embodiment of the present utility model above, those of ordinary skill in the art
It should be appreciated that these are merely examples, various deformation or modification can be made to these embodiments, it is practical without departing from this
Novel principle and essence.The scope of the utility model is only limited by the claims that follow.
Claims (2)
1. a kind of applicable simple digital multimeter of experimental teaching, characterized in that including FPGA, program-controlled multichannel division module,
Virtual value detection module, low-pass filtering module, program-controlled big signal division module, clipping module, analog-to-digital conversion module, rectangular wave
Oscillation module, sine-wave oscillation module, Shaping Module and LCD touch display screen module；FPGA is separately connected square wave oscillation mould
Block, Shaping Module, LCD touch display screen module, analog-to-digital conversion module, program-controlled multichannel division module and program-controlled big signal point
Die block；Shaping Module is connect with sine-wave oscillation module, analog-to-digital conversion module respectively with program-controlled multichannel division module, low
Pass filtering module is connected with clipping module, and low-pass filtering module connects virtual value detection module, and clipping module connects program-controlled big letter
Number division module；
Program-controlled multichannel division module is exported for generating different voltage values to analog-to-digital conversion module, receives FPGA output
Channel control signals；As testing resistance interface；
Program-controlled big signal division module is used to DC voltage to be measured be classified to decaying and by the voltage output after decaying to clipping mould
Block receives the gate control signal of FPGA output；As DC voltage interface to be measured；
Clipping module is used to the signal limiter after program-controlled big signal division module decaying be 5V to protect FPGA, and will be after clipping
Signal export to analog-to-digital conversion module；
Virtual value detection module is used to generate corresponding direct current signal according to AC signal to be measured and is transmitted to low-pass filtering module；
As alternating voltage interface to be measured；
Low-pass filtering module, which is used to filter out the AC noise in direct current signal and filtered direct current signal is transmitted to analog-to-digital, to be turned
Change the mold block；
Square wave oscillation module is used to generate the square-wave signal of different frequency according to testing capacitance value and is transmitted to FPGA；As
Testing capacitance interface；
Pure oscillation module is used to generate the sinusoidal signal of different frequency according to inductance value to be measured and is transmitted to Shaping Module；As
Inductive interface to be measured；
Shaping Module is used to that sinusoidal signal to be shaped as to same frequency with the square-wave signal of phase and is transferred to FPGA；
Analog-to-digital conversion module is used to receive d. c. voltage signal, the program-controlled big signal partial pressure that program-controlled multichannel division module generates
Module generates and the clipping d. c. voltage signal through clipping module transmission, the generation of virtual value detection module and low-pass filtered module
The d. c. voltage signal of transmission；D. c. voltage signal is generated into digital signal and is transmitted to FPGA；
LCD touch display screen module is used to generate touch screen control signal according to artificial touch operation and is transmitted to FPGA, receives
The display screen that FPGA is generated, which controls signal and controls signal according to display screen, shows corresponding contents；
The square-wave signal, whole that FPGA is used to receive the digital signal of analog-to-digital conversion module generation, square wave oscillation module generates
The square-wave signal of shape module generation, LCD touch display screen module generate touch screen control signal；It is selected according to touch screen control signal
Select the operating mode of FPGA；It is corresponded to for being calculated in the case where measuring resistance mode according to the digital signal that analog-to-digital conversion module generates
Voltage value simultaneously generates channel control signals and is transmitted to program-controlled multichannel division module, is controlled in the case where measuring resistance mode according to channel
Signal and voltage value, which are calculated resistance value and generate display screen control signal, is transmitted to LCD touch display screen module；For
The digital signal generated under measurement DC voltage mode according to analog-to-digital conversion module calculates corresponding voltage value and generates gating control
Signal is transmitted to program-controlled big voltage module, in the case where measuring DC voltage mode according to gate control signal be calculated
Voltage value, which calculates actual DC voltage value and generates display screen control signal, is transmitted to LCD touch display screen module；For surveying
Range value and the generation of AC signal are directly calculated under amount AC voltage profile according to the digital signal that analog-to-digital conversion module generates
Display screen control signal is transmitted to LCD touch display screen module；For in the case where measuring capacitance mode according to square wave oscillation module
The square-wave signal of generation, which is calculated capacitance and generates display screen control signal, is transmitted to LCD touch display screen module；With
It is calculated in generating again the square-wave signal that shaped module shaping exports according to sine-wave oscillation module in the case where measuring inductive mode
To inductance value and generate display screen control signal be transmitted to LCD touch display screen module.
2. the applicable simple digital multimeter of experimental teaching as described in claim 1, characterized in that FPGA is used
EP4CE0F23C8, program-controlled multichannel division module use REF5025 chip, CD4052B chip and TLV07 chip, virtual value inspection
Wave module uses AD637 chip and OPA842 chip, and low-pass filtering module uses trap, and program-controlled big signal division module uses
Relay HK4100F-DC5V-SHG, clipping module use OPA227 chip, and analog-to-digital conversion module uses ADS1118 chip, square
Shape wave oscillation module uses NE555 chip, and sine-wave oscillation module uses triode 9013, and Shaping Module uses LM311 chip,
LCD touch display screen module uses ALIENTEK ATK-7TFTLCD-V22.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201822042357.2U CN209198519U (en) | 2018-12-06 | 2018-12-06 | A kind of simple digital multimeter that experimental teaching is applicable |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201822042357.2U CN209198519U (en) | 2018-12-06 | 2018-12-06 | A kind of simple digital multimeter that experimental teaching is applicable |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209198519U true CN209198519U (en) | 2019-08-02 |
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ID=67427892
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201822042357.2U Expired - Fee Related CN209198519U (en) | 2018-12-06 | 2018-12-06 | A kind of simple digital multimeter that experimental teaching is applicable |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209198519U (en) |
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2018
- 2018-12-06 CN CN201822042357.2U patent/CN209198519U/en not_active Expired - Fee Related
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Granted publication date: 20190802 Termination date: 20191206 |