CN103884888B - Oscillograph with function of multimeter - Google Patents
Oscillograph with function of multimeter Download PDFInfo
- Publication number
- CN103884888B CN103884888B CN201210557314.2A CN201210557314A CN103884888B CN 103884888 B CN103884888 B CN 103884888B CN 201210557314 A CN201210557314 A CN 201210557314A CN 103884888 B CN103884888 B CN 103884888B
- Authority
- CN
- China
- Prior art keywords
- module
- circuit module
- oscillograph
- control process
- frequency
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Abstract
The invention discloses a kind of oscillograph with function of multimeter, including signal input part, input stage buffering and add circuit module, programmable amplifier module, D/A modular converters, control process module；Also include split-path linear circuit module, the split-path linear circuit module includes a high frequency subtraction amplification circuit module, a coupling unit module, a high-speed ADC modular converter, a low-frequency amplifier circuit module and high-precision low speed ADC modular converters.High-precision universal meter is realized using the improvement of hardware circuit on channel oscilloscope, circuit is simply not take up oscillograph equipment instrument.The present invention can also realize the high-accuracy voltage measurement function, resistance measurement function and break-make drive test amount function of universal meter on oscillograph, while oscillograph can also be made to have isolation features.
Description
Technical field
The present invention relates to electric variable testing field, more particularly to a kind of oscillograph with function of multimeter.
Background technology
In the instrument of electronic surveying basis, universal meter is one of most wide measuring instrument of use range, and on universal meter
Voltage measurement, resistance measurement, logical out of circuit test are most commonly used functions.If one can be increased really on oscillograph
High-precision universal table function, can accurately measure magnitude of voltage, resistance value, test whether short circuit, can so use oscillography
While device, the common function of universal meter is user-friendly, there are very big market prospects.
There is the oscillograph that two classes carry function of multimeter in the market.One kind is hand-held scopememter, hand-held scopememter one
As can increase by the interface and test pencil of two independent universal meters, measured for universal meter.Inside uses an integrated universal meter chip,
To realize function of multimeter, the oscillograph of generally 4 half or lower precision.
Another kind of is on the basis of digital oscilloscope, and universal meter voltage tester function is realized by software.Reference picture 1,
Because the digital oscilloscope of prior art typically uses high-speed ADC, mostly 8 ADC, because ADC only has 8 precision,
So the highest measurement precision that can be realized also only has 28=256, i.e., the maximum voltmeter measurement that can realize 3 half.At present
Software realization mode mainly has two kinds：One kind is that (this is on oscillograph using the calculating of oscillograph screen display data progress voltage
The conventional implementation method of voltage measurement), after being compressed, extracting because display data on the screen is generally ADC sampled datas
Data, it is impossible to really react initial data, cause measurement accuracy to decline, so the measurement accuracy that can be realized is relatively low；It is another
Kind is to carry out voltage measurement calculating using the initial data of ADC samplings, is capable of maximum reservation primary data information (pdi), and can use up can
The raising measurement accuracy of energy, maximum are also merely able to realize the precision of 3 half.
In the prior art, hand-held scopememter needs to increase an independent universal meter circuit module, and circuit is more complicated, instrument
Body product is big, and precision is not also high.And realized using software, limited (general high-speed ADC by oscillograph high-speed sampling ADC digit
For 8), the function of voltmeter that maximal accuracy is 3 half can only be realized.Do not occur also really in oscillograph TCH test channel at present
On realize the oscillograph of High Precision Multimeter.
The content of the invention
The technical problems to be solved by the invention are that asking for High Precision Multimeter can not be realized in prior art oscillograph
Topic, and when prior art realizes universal meter with hardware, independent universal meter circuit module need to be increased, circuit is complicated, instrument body
The problem of product is big.
In order to solve the above technical problems, the present invention provides a kind of oscillograph with function of multimeter, including a signal
Input, an input stage buffering and add circuit module, a programmable amplifier module, a D/A modular converter, one
Control process module；
The signal input part is used to receive an external input signal；
The control process module, for controlling the D/A modular converters to export a bias direct current signal to described defeated
Enter level buffering and add circuit module；
The input stage buffering and add circuit module, for the input signal and the bias direct current signal to be carried out
After add operation, a buffering signals are exported；
The control process module, it is additionally operable to control the programmable amplifier module to carry out gain to the buffering signals
Amplification, export a gain amplified signal；
Characterized in that, also including a split-path linear circuit module, the split-path linear circuit module includes a height
Frequency subtraction amplification circuit module, a coupling unit module, a high-speed ADC modular converter, a low-frequency amplifier circuit module
With high-precision low speed ADC modular converters；
The low-frequency amplifier circuit module, for being filtered to the gain amplified signal, export a low-frequency gain
Amplified signal；
The high frequency subtraction amplification circuit module, for the gain amplified signal to be subtracted into the low-frequency gain amplification letter
Number output one high-frequency gain amplified signal；
The coupling unit module, for carrying out high-pass filtering to the high-frequency gain amplified signal, export a high pass
Gain amplified signal；
The high-speed ADC modular converter, for being sampled to the high pass gain amplified signal, and by the height after sampling
Fast sampled data inputs control process module；
The low speed ADC modular converters, for being sampled to the low-frequency gain amplified signal, and will be low after sampling
Fast sampled data inputs control process module；
The control process module, it is additionally operable to the high-speed sample data and the low speed sampled data being summed into n positions
Data, n is more than 8 and is less than or equal to 24, and n-bit data is carried out into mean value calculation or virtual value calculating, and result of calculation is carried out
Display.
As one kind illustrate, the control process module include a delay adjustment module, an interpolating module, one by
Point summation module, a sampling control module, a function of voltmeter module, the delay adjustment module, for the height
Fast sampled data enters line delay, the high-speed sample data after output delay；The interpolating module, for the low speed hits
According to interpolation arithmetic is carried out, the low speed sampled data after interpolation is obtained, the point-by-point summation module, for by the height after the delay
Fast sampled data is added with the low speed sampled data after the interpolation, generates 24 data, and the sampling control module is used to control
The sampling of oscillograph processed, data after sampling are stored, are shown, the function of voltmeter module, for 24 data to be entered
Row mean value calculation or virtual value are calculated, and result of calculation is shown.
Illustrated as one kind, the coupling unit module is formed using RC high-pass filtering circuits.
As one kind illustrate, be also linked in sequence between the signal input part and the control process module one it is controllable
Switch and a programmable current source module, the control process module be additionally operable to control respectively the gate-controlled switch break-make and
The electric current gear selection of programmable current source module.
To be illustrated as one kind, the coupling unit module is formed using transformer, and when the coupling unit module uses
During transformer, first digital isolator is connected between the low speed ADC and the control process module, described
Second digital isolator is connected between programmable amplifier module and the control process module, in the D/A moduluss of conversion
The 3rd digital isolator is connected between block and the control process module.
As one kind illustrate, be also linked in sequence between the signal input part and the control process module one it is controllable
Switch and a programmable current source module and the 4th digital isolator, the control process module are additionally operable to by described
4th digital isolator controls the break-make of the gate-controlled switch and the electric current gear selection of programmable current source module respectively.
Illustrated as one kind, the split-path linear circuit module also includes a buffer circuit module, the buffer circuit
Module is connected between the coupling unit module and the high-speed ADC modular converter, for strengthening the high pass gain amplification
Signal, to drive the high-speed ADC modular converter.
The beneficial effects of the present invention are：On channel oscilloscope high-precision ten thousand are realized using the improvement of hardware circuit
With table, circuit is simply not take up oscillograph equipment instrument.
Brief description of the drawings
Fig. 1 is the structural representation of prior art oscillograph
Fig. 2 is a kind of structural representation of the oscillograph preferred embodiment 1 with function of multimeter of the present invention
Fig. 3 is the internal structure schematic diagram of split-path linear circuit module 204 in the preferred embodiment of the present invention 1
Fig. 4 is another distressed structure schematic diagram of control process module 205 in the preferred embodiment of the present invention 1
Fig. 5 is the internal circuit schematic diagram of split-path linear circuit module 204 in the preferred embodiment of the present invention 1
Fig. 6 is a kind of structural representation of the oscillograph preferred embodiment 2 with function of multimeter of the present invention
Fig. 7 is the preferred embodiment of the present invention the 2nd kind of distressed structure schematic diagram of 1 split-path linear circuit module 204
The structure chart of 2044 form of Fig. 8 (A) low-frequency amplifier circuit modules 1；
The structure chart of 2044 form of Fig. 8 (B) low-frequency amplifier circuit modules 2；
The structure chart of 2044 form of Fig. 8 (C) low-frequency amplifier circuit modules 3；
The structure chart of 2044 form of Fig. 8 (D) low-frequency amplifier circuit modules 4；
Fig. 9 is the preferred embodiment of the present invention the 3rd kind of distressed structure schematic diagram of 1 split-path linear circuit module 204
Figure 10 is the preferred embodiment of the present invention the 4th kind of distressed structure schematic diagram of 1 split-path linear circuit module 204
Figure 11 be in the 4th kind of distressed structure of split-path linear circuit module 204 low-frequency amplifier circuit module 2044 another
Distressed structure figure
Figure 12 is that Fig. 6 is a kind of structural representation of the oscillograph preferred embodiment 3 with function of multimeter of the present invention
Embodiment
Below in conjunction with the accompanying drawings and preferred embodiment is described in detail to the present invention.
Embodiment 1, with reference to reference picture 2 and Fig. 3, oscillograph 200 includes signal input part 201, input stage buffering and addition
Circuit module 202, programmable amplifier module 203, D/A modular converters 206, control process module 205；Signal input part 201
Receive an external input signal；Control process module 205, control D/A modular converters 206 export a bias direct current signal extremely
Input stage buffers and add circuit module 202；Input stage buffer and add circuit module 202, by the input signal with it is described
After bias direct current signal carries out add operation, a buffering signals are exported；The programmable amplification of control process module 205, also control
Device module 203 carries out gain amplification to the buffering signals, exports a gain amplified signal；Oscillograph 200 also includes one
Split-path linear circuit module 204, split-path linear circuit module 204 include high frequency subtraction amplification circuit module 2041, coupling unit
Module 2042, high-speed ADC modular converter 2043, low-frequency amplifier circuit module 2044 and high-precision low speed ADC modular converters 2045；
Low-frequency amplifier circuit module 2044, the gain amplified signal is filtered, exports a low-frequency gain amplified signal；High frequency
Subtraction amplification circuit module 2041, the gain amplified signal is subtracted into the low-frequency gain amplified signal and exports a high frequency increasing
Beneficial amplified signal；Coupling unit module 2042, high-pass filtering is carried out to the high-frequency gain amplified signal, export a high pass and increase
Beneficial amplified signal；The high-pass filtering, refer to use AC coupled mode, high-speed ADC modular converter 2043 will be ac-coupled to
Input；High-speed ADC modular converter 2043, the high pass gain amplified signal is sampled, and the high speed after sampling is adopted
Sample data input control process module 205；Low speed ADC modular converters 2045, the low-frequency gain amplified signal is sampled,
And the low speed sampled data after sampling is inputted into control process module 205；Control process module 205, by the high-speed sampling number
24 data are summed into according to the low speed sampled data, and 24 data are subjected to mean value calculation or virtual value calculating, it is complete
Into the function of universal meter combined-voltage measurement.Mean value calculation is carried out to 24 data, this is universal meter DC voltage
Function；Virtual value calculating is carried out to 24 data, this is universal meter alternating voltage function.During concrete application function of multimeter,
The menu of universal meter measurement can be increased in oscilloscope display interface, to call function of multimeter, and carried out on display interface
The display of universal meter measurement result.When carrying out universal meter measurement, oscilloprobe can be connected to oscillograph input BNC
On, circuit-under-test is then connected, is measured, now with 1:1 probe precision can be higher.Better way is connected using adapter
It is connected on oscillograph input BNC, then pen meter of universal meter is connected on adapter, then measures.
The preferred embodiment of the present invention 1 passes through the gain amplified signal as a result of split-path linear circuit module 204
Path divide into low frequency channel and high frequency channel, low frequency channel is sampled using high-precision low speed ADC modular converters, made low
The data of frequency path are provided with the required precision of high-accuracy voltage table.And if without split-path linear circuit module 204, only use
A high-speed ADC as shown in prior art figure 1 is sampled, because sampling resolution and sampling rate are contradiction, to realize
Oscillograph bandwidth, the leading indicator of sample rate, the ADC (such as 24) of high sampling resolution cannot be selected, so as to realize pair
The sampling with high precision of signal.The addition of split-path linear circuit module 204, effectively solves the band of high-speed ADC in the prior art
The contradiction of wide, sample rate and precision, high bandwidth, sample rate and high accuracy can be realized simultaneously (just for direct current and low frequency signal)
Sampling.For the different demands of oscillograph and universal meter, (oscillograph is observation instrument, and major demands are high sampling rate, high band
It is wide；Universal meter is measuring instrument, it is desirable to be high accuracy), input signal is divided into two parts, realizes oscillograph and general-purpose respectively
The demand of table.
The High Precision Multimeter that the preferred embodiment of the present invention 1 is realized, utilizes oscilloscope analog input terminal, it is not necessary to increase
Extra pen meter of universal meter input, using further facilitating.The high-accuracy voltage table that the preferred embodiment of the present invention 1 is realized, no
The sample rate of oscillograph is influenceed, oscilloscope sampling rate is determined by high-speed ADC modular converter.
In order to preferably reach the function that High Precision Multimeter is realized in oscillograph, reference picture 4, the present invention is preferable to carry out
One kind of example 1 deforms：Control process module 205 includes an interpolating module 2052, one of delay adjustment module 2051, one
2053, sampling control modules 2055 of point-by-point summation module, a function of voltmeter module 2054, delay adjustment module
2051, for entering line delay to the high-speed sample data, the delay of low frequency low speed path is compensated, the high speed after output delay is adopted
Sample data；Interpolating module 2052, interpolation arithmetic is carried out to the low speed sampled data, make low speed data points and high-speed data point
Number is equal, obtains the low speed sampled data after interpolation, point-by-point summation module 2053, by the high-speed sample data after the delay and
Low speed sampled data after the interpolation is added point by point, generates 24 data, and 24 data after addition are sent into controlling of sampling mould
Block 2055, the functions such as the sampling, storage, display of oscillograph are completed, function of voltmeter module 2054,24 data are averaged
Value calculates or virtual value calculates.Mean value calculation is carried out to 24 data, this is universal meter DC voltage function；To 24 digits
According to virtual value calculating is carried out, this is universal meter alternating voltage function.Control process module 205 is due to further employing delay
Adjustment module 2051, interpolating module 2052, point-by-point summation module 2053, therefore can ensure what point-by-point summation module 2053 exported
Data are 24 data, it is ensured that higher general-purpose meter accuracy.
Illustrated as one kind, when not being delayed between low speed sampled data and high-speed sample data, control process module 205
Can there is no delay adjustment module 2051, output also can guarantee that 24 data.
Reference picture 5, is the internal circuit schematic diagram of split-path linear circuit module 204 in the preferred embodiment of the present invention 1, branch
Linear circuit module 204 also includes a buffer circuit module 2046, and buffer circuit module 2046 is connected to coupling unit module
Between 2042 and high-speed ADC modular converter 2043, for strengthening the high pass gain amplified signal, to drive high-speed ADC to change
Module 2043.Coupling unit module 2042 is formed using RC high-pass filtering circuits, carries out high-frequency coupling, isolates low frequency, high pass
Cut-off frequency determines by C2 and R6, this cut-off frequency need it is lower than the low cut-off frequency of high frequency subtraction amplification circuit module 2041,
The gain amplified signal is subtracted the low-frequency gain amplified signal and exports a height by high frequency subtraction amplification circuit module 2041
Frequency gain amplified signal, the frequency response curve of the high-frequency gain amplified signal are a band logical frequency response curves, band logical frequency response curve
There is a cut-off frequency in low-frequency range, this cut-off frequency is defined as low cut-off frequency；Can be by high frequency subtraction amplification circuit
All frequency contents of the output signal of module 2041 are coupled to buffer circuit module 2046.Split-path linear circuit module 204 its
He will describe in detail at circuit module again in the embodiment below.
Illustrated as one kind, can if the output of coupling unit module 2042 can drive high-speed ADC modular converter 2043
With no buffer circuit module 2046.
Reference picture 6, oscillograph 300 also include a gate-controlled switch 301 and a programmable current source module 302, control
Processing module 205 controls the break-make of gate-controlled switch 301 and the electric current gear selection of programmable current source module 302 respectively.And then
Realize the resistance measurement of more gears, logical out of circuit test.When user selects resistance measurement function, control process module 205 controls
Gate-controlled switch 301 closes, and programmable current source module 302 is connected into oscilloscope signal input 201, according to different resistance
Measure gear to set, carry out the setting of programmable current source.When measured resistance is connected to oscilloscope signal input 201, electricity
Stream I flows through measured resistance, forms voltage.Then divided by electric current I by the high-precision voltage measurement of oscillograph, that is, resistance is obtained
Value.
It is measured resistance and 1M Ω parallel connection during measurement because the input resistance of oscillograph is 1M Ω.Therefore, when tested electricity
Resistance<During=10k Ω, its error very little, less than 1%.When measured resistance is bigger, measurement error is bigger.Break-make drive test amount is actual
It is one kind of resistance measurement, when test to resistance value is close to 0 Ω, prompts short circuit.Diode polarity measures, and resistance measurement
One kind, during diode reverse, resistance is very big.When diode forward turns on, resistance very little, such as silicone tube, forward voltage drop approach
0.7V, utilize resistance and voltage measurement, it is possible to judge diode polarity.
Illustrated as one kind, between oscilloscope signal input 201 and input stage buffering and add circuit module 202 also
Connect a decay switching module, decay switching module controls decay selection by control process module, can select it is straight-through or
Decay output, is mainly used in oscillograph in big vertical sensitivity gear, signal is first decayed, then inputs electricity below
Lu Zhong, otherwise input signal amplitude is excessive, makes subsequent conditioning circuit saturation, can not effectively be worked；And in the small vertical spirit of oscillograph
During sensitivity gear, because signal amplitude is little, attenuation network selection is straight-through, and signal is directly connected into subsequent conditioning circuit.Attenuation network
Network is typically made up of resistance, electric capacity, in the range of oscillograph whole bandwidth, has flatter amplitude-frequency response.
Reference picture 7, it is the preferred embodiment of the present invention the 2nd kind of distressed structure schematic diagram of 1 split-path linear circuit module 204, its
Middle coupling unit module 2042 is formed using transformer, and transformer plays a part of high-frequency isolation herein, and works as coupling unit mould
When block 2042 is using transformer, one first numeral is connected between low speed ADC 2045 and the control process module 205
Isolator 2047, the first digital isolator play a part of low frequency isolation herein.Coupling unit in split-path linear circuit module 204
Module 2042 is formed using transformer, while adds the first digital isolator 2047, it is possible to achieve has function of voltmeter
Isolate oscillograph.
In this distressed structure embodiment, the circuit form of low-frequency amplifier circuit module 2044 can have following 4 kinds of forms：
Such as Fig. 8 (A), form 1 follows circuit, and circuit bandwidth is determined in itself by amplifier.
As Fig. 8 (B), form 2, low pass follow circuit, circuit bandwidth is determined by R1, C1 and amplifier bandwidth.
Such as Fig. 8 (C), form 3, first RC low passes, then amplifier follow, circuit bandwidth has R, C and amplifier bandwidth to determine.
As Fig. 8 (D), form 4, an active step low-pass amplifier, circuit bandwidth have R1, C1, R2, C2 and amplifier band
Width determines.
Certain low-frequency amplifier circuit module 2044 can also use the side of such as casacade multi-amplifier or low pass filter cascade
Formula, other known active low-pass filter circuit forms can also be used, have no effect on the creativeness of the present invention.
The preferred low bandwidth high-precision amplifyings of amplifier U1 in low-frequency amplifier circuit module 2044, amplifier U1 can be selected
With any high-precision amplifying, to meet the requirement to low-frequency sampling precision, naturally it is also possible to from precision, low noise, low mistake
Very, these more excellent amplifiers of Low-bias Current, Low Drift Temperature, can be advantageous to the realization to low frequency high precision technology effect.Example
Such as select AD823, AD8639 of ADI companies.
The circuit form of high frequency subtraction amplification circuit module 2041 is scaling circuit, because low frequency path gain is 1,
So R2=R3=R4=R5, the gain of high-frequency path is also 1.Assuming that signal input is Vin, the output of low-frequency amplifier circuit module
For Vlf, then U2 exports Uhf=Vin-Vlf.
Amplifier U2 in high frequency subtraction amplification circuit module 2041 can select any high speed amplifier, as long as can expire
The maximum bandwidth and maximum voltage amplitude that foot design needs.Certainly, can from bigger bandwidth, low noise, low distortion amplifier
It is advantageously implemented design bandwidth demand.Such as AD8038, AD8012 of ADI companies etc..
Low speed ADC 2045 in this distressed structure embodiment employs sigma-delta ADC (also known as Delta-Sigma modulation
Analog-digital converter), optimal case is the ADC using 24bit, higher measurement accuracy can be realized, such as ADI companies
AD7763, it is 24bit, 625kHz sample rate, the sigma-delta ADC of 109dB dynamic ranges.AD7763 outputs are SPI interface, it is necessary to 3
The isolation to sampled digital signal is realized in railway digital isolation.
Illustrated as one kind, when coupling unit module 2042 is using RC high-pass filtering circuits, AD77763 output is simultaneously
Also without digital isolator isolate.
Low speed ADC 2045 and digital isolator suboptimal design in this distressed structure embodiment, it is to use ADI companies
Band isolation analog-digital converter AD7401A.It is 16 sigma-delta modulators of an isolation, can realize 5000Vrms, hold
The isolating power of continuous 1 minute time.It converts the input into the 1bit data flows of high speed, then by internal transformer every
From the clock MCLKIN of one 20MHz frequency of input, as the sampling clock of modulator, output 1bit data MDAT.So,
A device is only needed, is achieved that the function of sigma-delta ADC and digital isolator, it is simple on circuit structure.
Certainly, using AD7401A, it is necessary to low frequency path is signally attached into its input VIN+, by the ground of Measurement channel
It is connected on VIN-.
Coupling unit module 2042 in this distressed structure embodiment uses transformer, in order to realize the band of design requirement
Width, the maximum operating frequency of transformer needs the bandwidth more than design requirement, and the lowest operating frequency of transformer needs to prolong
Reach and be less than 10kHz, lowest operating frequency is extended to less than 10kHz, in order that having necessarily with the working frequency of low frequency path
It is overlapping, the output of such low frequency and high-frequency path, which is added, could reflect input signal.And pressure-resistant between primary and secondary will meet to set
Meter it is expected.Transformer winding mode employs line transformer mode in the present embodiment, it is possible to achieve preferable frequency response.
The transformer of other forms can also, but frequency response response it is slightly worse.
Magnetic core of transformer most preferably uses high permeability soft magnetic ferrite bead, such as Beijing QiXing flying Electronics Co., Ltd
R10K series, such as R10K-H13x7x5.Such as the A10 series of Yue Feng electronic materials limited company, such as A10-T12x6x4.
Wire rod uses three layer insulation wire, it is possible to achieve very high is pressure-resistant, such as electronics industry Co., Ltd. of Furukawa Electronic
TEX-E three layer insulation wires, line footpath Ф 0.20mm.Such as the TIW-B directly weldering type three layer insulation wires along positive electron Co., Ltd, line footpath Ф
0.20mm。
The line transformer of this distressed structure embodiment can realize minimum 1kHz, highest 200MHz working frequency,
Amplitude-frequency response fluctuates very little in frequency band range.
R6 is the load resistance of transformer secondary side in buffer circuit module 2046 in this distressed structure embodiment, for adjusting
Save the amplitude-frequency response of transformer.Selected value is 1.2k Ω.Amplifier U3 selects Differential OPAMP, to adapt to the second analog-digital converter
Differential Input requirement, from the LMH6554 of TI companies, input, feedback resistance R7=R8=R9=R10=300 Ω.
Illustrated as one kind, buffer circuit module 2046 can not also be used in this distressed structure embodiment.
ADC modular converters 2043 in this distressed structure embodiment, any satisfaction can be selected to design sample rate requirement
ADC.Such as select 8 1Gsa/s of TI companies ADC, model ADC08D1000.As from 8 1Gsa/s of E2V companies
ADC, model AT84AD001B.
Reference picture 9, is the preferred embodiment of the present invention the 3rd kind of distressed structure schematic diagram of 1 split-path linear circuit module 204, Fig. 9
The difference of shown the 3rd kind of distressed structure and the 2nd kind of distressed structure shown in Fig. 7 is that transformer T1 driving and reception are all adopted
Use differential mode.Then the amplifier of high frequency subtraction amplification circuit module 2041 selects fully-differential amplifier, and amplifier output is poor
Sub-signal, the both ends of transformer T1 primary sides are connected to, for driving transformer.The gain amplified signal and the low-frequency gain
Amplified signal is connected to two inputs of differential amplifier circuit, forms subtraction circuit.Resistance value R2=R3=R4=R5=300
Ω。
Reference picture 10, it is the preferred embodiment of the present invention the 4th kind of distressed structure schematic diagram of 1 split-path linear circuit module 204, this
Distressed structure embodiment provides a kind of split-path linear circuit for differential signal input.Signal input is differential signal, low
Frequency amplification circuit module 2044 also uses fully differential amplifying circuit, and its bandwidth can be selected according to the requirement of low frequency path, also may be used
To increase extra low-pass filter circuit, to ensure that the bandwidth of low frequency path meets that the signal of low speed ADC modular converters 2045 is defeated
Enter requirement.Such as the fully-differential amplifier AD8476 of ADI companies.Reference picture 11, low-frequency amplifier circuit module 2044 can also use
Two single-ended amplifiers, the P to differential input signal, N-terminal progress low frequency amplification, amplifier type selecting are same as above respectively.High frequency subtraction
The difference of the 3rd kind of distressed structure shown in amplification circuit module 2041 and Fig. 9 is that fully-differential amplifier constitutes ratio fortune
Circuit is calculated, resistance selection R1, R2, R3, R4, R5, R6 is equal, is 300 Ω.So U1 output is exactly input signal and low frequency
Amplifying circuit output is subtracted each other.
Reference picture 12, in oscillograph 400, due to employing transformer and numeral isolation in split-path linear circuit module 204
Device (physical circuit can combine reference picture 7, Fig. 9 and Figure 10), therefore in programmable amplifier module 203 and control process module
Second digital isolator is connected between 205, one the is connected between D/A modular converters 206 and control process module 205
Three digital isolators 402.Also be linked in sequence a gate-controlled switch 301 between signal input part 201 and control process module 205
With a programmable current source module 302 and the 4th digital isolator 403, control process module 205 passes through the 4th numeral
Isolator 403 controls the break-make of gate-controlled switch 301 and the electric current gear selection of programmable current source module 302 respectively.It is and then real
The now resistance measurement of more gears, logical out of circuit test.When user selects resistance measurement function, the control of control process module 205 can
The closure of control switch 301, is connected to oscilloscope signal input 201 by programmable current source module 302, is surveyed according to different resistance
Measure gear to set, carry out the setting of programmable current source.When measured resistance is connected to oscilloscope signal input 201, circuit I
Measured resistance is flowed through, forms voltage.Then divided by electric current I by the high-precision voltage measurement of oscillograph, that is, resistance value is obtained.
It is measured resistance and 1M Ω parallel connection during measurement because the input resistance of oscillograph is 1M Ω.Therefore, measured resistance is worked as<=10k
During Ω, its error very little, less than 1%.When measured resistance is bigger, measurement error is bigger.
Break-make drive test amount, really one kind of resistance measurement, when test to resistance value is close to 0 Ω, prompt short circuit.Two poles
Pipe polarity measurement, and one kind of resistance measurement, during diode reverse, resistance is very big.When diode forward turns on, resistance is very
Small, such as silicone tube, forward voltage drop utilizes resistance and voltage measurement close to 0.7V, it is possible to judges diode polarity.
A decay is also connected between oscilloscope signal input 201 and input stage buffering and add circuit module 202
Handover module, decay switching module control decay selection by control process module, can select the straight-through or output that decays, mainly
For oscillograph in big vertical sensitivity gear, signal is first decayed, then inputs in circuit below, otherwise inputs
Signal amplitude is excessive, makes subsequent conditioning circuit saturation, can not effectively be worked；And in the small vertical sensitivity gear of oscillograph, by
Little in signal amplitude, attenuation network selection is straight-through, and signal is directly connected into subsequent conditioning circuit.Attenuation network typically by resistance,
Electric capacity is formed, and in the range of oscillograph whole bandwidth, has flatter amplitude-frequency response.
Illustrated as one kind, decay switching module 404 can be not connected in the present embodiment, still can be real on oscillograph
High-accuracy voltage measurement function, resistance measurement function and the break-make drive test amount function of existing universal meter, at the same oscillograph also have every
From function.Isolation features are exactly that the electric signal of oscillograph input side is delivered into outlet side, but between input side and outlet side
It is electrically isolation, adds the safety in utilization of oscillograph.
Illustrated as one kind, gate-controlled switch 301, programmable current source module 302 and the can be not connected in the present embodiment
Four digital isolators 403, the high-accuracy voltage measurement function of universal meter still can be realized on oscillograph, while oscillograph is also
With isolation features.
Illustrated as one kind, control process module is realized using FPGA in the present embodiment.
Above-described is only the preferred embodiments of the present invention, should be understood that the explanation of preferred embodiment above only
It is the method and its core concept for being used to help understand the present invention, the protection domain being not intended to limit the present invention is all in this hair
Any modification for being made within bright thought and principle, equivalent substitution etc., should be included in the scope of the protection.
Claims (9)
1. a kind of oscillograph with function of multimeter, including a signal input part, an input stage buffering and add circuit
Module, a programmable amplifier module, a D/A modular converter, a control process module；The signal input part is used for
Receive an external input signal；
The control process module, for controlling the D/A modular converters to export a bias direct current signal to the input stage
Buffering and add circuit module；
The input stage buffering and add circuit module, for the input signal and the bias direct current signal to be carried out into addition
After computing, a buffering signals are exported；
The control process module, it is additionally operable to control the programmable amplifier module to put buffering signals progress gain
Greatly, a gain amplified signal is exported；
Characterized in that, also including a split-path linear circuit module, the split-path linear circuit module subtracts including a high frequency
Method amplification circuit module, a coupling unit module, a high-speed ADC modular converter, a low-frequency amplifier circuit module and height
Precision low speed ADC modular converters；
The low-frequency amplifier circuit module, for being filtered to the gain amplified signal, export a low-frequency gain amplification
Signal；
The high frequency subtraction amplification circuit module, it is defeated for the gain amplified signal to be subtracted into the low-frequency gain amplified signal
Go out a high-frequency gain amplified signal；
The coupling unit module, for carrying out high-pass filtering to the high-frequency gain amplified signal, export a high pass gain
Amplified signal；
The high-speed ADC modular converter, for being sampled to the high pass gain amplified signal, and the high speed after sampling is adopted
Sample data input control process module；
The low speed ADC modular converters, for being sampled to the low-frequency gain amplified signal, and the low speed after sampling is adopted
Sample data input control process module；
The control process module, it is additionally operable to the high-speed sample data and the low speed sampled data being summed into n-bit data,
N is more than 8 and is less than or equal to 24, and n-bit data is carried out into mean value calculation or virtual value calculating, and result of calculation is shown.
2. oscillograph according to claim 1, it is characterised in that the control process module includes a delay adjustment mould
Block, an interpolating module, point-by-point summation module, a sampling control module, a function of voltmeter module, the delay
Adjustment module, for entering line delay, the high-speed sample data after output delay to the high-speed sample data；The interpolation mould
Block, for carrying out interpolation arithmetic to the low speed sampled data, obtain the low speed sampled data after interpolation, the point-by-point addition mould
Block, for the high-speed sample data after the delay to be added with the low speed sampled data after the interpolation, 24 data are generated,
The sampling control module is used to control the sampling of oscillograph, data after sampling is stored, shown, the function of voltmeter
Module, for 24 data to be carried out into mean value calculation or virtual value calculating, and result of calculation is shown.
3. oscillograph according to claim 1, it is characterised in that the coupling unit module uses RC high-pass filtering circuits
Form.
4. according to the oscillograph described in claim 1,2 or 3, it is characterised in that at the signal input part and the control
Also be linked in sequence a gate-controlled switch and a programmable current source module between reason module, and the control process module is additionally operable to
The break-make of the gate-controlled switch and the electric current gear selection of programmable current source module are controlled respectively.
5. oscillograph according to claim 1 or 2, it is characterised in that the coupling unit module is formed using transformer,
And when the coupling unit module uses transformer, between the low speed ADC modular converters and the control process module
First digital isolator is connected, one the is connected between the programmable amplifier module and the control process module
Two digital isolators, the 3rd digital isolator is connected between the D/A modular converters and the control process module.
6. oscillograph according to claim 5, it is characterised in that in the signal input part and the control process module
Between be also linked in sequence a gate-controlled switch and a programmable current source module and the 4th digital isolator, the control
Processing module is additionally operable to control the break-make and programmable current source of the gate-controlled switch respectively by the 4th digital isolator
The electric current gear selection of module.
7. oscillograph according to claim 1 or 2, it is characterised in that the split-path linear circuit module also includes one
Buffer circuit module, the buffer circuit module are connected between the coupling unit module and the high-speed ADC modular converter,
For strengthening the high pass gain amplified signal, to drive the high-speed ADC modular converter.
8. oscillograph according to claim 4, it is characterised in that the split-path linear circuit module also includes a buffering
Circuit module, the buffer circuit module are connected between the coupling unit module and the high-speed ADC modular converter, are used for
Strengthen the high pass gain amplified signal, to drive the high-speed ADC modular converter.
9. oscillograph according to claim 6, it is characterised in that the split-path linear circuit module also includes a buffering
Circuit module, the buffer circuit module are connected between the coupling unit module and the high-speed ADC modular converter, are used for
Strengthen the high pass gain amplified signal, to drive the high-speed ADC modular converter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210557314.2A CN103884888B (en) | 2012-12-20 | 2012-12-20 | Oscillograph with function of multimeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210557314.2A CN103884888B (en) | 2012-12-20 | 2012-12-20 | Oscillograph with function of multimeter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103884888A CN103884888A (en) | 2014-06-25 |
| CN103884888B true CN103884888B (en) | 2018-03-16 |
Family
ID=50953894
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210557314.2A Active CN103884888B (en) | 2012-12-20 | 2012-12-20 | Oscillograph with function of multimeter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103884888B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104280601B (en) * | 2014-09-27 | 2018-05-15 | 无锡市恒通智能交通设施有限公司 | A kind of voltage measurement system of Vehicular intelligent monitoring photo-voltaic power supply |
| CN105116362B (en) * | 2015-08-26 | 2017-10-31 | 电子科技大学 | A kind of oscilloscope analog front end impedance inverter circuit with program control calibration function |
| CN107919942A (en) * | 2016-10-10 | 2018-04-17 | 深圳超级数据链技术有限公司 | A kind of signal sampling restoration methods and device |
| CN106568996B (en) * | 2016-11-17 | 2019-03-05 | 中国电子科技集团公司第四十一研究所 | A kind of efficient low distortion digital oscilloscope training signal generating circuit and method |
| CN108572272A (en) * | 2017-12-26 | 2018-09-25 | 深圳市鼎阳科技有限公司 | A kind of method and multimeter improving multimeter measurement accuracy |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6297827B1 (en) * | 1998-02-23 | 2001-10-02 | Iwatsu Electric Co., Ltd. | Wave-form observation apparatus |
| CN1963538A (en) * | 2006-11-21 | 2007-05-16 | 李君� | Shunt circuit linearity insulating circuit apparatus |
| CN101701973A (en) * | 2009-11-18 | 2010-05-05 | 北京普源精电科技有限公司 | Data acquisition device and method thereof |
| CN102466750A (en) * | 2010-11-03 | 2012-05-23 | 北京普源精电科技有限公司 | Circuit and method for measuring alternating current of digital universal meter |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6911827B2 (en) * | 2002-10-21 | 2005-06-28 | Hewlett-Packard Development Company, L.P. | System and method of measuring low impedances |
| JP4759351B2 (en) * | 2004-09-17 | 2011-08-31 | 株式会社リコー | Evaluation device and evaluation system |
-
2012
- 2012-12-20 CN CN201210557314.2A patent/CN103884888B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6297827B1 (en) * | 1998-02-23 | 2001-10-02 | Iwatsu Electric Co., Ltd. | Wave-form observation apparatus |
| CN1963538A (en) * | 2006-11-21 | 2007-05-16 | 李君� | Shunt circuit linearity insulating circuit apparatus |
| CN101701973A (en) * | 2009-11-18 | 2010-05-05 | 北京普源精电科技有限公司 | Data acquisition device and method thereof |
| CN102466750A (en) * | 2010-11-03 | 2012-05-23 | 北京普源精电科技有限公司 | Circuit and method for measuring alternating current of digital universal meter |
Non-Patent Citations (2)
| Title |
|---|
| 双通道宽带隔离放大器的设计;王礼平;《电测与仪表》;20041231;第41卷(第462期);第51-54页 * |
| 基于FPGA的数字存储示波表;冯国楠等;《河北工业科技》;20101130;第27卷(第6期);第489-491、496页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103884888A (en) | 2014-06-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103884888B (en) | Oscillograph with function of multimeter | |
| CN103884893B (en) | A kind of shunt circuit linearity insulating circuit and its oscillograph | |
| CN104360165A (en) | Multichannel resistance measuring device | |
| Drung et al. | Ultralow-noise chopper amplifier with low input charge injection | |
| CN105245194B (en) | Two-phase lock-in amplifier based on DSP and LabVIEW | |
| CN109782054B (en) | Alternating voltage commutation differential measurement device and method based on quantum voltage | |
| CN101839931A (en) | Alternating current signal measurement device, system and method | |
| CN102707153A (en) | Contact resistance measuring system and method based on voltage-frequency conversion method | |
| CN111880052A (en) | Hand-held type partial discharge detection device based on bluetooth interconnection terminal cluster | |
| CN117147955B (en) | Voltage measurement circuit and method | |
| CN102445608A (en) | Monitoring device and calibration method for electric energy quality | |
| CN102129032B (en) | Transformer on-load tapping switch tester | |
| WO2023231578A1 (en) | Analog quantity acquisition method and device | |
| CN101285852B (en) | Alternating current voltage electric current converter and device and method for testing alternating-current small ammeter | |
| CN201788222U (en) | AC-DC (alternating current-direct current) compatible isolated voltage sampling circuit | |
| CN204287286U (en) | A kind of optical fiber control circuit in conjunction with low-power consumption photoelectric switching circuit | |
| CN204314388U (en) | A kind of program controlled high precision resistance measuring instrument based on analog to digital converter | |
| CN207164134U (en) | A kind of Portable direct-current large-current table | |
| CN113884963A (en) | High-precision direct-current standard electric energy meter | |
| CN210626547U (en) | Measuring device | |
| CN103575975A (en) | Constant-90-degree phase shift type reactive power measurement circuit | |
| CN104122454B (en) | A kind of soft magnetic materials loss measurement system and method | |
| CN203054063U (en) | Input voltage measuring circuit for high-voltage frequency converter | |
| CN106353699A (en) | Digital integration type flux meter | |
| CN219609077U (en) | Dielectric loss measuring device of high-voltage capacitive equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |