CN109239443A - A kind of the true rms measurement method and circuit of random waveform - Google Patents
A kind of the true rms measurement method and circuit of random waveform Download PDFInfo
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- CN109239443A CN109239443A CN201810847638.7A CN201810847638A CN109239443A CN 109239443 A CN109239443 A CN 109239443A CN 201810847638 A CN201810847638 A CN 201810847638A CN 109239443 A CN109239443 A CN 109239443A
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- resistance
- virtual value
- voltage signal
- direct current
- value
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/02—Measuring effective values, i.e. root-mean-square values
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- General Physics & Mathematics (AREA)
- Measurement Of Current Or Voltage (AREA)
Abstract
The invention discloses the true rms measurement methods and circuit of a kind of random waveform.Process are as follows: the instantaneous voltage signal for obtaining random waveform is decayed to instantaneous voltage signal, is filtered；To treated, signal is sampled, calculation processing obtains virtual value, and virtual value is switched to d. c. voltage signal；D. c. voltage signal is become into corresponding digital signal by analog-to-digital conversion；Digital signal is carried out according to attenuation coefficient to be converted to actual real available value.The present invention will be averaged after its square by acquiring the instantaneous value of waveform voltage to be measured according to the mathematical definition of virtual value, then calculate its square root again, obtain its virtual value.This measurement method must be defined according to virtual value completely, not required the shape of waveform, measurement method is simple and effective, versatile.
Description
Technical field
The invention belongs to effective value measurement technical fields, and in particular to a kind of true rms measurement method of random waveform and
Circuit.
Background technique
For alternating current, voltage is the waveform of a variation, and the voltage value that usually we describe it refers to its virtual value,
220V power supply as described in us, crest voltage 311.2V, peak-to-peak value 622.4V.
Virtual value is by fever (power) come what is defined: heat that a certain alternating current is generated by resistor and another straight
The heat that galvanic electricity is generated in the same time by the resistor is equal, then the DC voltage value i.e. alternating current voltage thus
Virtual value.Its mathematical definition are as follows:Wherein VrmsIt is virtual value, T is measurement duration, V
(t) it is instantaneous voltage, has functional relation with the time but not necessarily have periodicity.
In general measuring instrument, it is difficult to realize that virtual value is measured by generating heat, so in most of voltages
In measuring instrument, measurement method is not " fever " that defines by virtual value come what is measured.Existing one kind multimeter
Be generally reference with sine wave, between the virtual value for being 2 times of radical sign by the peak value of sine wave relationship come obtain virtual value (or
Derived by average value), the alternating voltage that virtual value is only applicable to sinusoidal waveform class is obtained with such method, is not suitable for it
The waveform of its shape.
Summary of the invention
The object of the invention is to provide a kind of really having for random waveform to solve deficiency existing for above-mentioned background technique
Valid value measurement method and circuit do not require the shape of waveform, versatile.
The technical solution adopted by the present invention is that: a kind of true rms measurement method of random waveform, comprising the following steps:
Step 1, the instantaneous voltage signal for obtaining random waveform is decayed to instantaneous voltage signal, is filtered；
Step 2, to treated, signal is sampled, calculation processing obtains virtual value, and virtual value is switched to DC voltage
Signal；
Step 3, d. c. voltage signal is become into corresponding digital signal by analog-to-digital conversion；
Step 4, digital signal is carried out according to attenuation coefficient being converted to actual real available value.
Further, the calculation processing includes being averaged to after sampled value progress square, then calculates square root again.
A kind of true rms measurement circuit of random waveform, including
Instantaneous voltage signal is carried out decaying tune for receiving the instantaneous voltage signal of random waveform by front end conditioning circuit
It manages into virtual value to turn in the voltage range that direct current integrated circuit can be handled, the voltage signal after conditioning is filtered rear defeated
Turn direct current integrated circuit to virtual value out；
Virtual value turns direct current integrated circuit, and for being sampled to received voltage signal, calculation processing obtains virtual value,
Virtual value is switched to corresponding d. c. voltage signal to export to analog-digital converter；
Analog-digital converter is exported for d. c. voltage signal to be become corresponding digital signal by analog-to-digital conversion to miniature
Control unit；
Miniature control unit carries out digital signal to be converted to reality for the attenuation coefficient according to front end conditioning circuit
Real available value.
Further, the front end conditioning circuit includes resistance R1, resistance R2, resistance R3, resistance R4 and amplifier U1, institute
State resistance R1, resistance R2 series connection, input terminal of the resistance R1 other end as front end conditioning circuit, the resistance R2 other end
The positive input terminal of amplifier U1 is connected, the one end the resistance R3 is connected between resistance R1 and resistance R2, the other end is grounded, described
The one end resistance R4 ground connection, the other end connect the negative input end of amplifier U1, and the output end of the amplifier U1 is improved as front end
The output end of circuit.
Further, it includes slide rheostat R5, slide rheostat R6, resistance that the virtual value, which turns direct current integrated circuit,
R7, resistance R8, resistance R9, capacitor C1, capacitor C2 and virtual value turn direct current chip U2, and the one end the slide rheostat R5 connects just
Power supply, other end connection negative supply, sliding end connection virtual value turn the compensating end of direct current chip U2, the slide rheostat R6's
Characteristic input terminal, the other end and the sliding end that one end connection virtual value turns direct current chip U2 are respectively connected with valid value and turn direct current chip U2
Output end and the one end resistance R9, the resistance R9 other end connect the one end resistance R8, the resistance R8 other end connect capacitor C1 anode, electricity
Hold C1 cathode ground connection, the one end resistance R7 connection virtual value turns the buffer inputs of direct current chip U2, other end connection capacitor
C1 anode, the capacitor C2 anode connection virtual value turn the buffer output terminal of direct current chip U2, cathode connection one end resistance R8, have
The buffer output terminal that valid value turns direct current chip U2 turns the output end of direct current integrated circuit as virtual value.
The present invention will be taken according to the mathematical definition of virtual value by acquiring the instantaneous value of waveform voltage to be measured after its square
Then average value calculates its square root again, obtain its virtual value.This measurement method must be defined according to virtual value completely, to wave
The shape of shape does not require, and measurement method is simple and effective, versatile.And the integrated electricity of direct current is turned using dedicated virtual value
Road, can accurately measure the real available value of random waveform rather than traditional measurement method can only accurately measure the effective of sine wave like that
Value.
Detailed description of the invention
Fig. 1 is the functional block diagram of measuring circuit of the present invention.
Fig. 2 is the schematic diagram of front end conditioning circuit of the present invention.
Fig. 3 is the schematic diagram that virtual value of the present invention turns direct current integrated circuit.
Specific embodiment
The following further describes the present invention in detail with reference to the accompanying drawings and specific embodiments, convenient for this hair is well understood
It is bright, but they limiting the invention.
A kind of true rms measurement method of random waveform of the present invention, comprising the following steps:
Step 1, the instantaneous voltage signal for obtaining random waveform is decayed to instantaneous voltage signal, is filtered；
Step 2, to treated, signal is sampled, calculation processing obtains virtual value, and virtual value is switched to DC voltage
Signal；Calculation processing is specifically included to be averaged to after sampled value progress square, then calculates square root again.
Step 3, d. c. voltage signal is become into corresponding digital signal by analog-to-digital conversion；
Step 4, digital signal is carried out according to attenuation coefficient being converted to actual real available value.
For the true rms measurement method for realizing above-mentioned random waveform, the present invention provides a kind of real available value of random waveform
Measuring circuit, as shown in Figure 1, including
Instantaneous voltage signal is carried out decaying tune for receiving the instantaneous voltage signal of random waveform by front end conditioning circuit 1
It manages into virtual value to turn in the voltage range that direct current integrated circuit can be handled, the voltage signal after conditioning is filtered rear defeated
Turn direct current integrated circuit to virtual value out；
Virtual value turns direct current integrated circuit 2, and for being sampled to received voltage signal, calculation processing obtains effectively
Value, switchs to corresponding d. c. voltage signal for virtual value and exports to analog-digital converter；Calculation processing specifically include to sampled value into
It is averaged after row square, then calculates square root again.
Analog-digital converter 3, it is total by SPI for d. c. voltage signal to be become corresponding digital signal by analog-to-digital conversion
Line is exported to miniature control unit.
Miniature control unit 4 carries out digital signal to be converted to reality for the attenuation coefficient according to front end conditioning circuit
The real available value on border.
As shown in Fig. 2, front end conditioning circuit 1 includes resistance R1, resistance R2, resistance R3, resistance R4 and amplifier U1, it is described
Resistance R1, resistance R2 series connection, input terminal of the resistance R1 other end as front end conditioning circuit, the resistance R2 other end connect
The positive input terminal of amplifier U1 is connect, the one end the resistance R3 is connected between resistance R1 and resistance R2, the other end is grounded, the electricity
The negative input end of the one end R4 ground connection, other end connection amplifier U1 is hindered, the output end of the amplifier U1 improves electricity as front end
The output end on road.
As shown in figure 3, virtual value turn direct current integrated circuit 2 include slide rheostat R5, slide rheostat R6, resistance R7,
Resistance R8, resistance R9, capacitor C1, capacitor C2 and virtual value turn direct current chip U2, and the one end the slide rheostat R5 connects positive electricity
Source, the other end connect negative supply, sliding end connection virtual value turns the compensating end of direct current chip U2, and the one of the slide rheostat R6
Characteristic input terminal, the other end and the sliding end that end connection virtual value turns direct current chip U2 are respectively connected with valid value and turn direct current chip U2's
Output end and the one end resistance R9, the resistance R9 other end connect the one end resistance R8, and the resistance R8 other end connects capacitor C1 anode, capacitor
C1 cathode ground connection, the one end resistance R7 connection virtual value turn the buffer inputs of direct current chip U2, other end connection capacitor C1
Anode, the capacitor C2 anode connection virtual value turn the buffer output terminal of direct current chip U2, cathode connection one end resistance R8, effectively
The buffer output terminal that value turns direct current chip U2 turns the output end of direct current integrated circuit as virtual value.
The content being not described in detail in this specification belongs to the prior art well known to professional and technical personnel in the field.
Claims (5)
1. a kind of true rms measurement method of random waveform, it is characterised in that: the following steps are included:
Step 1, the instantaneous voltage signal for obtaining random waveform is decayed to instantaneous voltage signal, is filtered；
Step 2, to treated, signal is sampled, calculation processing obtains virtual value, and virtual value is switched to d. c. voltage signal；
Step 3, d. c. voltage signal is become into corresponding digital signal by analog-to-digital conversion；
Step 4, digital signal is carried out according to attenuation coefficient being converted to actual real available value.
2. the true rms measurement method of random waveform according to claim 1, it is characterised in that: the calculation processing packet
It includes and is averaged to after sampled value progress square, then calculate square root again.
3. a kind of true rms measurement circuit of random waveform, it is characterised in that: including
Front end conditioning circuit, for receiving the instantaneous voltage signal of random waveform, by instantaneous voltage signal carry out decaying conditioning at
Virtual value turns in the voltage range that direct current integrated circuit can be handled, exported after being filtered to the voltage signal after conditioning to
Virtual value turns direct current integrated circuit；
Virtual value turns direct current integrated circuit, and for being sampled to received voltage signal, calculation processing obtains virtual value, will have
Valid value switchs to corresponding d. c. voltage signal and exports to analog-digital converter；
Analog-digital converter is exported for d. c. voltage signal to be become corresponding digital signal by analog-to-digital conversion to miniature control
Unit；
Miniature control unit be converted to digital signal actual true for the attenuation coefficient according to front end conditioning circuit
Virtual value.
4. the true rms measurement method of random waveform according to claim 1, it is characterised in that: the front end conditioning electricity
Road includes resistance R1, resistance R2, resistance R3, resistance R4 and amplifier U1, the resistance R1, resistance R2 series connection, the resistance R1
Input terminal of the other end as front end conditioning circuit, the positive input terminal of the resistance R2 other end connection amplifier U1, the electricity
Resistance one end R3 is connected between resistance R1 and resistance R2, the other end is grounded, the one end resistance R4 ground connection, other end connection amplification
The negative input end of device U1, output end of the output end of the amplifier U1 as front end conditioning circuit.
5. the true rms measurement circuit of random waveform according to claim 1, it is characterised in that: the virtual value turns straight
Stream integrated circuit include slide rheostat R5, slide rheostat R6, resistance R7, resistance R8, resistance R9, capacitor C1, capacitor C2 and
Virtual value turns direct current chip U2, and the one end the slide rheostat R5 connects positive supply, other end connection negative supply, sliding end connection
Virtual value turns the compensating end of direct current chip U2, and one end connection virtual value of the slide rheostat R6 turns the characteristic of direct current chip U2
Input terminal, the other end and sliding end be respectively connected with valid value turn direct current chip U2 output end and the one end resistance R9, resistance R9 it is another
End connection one end resistance R8, the resistance R8 other end connect capacitor C1 anode, capacitor C1 cathode ground connection, the connection of the one end the resistance R7
Virtual value turns the buffer inputs of direct current chip U2, other end connection capacitor C1 anode, and the capacitor C2 anode connects virtual value
Turn buffer output terminal, cathode connection one end resistance R8 of direct current chip U2, the buffer output terminal that virtual value turns direct current chip U2 is made
Turn the output end of direct current integrated circuit for virtual value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201810847638.7A CN109239443A (en) | 2018-07-27 | 2018-07-27 | A kind of the true rms measurement method and circuit of random waveform |
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| CN201810847638.7A CN109239443A (en) | 2018-07-27 | 2018-07-27 | A kind of the true rms measurement method and circuit of random waveform |
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| CN201810847638.7A Pending CN109239443A (en) | 2018-07-27 | 2018-07-27 | A kind of the true rms measurement method and circuit of random waveform |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117783614A (en) * | 2024-02-26 | 2024-03-29 | 北京励芯泰思特测试技术有限公司 | Alternating current signal generation and measurement system and method |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3275752B2 (en) * | 1997-01-29 | 2002-04-22 | 日本電気株式会社 | Level meter device |
| CN101303374A (en) * | 2007-05-10 | 2008-11-12 | 上海电力表计技术服务公司 | Automatic voltage regulation controller and method |
| CN201637773U (en) * | 2010-04-13 | 2010-11-17 | 浙江容大电力设备制造有限公司 | Collecting circuit of true effective value of multi-path alternating current signals |
| CN102539892A (en) * | 2012-01-16 | 2012-07-04 | 南京磐能电力科技股份有限公司 | Method for obtaining true effective values of AC (alternating current) signals |
| CN202339369U (en) * | 2011-12-01 | 2012-07-18 | 北京航天测控技术有限公司 | Alternating current low-frequency RMS (Root Mean Square) value conversion device |
| CN104267046A (en) * | 2014-07-31 | 2015-01-07 | 浙江大学 | Device and method for microwave transmission method-based detection of water content of oily sludge deposited at tank bottom in storage and transport |
| CN204177861U (en) * | 2014-11-10 | 2015-02-25 | 重庆电子工程职业学院 | A kind of precisely numerical monitor ac millivoltmeter |
-
2018
- 2018-07-27 CN CN201810847638.7A patent/CN109239443A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3275752B2 (en) * | 1997-01-29 | 2002-04-22 | 日本電気株式会社 | Level meter device |
| CN101303374A (en) * | 2007-05-10 | 2008-11-12 | 上海电力表计技术服务公司 | Automatic voltage regulation controller and method |
| CN201637773U (en) * | 2010-04-13 | 2010-11-17 | 浙江容大电力设备制造有限公司 | Collecting circuit of true effective value of multi-path alternating current signals |
| CN202339369U (en) * | 2011-12-01 | 2012-07-18 | 北京航天测控技术有限公司 | Alternating current low-frequency RMS (Root Mean Square) value conversion device |
| CN102539892A (en) * | 2012-01-16 | 2012-07-04 | 南京磐能电力科技股份有限公司 | Method for obtaining true effective values of AC (alternating current) signals |
| CN104267046A (en) * | 2014-07-31 | 2015-01-07 | 浙江大学 | Device and method for microwave transmission method-based detection of water content of oily sludge deposited at tank bottom in storage and transport |
| CN204177861U (en) * | 2014-11-10 | 2015-02-25 | 重庆电子工程职业学院 | A kind of precisely numerical monitor ac millivoltmeter |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117783614A (en) * | 2024-02-26 | 2024-03-29 | 北京励芯泰思特测试技术有限公司 | Alternating current signal generation and measurement system and method |
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Application publication date: 20190118 |