CN207528811U - AC voltage sampling circuit with isolation - Google Patents
AC voltage sampling circuit with isolation Download PDFInfo
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- CN207528811U CN207528811U CN201720897204.9U CN201720897204U CN207528811U CN 207528811 U CN207528811 U CN 207528811U CN 201720897204 U CN201720897204 U CN 201720897204U CN 207528811 U CN207528811 U CN 207528811U
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Abstract
The utility model is related to micro-capacitance sensor fields; the open AC voltage sampling circuit with isolation, the AC voltage sampling circuit of band isolation include sequentially connected resistor voltage divider circuit, add circuit, linear optical coupling isolation circuit, follow circuit, limiter protection circuit and AD Acquisition Circuit；The linear optical coupling isolation circuit carries out light-coupled isolation between forceful electric power and light current.The defects of AC voltage sampling circuit of band isolation overcomes AC voltage sampling of the prior art, realizes electrical isolation, it is also ensured that the precision of voltage measurement.
Description
Technical field
The utility model is related to micro-capacitance sensor fields, and in particular, to the AC voltage sampling circuit with isolation.
Background technology
It in micro-grid system, needs to monitor various parameters of electric power, to ensure the quality of power supply.Existing alternating voltage is adopted
Collecting system is generally made of voltage transformer or Hall sensor plus MCU, but the voltage transformer that when voltage is larger is required
Or Hall sensor volume is all bigger, price is high.Voltage transformer primary side is multicircuit winding, there are bigger inductance,
Response speed is relatively low；And Hall sensor can not electrical isolation, extraneous electromagnetic interference can have an impact terminal.
So alternating voltage is acquired using voltage transformer or Hall sensor all defective.
Utility model content
The purpose of this utility model is to provide a kind of AC voltage sampling circuit of band isolation, the alternating voltage of band isolation
Acquisition Circuit overcomes the defects of AC voltage sampling of the prior art, realizes electrical isolation, it is also ensured that voltage is surveyed
The precision of amount.
To achieve these goals, the utility model provides a kind of AC voltage sampling circuit of band isolation, band isolation
AC voltage sampling circuit include sequentially connected resistor voltage divider circuit, add circuit, linear optical coupling isolation circuit, follow electricity
Road, limiter protection circuit and AD Acquisition Circuit；The linear optical coupling isolation circuit carries out light-coupled isolation between forceful electric power and light current.
Preferably, the resistor voltage divider circuit includes：Multiple divider resistances, multiple divider resistances are connected or simultaneously
Connection connection, to obtain the first required output voltage.
Preferably, the add circuit includes：The amplification chip and peripheral circuit of model LM224, the periphery electricity
Road is connected to the amplification chip, and the negative voltage of first output voltage is switched to positive voltage and obtains the second output electricity by cooperation
Pressure.
Preferably, the linear optical coupling isolation circuit includes：The opto-coupler chip of model HCNR201 and filter noise cancellation circuit,
The input terminal of the opto-coupler chip receives second output voltage, is filtered out in the opto-coupler chip by the filter noise cancellation circuit
Burr signal.
Preferably, the limiter protection circuit includes：The diode of two model 1N4148, two diodes connect
Be connected to it is described follow circuit so that the upper limit of the output voltage for following circuit is to+3.3V, lower limit to 0V.
Preferably, the filter noise cancellation circuit includes：First capacitance and the second capacitance, one end of first capacitance are connected to institute
State the input terminal of opto-coupler chip；Second capacitance connection is in the output terminal of the opto-coupler chip.
Preferably, first capacitance and the capacitance that the second capacitance is 20pF.
Through the above technical solutions, input voltage (being set as 220V) is sampled to it there are certain surplus, at present
Tentative voltage is 250V, if sampled voltage has adjustment, can suitably adjust the resistance value of divider resistance.General thought：Because AD is inputted
Range of signal is 0~3.3V, and the voltage of 220V is sent by transformation in AD, and electric resistance partial pressure output first is about -1V~+1V
Between, then make output voltage between 0~3V by add circuit.Using light-coupled isolation between forceful electric power and light current, make input
Output has good linear relationship while isolation, the amplitude limiter circuit of 3.3V is finally added before AD acquisitions, with protection
DSP。
Other features and advantages of the utility model will be described in detail in subsequent specific embodiment part.
Description of the drawings
Attached drawing is to be used to provide a further understanding of the present invention, and a part for constitution instruction, and following
Specific embodiment together for explaining the utility model, but do not form the limitation to the utility model.In the accompanying drawings：
Fig. 1 is a kind of circuit block diagram of the AC voltage sampling circuit for band isolation for illustrating the utility model；
Fig. 2 is a kind of circuit connection diagram of the AC voltage sampling circuit for band isolation for illustrating the utility model；
Fig. 3 is a kind of resistor voltage divider circuit connection of the AC voltage sampling circuit for band isolation for illustrating the utility model
Figure；
Fig. 4 is a kind of add circuit connection figure of the AC voltage sampling circuit for band isolation for illustrating the utility model；
Fig. 5 is that a kind of linear optical coupling isolation circuit of the AC voltage sampling circuit for band isolation for illustrating the utility model connects
Map interlinking；
Fig. 6 is that a kind of circuit for following circuit of the AC voltage sampling circuit for band isolation for illustrating the utility model connects
Figure；
Fig. 7 is a kind of circuit of the limiter protection circuit of the AC voltage sampling circuit for band isolation for illustrating the utility model
Connection figure.
Specific embodiment
Specific embodiment of the present utility model is described in detail below in conjunction with attached drawing.It should be understood that herein
Described specific embodiment is only used for describing and explaining the present invention, and is not intended to limit the utility model.
The utility model provides a kind of AC voltage sampling circuit of band isolation, the AC voltage sampling circuit of band isolation
Including sequentially connected resistor voltage divider circuit, add circuit, linear optical coupling isolation circuit, follow circuit, limiter protection circuit and
AD Acquisition Circuit；The linear optical coupling isolation circuit carries out light-coupled isolation between forceful electric power and light current.
Through the above technical solutions, input voltage (being set as 220V) is sampled to it there are certain surplus, at present
Tentative voltage is 250V, if sampled voltage has adjustment, can suitably adjust the resistance value of divider resistance.General thought：Because AD is inputted
Range of signal is 0~3.3V, and the voltage of 220V is sent by transformation in AD, and electric resistance partial pressure output first is about -1V~+1V
Between, then make output voltage between 0~3V by add circuit.Using light-coupled isolation between forceful electric power and light current, make input
Output has good linear relationship while isolation, the amplitude limiter circuit of 3.3V is finally added before AD acquisitions, with protection
DSP。
In a kind of specific embodiment of the utility model, the resistor voltage divider circuit can include：Multiple partial pressure electricity
Resistance, multiple divider resistances are connected in series or parallel, to obtain the first required output voltage.
As shown in Figure 3；Resistor voltage divider circuit is relatively simple, mainly the selection of resistance type and resistance value, Vr_A to be made
Value be about 1V, and Vr_A=R1/ (R1+R2), the utility model select the essence of the Low Drift Temperature of R1=4K, R2=2000K
Cipher telegram hinders, and because R2 resistance values are excessive, selects R1=R2=R5=R6=300K, R3=R4=R7=R8=200K, R9=4K,
Then output voltage Vr_A is between -0.6V~+0.6V
In this kind of embodiment, the add circuit can include：The amplification chip of model LM224 and periphery electricity
Road, the peripheral circuit is connected to the amplification chip, and coordinates the negative voltage of first output voltage switching to positive voltage
Obtain the second output voltage.
Because alternating voltage has a negative electricity laminate section, and the AD acquisition voltage ranges of DSP 0 between 3.3V, so needing
Add an add circuit that the part of negative voltage is made to switch to positive voltage, the add circuit of the utility model selection+1.5V, by R10,
R11, R12, R13 resistance and LM224 compositions, circuit diagram are as shown in Figure 4：
Vf_A=[R11/ (R10+R11) * V1+R10/ (R10+R11) * Vr_A] * (1+R13/R12)；
Select R10=R11=R12=R13=10K, V1=1.5V, then Vf_A=Vr_A+1.5V, final range+
0.9V~+2.1V.
In this kind of embodiment, the linear optical coupling isolation circuit can include：The opto-coupler chip of model HCNR201
And filter noise cancellation circuit, the input terminal of the opto-coupler chip receive second output voltage, and institute is filtered out by the filter noise cancellation circuit
State the burr signal in opto-coupler chip.
The linear optical coupling that the utility model uses is HCNR201, wherein input of 1,2 pins as isolation signals, 3,4 draw
For feeding back, 5,6 pins are used to export foot.1st, the electric current between 2 pins is denoted as IF, between 3,4 pins between 5,6 pins
Electric current is denoted as IPD1 and IPD2, wherein IF=Vf_A/R16, IPD1=Vf_A/R14, IPD2=Vout/R15, K=respectively
IPD1/IPD2, inquiry HCNR201 databook understand K=1 ± 5% (being determined therewith after the completion of chip manufacturing), so Vf_
A/Vout=KR14/R15, input and output are linear, and directly proportional to the value of R74/R75.Its range of linearity work electricity
Stream is in 1~20mA, by add circuit output voltage between 0~+3V, it is contemplated that the IF the big more is conducive to energy transmission, institute
Using the value of R16 as 3V/20mA=150 Europe.Due between range of linearity 5uA~50uA of opto-coupled feedback electric current IPD1, then R14
Value for 3V/50uA=60K, R15=R14=60K, achieve the purpose that only isolate and not amplify, Vout is approximately equal to Vf_ at this time
A, and it is linear with Vf_A, range is between+0.9V~+2.1V.Burr letter in the main filtering circuits of capacitance C1 and C2
Number, the noise of circuit is reduced, is recommended according to HCNR201 databooks, selects 20pF.Circuit is as shown in Figure 5.
In a kind of specific embodiment of the utility model, the limiter protection circuit can include：Two models
The diode of 1N4148, two diodes be connected to it is described follow circuit so that the output voltage for following circuit
The upper limit to+3.3V, lower limit to 0V.
Circuit is followed to be connected directly with output terminal by the reverse input end of LM224 to form, input impedance can be improved, is reduced
Output impedance improves antijamming capability.The sampled voltage of AD1 is equal to Vout at this time, and range is between+0.9V~+2.1V.Circuit
As shown in Figure 6.
In this kind of embodiment, the filter noise cancellation circuit can include：First capacitance and the second capacitance, first capacitance
One end be connected to the input terminal of the opto-coupler chip；Second capacitance connection is in the output terminal of the opto-coupler chip.
Amplitude limiter circuit is by D1, two 1N4148 diodes compositions of D2, the difference upper limit to+3.3V, lower limit to 0V, after protection
The DSP of grade.The sampled voltage range of AD1 will not trigger limiter protection circuit between+0.9V~+2.1V under normal circumstances.Electricity
Road is as shown in Figure 7.
Certainly, in this kind of embodiment, first capacitance and the capacitance that the second capacitance is 20pF.
The preferred embodiment of the utility model, still, the utility model and unlimited are described in detail above in association with attached drawing
Detail in the above embodiment, can be to the skill of the utility model in the range of the technology design of the utility model
Art scheme carries out a variety of simple variants, these simple variants belong to the scope of protection of the utility model.
It is further to note that specific technical features described in the above specific embodiments, in not lance
It in the case of shield, can be combined by any suitable means, in order to avoid unnecessary repetition, the utility model is to each
The possible combination of kind no longer separately illustrates.
In addition, arbitrary combination can also be carried out between a variety of different embodiments of the utility model, as long as it is not disobeyed
The thought of the utility model is carried on the back, should equally be considered as content disclosed in the utility model.
Claims (7)
1. a kind of AC voltage sampling circuit of band isolation, which is characterized in that the AC voltage sampling circuit of band isolation includes
Sequentially connected resistor voltage divider circuit, linear optical coupling isolation circuit, follows circuit, limiter protection circuit and AD to adopt at add circuit
Collector；The linear optical coupling isolation circuit carries out light-coupled isolation between forceful electric power and light current.
2. the AC voltage sampling circuit of band isolation according to claim 1, which is characterized in that the resistor voltage divider circuit
Including：Multiple divider resistances, multiple divider resistances are connected in series or parallel, to obtain the first required output electricity
Pressure.
3. the AC voltage sampling circuit of band isolation according to claim 2, which is characterized in that the add circuit packet
It includes：The amplification chip and peripheral circuit of model LM224, the peripheral circuit are connected to the amplification chip, and coordinate by
The negative voltage of first output voltage switchs to positive voltage and obtains the second output voltage.
4. the AC voltage sampling circuit of band isolation according to claim 3, which is characterized in that the linear optical coupling isolation
Circuit includes：The opto-coupler chip of model HCNR201 and filter noise cancellation circuit, the input terminal of the opto-coupler chip receive described second
Output voltage filters out the burr signal in the opto-coupler chip by the filter noise cancellation circuit.
5. the AC voltage sampling circuit of band isolation according to claim 1, which is characterized in that the limiter protection circuit
Including：The diode of two model 1N4148, two diodes be connected to it is described follow circuit so that described follow
The upper limit of the output voltage of circuit extremely+3.3V, lower limit to 0V.
6. the AC voltage sampling circuit of band isolation according to claim 4, which is characterized in that the filter noise cancellation circuit packet
It includes：First capacitance and the second capacitance, one end of first capacitance are connected to the input terminal of the opto-coupler chip；Second electricity
Hold the output terminal for being connected to the opto-coupler chip.
7. the AC voltage sampling circuit of band according to claim 6 isolation, which is characterized in that first capacitance and the
Two capacitances are the capacitance of 20pF.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720897204.9U CN207528811U (en) | 2017-07-24 | 2017-07-24 | AC voltage sampling circuit with isolation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720897204.9U CN207528811U (en) | 2017-07-24 | 2017-07-24 | AC voltage sampling circuit with isolation |
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| Publication Number | Publication Date |
|---|---|
| CN207528811U true CN207528811U (en) | 2018-06-22 |
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ID=62575475
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| Application Number | Title | Priority Date | Filing Date |
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| CN201720897204.9U Active CN207528811U (en) | 2017-07-24 | 2017-07-24 | AC voltage sampling circuit with isolation |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107179435A (en) * | 2017-07-24 | 2017-09-19 | 安徽华腾电气有限公司 | AC voltage sampling circuit with isolation |
| CN113447707A (en) * | 2021-07-08 | 2021-09-28 | 深圳市誉娇诚科技有限公司 | High-voltage direct-current bus voltage detection circuit for electric automobile |
-
2017
- 2017-07-24 CN CN201720897204.9U patent/CN207528811U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107179435A (en) * | 2017-07-24 | 2017-09-19 | 安徽华腾电气有限公司 | AC voltage sampling circuit with isolation |
| CN113447707A (en) * | 2021-07-08 | 2021-09-28 | 深圳市誉娇诚科技有限公司 | High-voltage direct-current bus voltage detection circuit for electric automobile |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20181010 Address after: 241000 Anhui two Wuhu Yijiang high tech Industrial Park, No. 01, two workshop, No. Patentee after: Wuhu Kang ai Er Electric Co., Ltd. Address before: 241000 the 5 floor of the administrative committee of Wuhu high tech Development Zone, Anhui Patentee before: Anhui Huateng Electric Co. Ltd. |
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| TR01 | Transfer of patent right |