CN216816781U - Anti-interference alternating voltage sampling circuit - Google Patents
Anti-interference alternating voltage sampling circuit Download PDFInfo
- Publication number
- CN216816781U CN216816781U CN202220155517.8U CN202220155517U CN216816781U CN 216816781 U CN216816781 U CN 216816781U CN 202220155517 U CN202220155517 U CN 202220155517U CN 216816781 U CN216816781 U CN 216816781U
- Authority
- CN
- China
- Prior art keywords
- resistor
- capacitor
- module
- differential amplifier
- power supply
- 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
Images
Landscapes
- Measurement Of Current Or Voltage (AREA)
Abstract
The utility model discloses an anti-interference alternating voltage sampling circuit which comprises a resistance voltage division module, a power supply filtering module, a reference bias module, a differential conditioning module and a signal filtering module, wherein the resistance voltage division module is connected with the power supply filtering module; the differential conditioning module comprises a differential amplifier, the resistance voltage dividing module is connected with the input end of the differential amplifier, and alternating current voltage to be sampled is input into the resistance voltage dividing module; the power supply filtering module and the reference bias module are both connected with the power supply end of the differential amplifier; and the signal filtering module is connected with the output end of the differential amplifier. The application provides an anti-interference alternating voltage sampling circuit can restrain the influence of high frequency switching signal to voltage sampling signal, has advantages such as low cost, high accuracy, high reliability and high interference immunity.
Description
Technical Field
The utility model belongs to the technical field of power electronics, and particularly relates to an anti-interference alternating voltage sampling circuit.
Background
In the field of power electronics, more and more power devices require measurement of ac voltage. For example, when the inverter is connected to the grid, voltages at two ends need to be collected, and the grid connection can be performed only when the phases and the magnitudes of the voltages are consistent.
In power equipment, alternating voltage sampling is often divided into a direct type and an isolated type. The common isolated type has a voltage sensor, and has the characteristics of high precision and high price. The direct circuit has the advantages of wide application, non-isolation, low cost and limited anti-interference capability, and particularly, in a high-switching-frequency power converter, a high-frequency switching signal is often superposed in a voltage sampling circuit. How to suppress the influence of the high-frequency switching signal on the voltage sampling signal and enable the direct low-cost voltage sampling circuit to achieve high interference resistance, high precision and high reliability is a subject to be studied by those skilled in the art.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide an anti-interference alternating voltage sampling circuit to solve the technical problem.
In order to achieve the purpose, the utility model adopts the following technical scheme:
an anti-interference alternating voltage sampling circuit comprises a resistance voltage division module, a power supply filtering module, a reference bias module, a differential conditioning module and a signal filtering module;
the differential conditioning module comprises a differential amplifier, the resistance voltage dividing module is connected with the input end of the differential amplifier, and alternating current voltage to be sampled is input into the resistance voltage dividing module;
the power supply filtering module and the reference bias module are both connected with the power supply end of the differential amplifier;
the signal filtering module is connected with the output end of the differential amplifier.
Optionally, the resistance voltage division module includes a first set of series resistors connected to the inverting input terminal of the differential amplifier and a second set of series resistors connected to the non-inverting input terminal of the differential amplifier;
one end of the first group of series resistors is also used for connecting the alternating voltage to be sampled, one end of the second group of series resistors is also connected with a grounding terminal, and a first capacitor is connected between one end of the first group of series resistors and one end of the second group of series resistors.
Optionally, the first set of series resistors includes a first resistor, a second resistor, a third resistor, and a fourth resistor, and the second set of series resistors includes a fifth resistor, a sixth resistor, a seventh resistor, and an eighth resistor;
the first resistor, the second resistor, the third resistor, the fifth resistor, the sixth resistor and the seventh resistor are all equal to 1M omega, and the fourth resistor and the eighth resistor are all equal to 1k omega;
the first capacitance is equal to 100 pF.
Optionally, the differential conditioning module further comprises a ninth resistor, a tenth resistor, a second capacitor, and a third capacitor;
after the ninth resistor and the second capacitor are connected in parallel, one end of the ninth resistor is connected with the non-inverting input end of the differential amplifier, and the other end of the ninth resistor is connected with the voltage output end of the reference bias module;
after the tenth resistor and the third capacitor are connected in parallel, one end of the tenth resistor is connected with the inverting input end of the differential amplifier, and the other end of the tenth resistor is connected with the output end of the differential amplifier.
Optionally, the ninth resistor and the tenth resistor are both equal to 11k Ω, and the second capacitor and the third capacitor are both equal to 33 pF.
Optionally, the power supply filtering module includes a magnetic bead, one end of the magnetic bead is connected to the first power supply, and the other end of the magnetic bead is connected to the power supply end of the differential amplifier;
and a fourth capacitor and a fifth capacitor which are connected in parallel are also connected between the other end of the magnetic bead and the grounding end.
Optionally, the reference bias module includes a second power supply, and the second power supply is a reference power supply capable of stably outputting a preset voltage;
the reference bias module further comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor and a sixth capacitor;
a first end of the eleventh resistor is connected with a power supply end of the differential amplifier, and a second end of the eleventh resistor is connected with a first end of the second power supply;
a first end of the twelfth resistor is connected to a second end of the eleventh resistor and a first end of the sixth capacitor, and the first end of the sixth capacitor is a voltage output end of the reference bias module;
a second end of the twelfth resistor is connected with a first end of the thirteenth resistor and a second end of the second power supply, and the second end of the second power supply can output the preset voltage;
and the third end of the second power supply, the second end of the thirteenth resistor and the second end of the sixth capacitor are all connected with a ground terminal.
Optionally, the signal filtering module includes a fourteenth resistor and a seventh capacitor;
a first end of the fourteenth resistor is connected to the output end of the differential amplifier, a second end of the fourteenth resistor is connected to a first end of the seventh capacitor, and a second end of the seventh capacitor is connected to a ground end.
Compared with the prior art, the embodiment of the utility model has the following beneficial effects:
the anti-interference alternating voltage sampling circuit provided by the embodiment of the utility model can measure alternating voltage and has the advantages of low cost, high precision, high reliability, high anti-interference performance and the like.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
The structures, ratios, sizes, and the like shown in the present specification are only used for matching with the contents disclosed in the specification, so that those skilled in the art can understand and read the present invention, and do not limit the conditions for implementing the present invention, so that the present invention has no technical significance, and any structural modifications, changes in the ratio relationship, or adjustments of the sizes, without affecting the functions and purposes of the present invention, should still fall within the scope covered by the contents disclosed in the present invention.
Fig. 1 is a circuit diagram of an anti-interference ac voltage sampling circuit according to an embodiment of the present invention.
Illustration of the drawings:
AC _ in, alternating voltage; vo _ out, a sampling signal; u1, differential amplifier; u2, a second power supply; GND and a ground terminal; l1, magnetic beads;
r1, a first resistor; r2, a second resistor; r3, third resistor; r4, fourth resistor; r5, fifth resistor; r6, sixth resistor; r7, seventh resistor; r8, eighth resistor; r9, ninth resistor; r10, tenth resistor; r11, eleventh resistor; r12, twelfth resistor; r13, thirteenth resistor; r14, fourteenth resistance;
c1, a first capacitance; c2, a second capacitor; c3, a third capacitance; c4, a fourth capacitance; c5, a fifth capacitance; c6, a sixth capacitor; c7, a seventh capacitance.
Detailed Description
In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, the present embodiment provides an anti-interference ac voltage sampling circuit, which includes a resistor voltage dividing module, a power filter module, a reference bias module, a differential conditioning module, and a signal filter module.
The differential conditioning module comprises a differential amplifier U1, the resistance voltage dividing module is connected with the input end of the differential amplifier U1, and the alternating current voltage AC _ in to be sampled is input into the resistance voltage dividing module. The power supply filtering module and the reference bias module are both connected with the power supply end of the differential amplifier U1. The signal filtering module is connected with the output end of the differential amplifier U1. Specifically, the differential amplifier U1 is model OPA 450.
Specifically, the resistance voltage divider module can scale down the alternating voltage AC _ in or the like to an input voltage adapted to the differential amplifier U1. The resistive divider block includes a first set of series resistors connected to the inverting input of the differential amplifier U1 and a second set of series resistors connected to the non-inverting input of the differential amplifier U1. One end of the first group of series resistors is also used for connecting the alternating voltage AC _ in to be sampled, one end of the second group of series resistors is also connected with a ground terminal GND, and a first capacitor C1 is connected between one end of the first group of series resistors and one end of the second group of series resistors.
Specifically, the first series resistor group comprises a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4, and the second series resistor group comprises a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8. The first resistor R1, the second resistor R2, the third resistor R3, the fifth resistor R5, the sixth resistor R6 and the seventh resistor R7 are all equal to 1M Ω, and the fourth resistor R4 and the eighth resistor R8 are all equal to 1k Ω. The first capacitance C1 is equal to 100 pF.
Further, the differential conditioning module further includes a ninth resistor R9, a tenth resistor R10, a second capacitor C2, and a third capacitor C3. After the ninth resistor R9 and the second capacitor C2 are connected in parallel, one end of the ninth resistor R9 is connected with the non-inverting input end of the differential amplifier U1, and the other end of the ninth resistor R8932 is connected with the voltage output end of the reference bias module. After the tenth resistor R10 and the third capacitor C3 are connected in parallel, one end of the tenth resistor R10 is connected to the inverting input terminal of the differential amplifier U1, and the other end of the tenth resistor R10 is connected to the output terminal of the differential amplifier U1. The ninth resistor R9 and the tenth resistor R10 are both equal to 11k Ω, and the second capacitor C2 and the third capacitor C3 are both equal to 33 pF.
The first capacitor C1 is used for filtering out high frequency noise interference. According to the above values, the amplification factor of the differential amplifier U1 is equal to the tenth resistor R10 divided by the fourth resistor R4, i.e., 11 times. The second capacitor C2 and the third capacitor C3 are used to filter out high frequency interference.
Further, the reference bias module includes a second power supply U2, and the second power supply U2 is a reference power supply capable of stably outputting a preset voltage. The reference bias module further includes an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, and a sixth capacitor C6.
The eleventh resistor R11 has a first terminal connected to the power supply terminal of the differential amplifier U1 and a second terminal connected to a first terminal of the second power supply U2. A first end of the twelfth resistor R12 is connected to the second end of the eleventh resistor R11 and the first end of the sixth capacitor C6, and the first end of the sixth capacitor C6 is a voltage output end of the reference bias module. The second end of the twelfth resistor R12 is connected to the first end of the thirteenth resistor R13 and the second end of the second power source U2, and the second end of the second power source U2 can output a preset voltage. The third terminal of the second power source U2, the second terminal of the thirteenth resistor R13, and the second terminal of the sixth capacitor C6 are all connected to the ground GND. Specifically, the second power supply U2 has a model AZ 431.
Specifically, the preset voltage is 1.25V. The voltage at the voltage output terminal of the reference bias module is 1.65V. This voltage is applied to the non-inverting input of the differential amplifier U1, biasing the differential amplifier U1 so that it can capture the entire AC voltage AC _ in waveform. The eleventh resistor R11 and the sixth capacitor C6 play a role in limiting and stabilizing current.
Further, the power supply filtering module comprises a magnetic bead L1, one end of the magnetic bead L1 is connected with the first power supply, and the other end of the magnetic bead L1 is connected with the power supply end of the differential amplifier U1. Wherein the output of the first power supply is 3.3V. A fourth capacitor C4 and a fifth capacitor C5 which are connected in parallel are further connected between the other end of the magnetic bead L1 and the ground end GND, and the fourth capacitor C4 and the fifth capacitor C5 play roles in filtering and voltage stabilizing and can filter switching noise. In the circuit, the magnetic bead L1 has the capacity of suppressing high-frequency noise and spike interference of a signal wire and absorbing electrostatic pulses, so that the anti-interference capacity of the circuit is enhanced.
Further, the signal filtering module comprises a fourteenth resistor R14 and a seventh capacitor C7; a first end of the fourteenth resistor R14 is connected to the output terminal of the differential amplifier U1, a second end thereof is connected to a first end of the seventh capacitor C7, and a second end of the seventh capacitor C7 is connected to the ground GND. The fourteenth resistor R14 and the seventh capacitor C7 can filter the output signal to filter out high frequency noise interference, so that the output sampling signal Vo _ out is more accurate.
In summary, the anti-interference ac voltage sampling circuit provided by this embodiment can suppress the influence of the high-frequency switching signal on the voltage sampling signal, and implement ac voltage sampling with low cost, high accuracy, high reliability and high anti-interference.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (8)
1. An anti-interference alternating voltage sampling circuit is characterized by comprising a resistance voltage division module, a power supply filtering module, a reference bias module, a differential conditioning module and a signal filtering module;
the differential conditioning module comprises a differential amplifier, the resistance voltage dividing module is connected with the input end of the differential amplifier, and alternating current voltage to be sampled is input into the resistance voltage dividing module;
the power supply filtering module and the reference bias module are both connected with the power supply end of the differential amplifier;
the signal filtering module is connected with the output end of the differential amplifier.
2. The antijam AC voltage sampling circuit of claim 1, wherein the resistor divider module includes a first set of series resistors connected to the inverting input of the differential amplifier and a second set of series resistors connected to the non-inverting input of the differential amplifier;
one end of the first group of series resistors is also used for connecting the alternating voltage to be sampled, one end of the second group of series resistors is also connected with a grounding terminal, and a first capacitor is connected between one end of the first group of series resistors and one end of the second group of series resistors.
3. The tamper-resistant ac voltage sampling circuit of claim 2, wherein the first set of series resistances comprises a first resistance, a second resistance, a third resistance, and a fourth resistance, and wherein the second set of series resistances comprises a fifth resistance, a sixth resistance, a seventh resistance, and an eighth resistance;
the first resistor, the second resistor, the third resistor, the fifth resistor, the sixth resistor and the seventh resistor are all equal to 1M omega, and the fourth resistor and the eighth resistor are all equal to 1k omega;
the first capacitance is equal to 100 pF.
4. The antijam AC voltage sampling circuit of claim 1, wherein the differential conditioning module further includes a ninth resistor, a tenth resistor, a second capacitor, and a third capacitor;
after the ninth resistor and the second capacitor are connected in parallel, one end of the ninth resistor is connected with the non-inverting input end of the differential amplifier, and the other end of the ninth resistor is connected with the voltage output end of the reference bias module;
after the tenth resistor and the third capacitor are connected in parallel, one end of the tenth resistor is connected with the inverting input end of the differential amplifier, and the other end of the tenth resistor is connected with the output end of the differential amplifier.
5. The tamper-resistant AC voltage sampling circuit of claim 4, wherein the ninth resistor and the tenth resistor are each equal to 11kΩ, and wherein the second capacitor and the third capacitor are each equal to 33 pF.
6. The anti-jamming AC voltage sampling circuit according to claim 1, wherein the power filter module includes a magnetic bead, one end of the magnetic bead is connected to a first power source, and the other end of the magnetic bead is connected to a power source terminal of the differential amplifier;
and a fourth capacitor and a fifth capacitor which are connected in parallel are also connected between the other end of the magnetic bead and the grounding end.
7. The antijam AC voltage sampling circuit of claim 1, wherein the reference bias module includes a second power supply, the second power supply being a reference power supply capable of stably outputting a predetermined voltage;
the reference bias module further comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor and a sixth capacitor;
a first end of the eleventh resistor is connected with a power supply end of the differential amplifier, and a second end of the eleventh resistor is connected with a first end of the second power supply;
a first end of the twelfth resistor is connected to a second end of the eleventh resistor and a first end of the sixth capacitor, and the first end of the sixth capacitor is a voltage output end of the reference bias module;
a second end of the twelfth resistor is connected with a first end of the thirteenth resistor and a second end of the second power supply, and the second end of the second power supply can output the preset voltage;
and the third end of the second power supply, the second end of the thirteenth resistor and the second end of the sixth capacitor are all connected with a ground terminal.
8. The antijam AC voltage sampling circuit of claim 1, wherein the signal filtering module includes a fourteenth resistor and a seventh capacitor;
a first end of the fourteenth resistor is connected to the output end of the differential amplifier, a second end of the fourteenth resistor is connected to a first end of the seventh capacitor, and a second end of the seventh capacitor is connected to a ground end.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220155517.8U CN216816781U (en) | 2022-01-20 | 2022-01-20 | Anti-interference alternating voltage sampling circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220155517.8U CN216816781U (en) | 2022-01-20 | 2022-01-20 | Anti-interference alternating voltage sampling circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216816781U true CN216816781U (en) | 2022-06-24 |
Family
ID=82066055
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202220155517.8U Active CN216816781U (en) | 2022-01-20 | 2022-01-20 | Anti-interference alternating voltage sampling circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216816781U (en) |
-
2022
- 2022-01-20 CN CN202220155517.8U patent/CN216816781U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN205562653U (en) | Current inducer | |
| CN103954821A (en) | Ripple voltage detection method of filer capacitor equivalent series resistor | |
| CN210015156U (en) | Current detection circuit, device and electric product | |
| CN107219402A (en) | A kind of circuit for quick measurement of DC resistance for power module port | |
| CN204964613U (en) | Zero -cross detection circuit | |
| CN206618791U (en) | A kind of wide-band capacitor compensating formula resitstance voltage divider | |
| CN216816781U (en) | Anti-interference alternating voltage sampling circuit | |
| CN109212448B (en) | Self-stabilizing zero circuit | |
| CN102496909B (en) | Simple leakage protector with multi-gear adjustable protection values and action time | |
| CN205643468U (en) | Electronic voltage transformer suitable for quality testing of smart power grids electric energy | |
| CN109342827B (en) | Circuit and method for measuring capacitance value through capacitance alternating current charge and discharge | |
| CN203054092U (en) | Apparatus for extracting DC (direct current) signal from AC-DC (alternating current-direct current) superposed signal | |
| CN111426874A (en) | Strong anti-interference wide-range alternating current permanent magnet synchronous motor current sampling circuit | |
| CN201285409Y (en) | Phase voltage detection circuit | |
| CN207234388U (en) | A kind of novel bus current foldback circuit | |
| CN202748160U (en) | Anti-interference temperature sampling circuit | |
| CN103412194B (en) | Capacitance measuring and calculating circuit | |
| CN114113781A (en) | Frequency measuring circuit of power system | |
| CN211930600U (en) | Intelligent low-voltage fault sensor simulation front-end conditioning circuit | |
| CN203054063U (en) | Input voltage measuring circuit for high-voltage frequency converter | |
| CN108562776B (en) | Power frequency rogowski coil with multi-range output | |
| CN214585714U (en) | Capacitance measuring device | |
| CN213023299U (en) | AC sampling circuit for power distribution gateway | |
| CN219891323U (en) | Wide-range sine wave zero-crossing phase sampling circuit | |
| CN202362376U (en) | Voltage loop signal processing circuit of three-phase electronic type electric energy meter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |