CN218549741U - Circuit for improving anti-electromagnetic interference capability of water quality analyzer - Google Patents
Circuit for improving anti-electromagnetic interference capability of water quality analyzer Download PDFInfo
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- CN218549741U CN218549741U CN202221474002.0U CN202221474002U CN218549741U CN 218549741 U CN218549741 U CN 218549741U CN 202221474002 U CN202221474002 U CN 202221474002U CN 218549741 U CN218549741 U CN 218549741U
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Abstract
The utility model discloses a circuit for improving the anti-electromagnetic interference capability of a water quality analyzer, which comprises a power supply, a lightning protection circuit, a filter protection circuit and a converter; the power supply is connected with the lightning protection circuit, the lightning protection circuit is connected with the filter circuit, the filter protection circuit is connected with the converter, and at least 2 common-mode choke coils are arranged in the filter protection circuit; the lightning protection circuit comprises a safety element, a first piezoresistor, a second piezoresistor, a third piezoresistor, a first current-limiting resistor, a second current-limiting resistor, a discharge gas tube and a thermistor; the safety piece is arranged on the alternating current zero line and at the access end of the lightning protection circuit; the first piezoresistor is arranged at a position between the alternating current zero line and the alternating current live line behind the safety element; the thermistor is arranged on an alternating current zero line behind the first piezoresistor; the second piezoresistor and the third piezoresistor are arranged in series at a position between the alternating current zero line and the alternating current live line behind the thermistor.
Description
Technical Field
The utility model belongs to the technical field of the anti-interference technique of device and specifically relates to an improve water quality analyzer anti-electromagnetic interference ability's circuit.
Background
The water quality analyzer is easily subjected to electromagnetic interference in the using process, and phenomena such as screen splash, device burnout and the like occur; the method for solving the problem in the prior art is mainly to ground a shell of the water quality analyzer or add a magnetic ring on a wire supply terminal strip of a display screen; or a first-stage anti-interference filter is added at the power supply end.
These methods, however, do not solve the problems of screen blooming and device burn-out; the problem that the water quality analyzer is easily interfered by electromagnetic interference, and a screen is scratched to burn out a device in the using process can not be efficiently solved through a level 1 anti-group pulse test of an EMC test.
SUMMERY OF THE UTILITY MODEL
The utility model discloses aim at: aiming at the problems, the circuit for improving the anti-electromagnetic interference capability of the water quality analyzer is provided, and the problems that the water quality analyzer is easily subjected to electromagnetic interference, a screen is patterned and devices are burnt out in the using process in the prior art are solved.
The utility model discloses a realize through following scheme:
a circuit for improving the anti-electromagnetic interference capability of a water quality analyzer comprises a power supply, a lightning protection circuit, a filter protection circuit and a converter; the power supply is connected with the lightning protection circuit, the lightning protection circuit is connected with the filter circuit, the filter protection circuit is connected with the converter, and at least 2 common-mode choke coils are arranged in the filter protection circuit.
Based on the structure of the circuit for improving the anti-electromagnetic interference capability of the water quality analyzer, the lightning protection circuit comprises a safety piece, a first piezoresistor, a second piezoresistor, a third piezoresistor, a first current-limiting resistor, a second current-limiting resistor, a discharge gas tube and a thermistor; the safety piece is arranged on the alternating current zero line and at the access end of the lightning protection circuit; the first piezoresistor is arranged at a position between the alternating current zero line and the alternating current live line behind the safety piece; the thermistor is arranged on an alternating current zero line behind the first piezoresistor; the second voltage dependent resistor and the third voltage dependent resistor are connected in series at a position between the alternating current zero line and the alternating current live line behind the thermistor.
Based on the structure of the circuit for improving the anti-electromagnetic interference capability of the water quality analyzer, the first current limiting resistor and the second current limiting resistor are arranged behind the second piezoresistor and the third piezoresistor, the first current limiting resistor is arranged on an alternating current zero line, and the first current limiting resistor is arranged on an alternating current electric spark line.
Based on the structure of the circuit for improving the anti-electromagnetic interference capability of the water quality analyzer, the discharge gas tube is arranged between the second piezoresistor and the third piezoresistor, and the discharge gas tube is grounded.
Based on the structure of the circuit for improving the anti-electromagnetic interference capability of the water quality analyzer, the filtering protection circuit comprises a first common-mode choke coil, a second common-mode choke coil, a first capacitor, a second capacitor, a third resistor, a fourth piezoresistor and a fifth piezoresistor; the first common-mode choke coil is arranged behind the first current-limiting resistor and the second current-limiting resistor, and two ends of the first common-mode choke coil are respectively connected with the alternating current zero line and the alternating current live wire; the first capacitor and the third resistor are sequentially arranged behind the first common-mode choke coil, and the first capacitor and the third resistor are respectively arranged between the alternating current zero line and the alternating current live wire in parallel.
Based on the structure of the circuit for improving the anti-electromagnetic interference capability of the water quality analyzer, the second common-mode choke coil is arranged behind the third resistor, and two ends of the second common-mode choke coil are respectively connected with the alternating current zero line and the alternating current live wire; the fourth piezoresistor is arranged in the end part of the second common-mode choke coil connected with the alternating current zero line, and the fifth piezoresistor is arranged in the end part of the second common-mode choke coil connected with the alternating current live line; the second capacitor and the third capacitor are connected in series and then are connected between an alternating current zero line and an alternating current live line behind the second common-mode choke coil; the center position of the connection position of the second capacitor and the third capacitor is grounded. To sum up, owing to adopted above-mentioned technical scheme, the beneficial effects of the utility model are that:
1. the scheme is adopted, the power supply enters the converter through the lightning protection circuit and the filter circuit, the anti-interference capacity can be greatly enhanced, the effect of attenuating common-mode interference signals can be achieved through at least 2 common-mode choke coils under the condition that the size of the original design is not changed, only extremely small price is spent, the problems that a display screen is screen-patterned and devices are burnt out are solved, and the overall cost is reduced.
Drawings
Fig. 1 is a schematic structural view of the whole of the present invention;
description of the drawings: 1. a power source; 2. a lightning protection circuit; 3. a filter protection circuit; 4. a converter;
21. a safety element; 22. a first voltage dependent resistor; 23. a second voltage dependent resistor; 24. a third voltage dependent resistor; 25. a first current limiting resistor; 26. a second current limiting resistor; 27. a discharge gas tube; 28. a thermistor; 31. a first common-mode choke coil; 32. a second common-mode choke coil; 33. a first capacitor; 34. a second capacitor; 35. a third capacitor; 36. a third resistor; 37. a fourth varistor; 38. and a fifth voltage dependent resistor.
Detailed Description
All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.
Any feature disclosed in this specification (including any accompanying claims, abstract) may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "left" and "right" are used,
The references to "right" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are merely for convenience of description and simplified description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the invention.
Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, there is defined a first,
A feature of "second" or the like may explicitly or implicitly include one or more of that feature.
As shown in fig. 1, the utility model provides a technical solution:
a circuit for improving the anti-electromagnetic interference capability of a water quality analyzer at least comprises but is not limited to a power supply 1, a lightning protection circuit 2, a filter protection circuit 3 and a converter 4; the power supply 1 is connected with the lightning protection circuit 2, the lightning protection circuit 2 is connected with the filter circuit, the filter protection circuit 3 is connected with the converter 4, and at least 2 common-mode choke coils are arranged in the filter protection circuit 3.
Through the circuit structure, the power supply 1 enters the converter 4 through the lightning protection circuit 2 and the filter circuit, the anti-interference capacity can be greatly enhanced, the scheme can achieve the effect of attenuating common mode interference signals through at least 2 common mode choke coils under the condition of not changing the size of the original design, and meanwhile, only the minimum price is spent, so that the problems of screen splash, device burnout and overall cost are solved.
In the prior art, when a common-mode choke coil is used, the flowing common-mode current cannot be restrained, the common-mode choke coil with large inductance is used, and the problems of large size and high price are caused.
As an example, the lightning protection circuit 2 includes a fuse 21, a first voltage dependent resistor 22, a second voltage dependent resistor 23, a third voltage dependent resistor 24, a first current limiting resistor 25, a second current limiting resistor 26, a discharge gas tube 27 and a thermistor 28; the safety piece 21 is arranged on the alternating current zero line and at the access end of the lightning protection circuit 2; the first varistor 22 is arranged behind the fuse 21 in a position between the ac neutral conductor and the ac live conductor; the thermistor 28 is arranged on the ac zero line behind the first varistor 22; the second varistor 23 and the third varistor 24 are arranged in series after the thermistor 28 in a position between the ac neutral line and the ac live line.
As an example, the first current limiting resistor 25 and the second current limiting resistor 26 are arranged after the second varistor 23 and the third varistor 24, the first current limiting resistor 25 is arranged on the ac zero line, and the first current limiting resistor 25 is arranged on the ac live line.
As an example, the discharge gas tube 27 is disposed between the second varistor 23 and the third varistor 24, and the discharge gas tube 27 is disposed to be grounded.
Based on the above structure, the safety element 21 is used for preventing the short circuit of the whole circuit, the first voltage dependent resistor 22, the second voltage dependent resistor 23 and the third voltage dependent resistor 24 are used for performing overvoltage protection on the lightning protection circuit 2, and the discharge gas tube 27 is used for performing large surge or pulse overvoltage protection on the lightning protection circuit 2; the lightning protection circuit 2 is thermally protected by a thermistor 28.
As an example, the filter protection circuit 3 includes a first common mode choke coil 31, a second common mode choke coil 32, a first capacitor 33, a second capacitor 34, a third capacitor 35, a third resistor 36, a fourth varistor 37, and a fifth varistor 38; the first common-mode choke coil 31 is arranged behind the first current-limiting resistor 25 and the second current-limiting resistor 26, and two ends of the first common-mode choke coil 31 are respectively connected with the alternating-current zero line and the alternating-current live line; the first capacitor 33 and the third resistor 36 are arranged in sequence after the first common-mode choke coil 31, the first capacitor 33 and the third resistor 36 being arranged in parallel between the ac neutral line and the ac hot line, respectively.
The second common-mode choke coil 32 is arranged behind the third resistor 36, and two ends of the second common-mode choke coil 32 are respectively connected with the alternating current zero line and the alternating current live line; a fourth varistor 37 is arranged in the end of the second common-mode choke 32 connected to the ac neutral conductor and a fifth varistor 38 is arranged in the end of the second common-mode choke 32 connected to the ac live conductor.
The second capacitor 34 and the third capacitor 35 are connected in series and then connected between the alternating current neutral wire and the alternating current live wire behind the second common-mode choke coil 32; and is grounded at the center of the junction of the second capacitor 34 and the third capacitor 35.
Based on the above structure, the first common-mode choke coil 31 and the second common-mode choke coil 32 suppress common-mode signals, the first capacitor 33 filters differential-mode signals, the third resistor 36 is a discharge resistor of the first capacitor 33, and the second capacitor 34 and the third capacitor 35 are used for filtering coplanar signals entering the rear power supply 1.
In this embodiment, the converter 4 is an AC/DC converter 4, and the fuse 21 is a fuse.
In the application, the common-mode choke coil is a common-mode interference suppression device taking ferrite as a magnetic core, two coils with the same size and the same number of turns are symmetrically wound on the same ferrite annular magnetic core to form a four-end device, and when common-mode current flows through the common-mode choke coil, the common-mode current can generate a homodromous magnetic field in the coil to increase the inductive reactance of the coil, so that the coil presents high impedance and generates a strong damping effect, and the common-mode current can be attenuated at this time, thereby achieving the purpose of suppressing interference. When the differential mode current flows through the two coils, the magnetic fluxes in the magnetic rings are mutually cancelled, and almost no inductance exists, so that the differential mode current can pass through without attenuation.
When a common-mode choke coil is used, the flowing common-mode current cannot be restrained, the common-mode choke coil with large inductance is used, the problems of large size and high price are caused, the 2-level common-mode choke coil is arranged in the scheme in sequence, the original designed size is not changed, the effect of attenuating common-mode interference signals is achieved, and meanwhile, the problems of screen splash and device burning of the display screen are solved only by spending minimum price.
The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.
Claims (6)
1. The utility model provides an improve water quality analyzer anti-electromagnetic interference ability's circuit which characterized in that: the lightning protection circuit comprises a power supply, a lightning protection circuit, a filter protection circuit and a converter; the power supply is connected with the lightning protection circuit, the lightning protection circuit is connected with the filter circuit, the filter protection circuit is connected with the converter, and at least 2 common-mode choke coils are arranged in the filter protection circuit.
2. The circuit for improving the anti-electromagnetic interference capability of the water quality analyzer, as recited in claim 1, wherein: the lightning protection circuit comprises a safety piece, a first voltage dependent resistor, a second voltage dependent resistor, a third voltage dependent resistor, a first current limiting resistor, a second current limiting resistor, a discharge gas tube and a thermistor; the safety piece is arranged on the alternating current zero line and at the access end of the lightning protection circuit; the first piezoresistor is arranged at a position between the alternating current zero line and the alternating current live line behind the safety element; the thermistor is arranged on an alternating current zero line behind the first piezoresistor; the second piezoresistor and the third piezoresistor are arranged in series at a position between the alternating current zero line and the alternating current live line behind the thermistor.
3. The circuit for improving the anti-electromagnetic interference capability of the water quality analyzer, as recited in claim 2, wherein: the first current limiting resistor and the second current limiting resistor are arranged behind the second voltage dependent resistor and the third voltage dependent resistor, the first current limiting resistor is arranged on an alternating current zero line, and the first current limiting resistor is arranged on an alternating current live wire.
4. The circuit for improving the anti-electromagnetic interference capability of the water quality analyzer, as recited in claim 3, wherein: the discharge gas tube is arranged between the second piezoresistor and the third piezoresistor, and the discharge gas tube is grounded.
5. The circuit for improving the anti-electromagnetic interference capability of the water quality analyzer, as recited in claim 4, wherein: the filter protection circuit comprises a first common-mode choke coil, a second common-mode choke coil, a first capacitor, a second capacitor, a third resistor, a fourth piezoresistor and a fifth piezoresistor; the first common-mode choke coil is arranged behind the first current-limiting resistor and the second current-limiting resistor, and two ends of the first common-mode choke coil are respectively connected with the alternating current zero line and the alternating current live wire; the first capacitor and the third resistor are sequentially arranged behind the first common-mode choke coil, and the first capacitor and the third resistor are respectively arranged between the alternating current zero line and the alternating current live wire in parallel.
6. The circuit for improving the anti-electromagnetic interference capability of the water quality analyzer, as recited in claim 5, wherein: the second common-mode choke coil is arranged behind the third resistor, and two ends of the second common-mode choke coil are respectively connected with the alternating current zero line and the alternating current live wire; the fourth piezoresistor is arranged in the end part of the second common-mode choke coil connected with the alternating current zero line, and the fifth piezoresistor is arranged in the end part of the second common-mode choke coil connected with the alternating current live line; the second capacitor and the third capacitor are connected in series and then are connected between an alternating current zero line and an alternating current live line behind the second common-mode choke coil; the center position of the connection position of the second capacitor and the third capacitor is grounded.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221474002.0U CN218549741U (en) | 2022-06-14 | 2022-06-14 | Circuit for improving anti-electromagnetic interference capability of water quality analyzer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221474002.0U CN218549741U (en) | 2022-06-14 | 2022-06-14 | Circuit for improving anti-electromagnetic interference capability of water quality analyzer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN218549741U true CN218549741U (en) | 2023-02-28 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221474002.0U Active CN218549741U (en) | 2022-06-14 | 2022-06-14 | Circuit for improving anti-electromagnetic interference capability of water quality analyzer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN218549741U (en) |
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2022
- 2022-06-14 CN CN202221474002.0U patent/CN218549741U/en active Active
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