CN211351689U - Leakage protection circuit - Google Patents
Leakage protection circuit Download PDFInfo
- Publication number
- CN211351689U CN211351689U CN202020302880.9U CN202020302880U CN211351689U CN 211351689 U CN211351689 U CN 211351689U CN 202020302880 U CN202020302880 U CN 202020302880U CN 211351689 U CN211351689 U CN 211351689U
- Authority
- CN
- China
- Prior art keywords
- resistor
- operational amplifier
- capacitor
- grounded
- circuit
- 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
- Amplifiers (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
The utility model provides an earth leakage protection circuit, include: the circuit comprises a zero sequence transformer, a resistor R428, a capacitor C481, a resistor R481, a 2-level amplifying circuit and a comparison circuit; one end of a resistor R428 is connected with one end of a secondary coil of the zero sequence transformer, and the other end of the resistor R428 is connected with the 2-level amplifying circuit; one end of the capacitor C481 is connected with one end of a secondary coil of the zero sequence transformer, and the other end of the capacitor C is grounded; one end of the resistor R481 is connected with one end of a secondary coil of the zero sequence transformer, and the other end of the resistor R is grounded; the other end of the secondary coil of the zero sequence transformer is grounded; the 2-stage amplifying circuit is connected with the comparison circuit. The power supply has the advantages that when the leakage fault occurs, the 220v output can be cut off in time, and the personal and property safety of a user is effectively protected.
Description
Technical Field
The utility model relates to an earth leakage protection circuit.
Background
The output of the inverter is 220v, which is a strong current. The inverter without the leakage protection circuit threatens the safety of people and property if the inverter leaks electricity when meeting water and moisture or one of the inverters has electric leakage.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the problem of providing an electric leakage protection circuit, which realizes the electric leakage protection function, and can cut off the output of 220v in time when the electric leakage fault occurs, thereby effectively protecting the personal and property safety of users; the defects of the prior art are overcome.
The utility model provides an earth leakage protection circuit, include: the circuit comprises a zero sequence transformer, a resistor R428, a capacitor C481, a resistor R481, a 2-level amplifying circuit and a comparison circuit; one end of a resistor R428 is connected with one end of a secondary coil of the zero sequence transformer, and the other end of the resistor R428 is connected with the 2-level amplifying circuit; one end of the capacitor C481 is connected with one end of a secondary coil of the zero sequence transformer, and the other end of the capacitor C is grounded; one end of the resistor R481 is connected with one end of a secondary coil of the zero sequence transformer, and the other end of the resistor R is grounded; the other end of the secondary coil of the zero sequence transformer is grounded; the 2-stage amplifying circuit is connected with the comparison circuit.
The utility model provides an earth leakage protection circuit has such characteristic: the internal power supply includes: the 2-stage amplifying circuit includes: a capacitor C483, a resistor R483, a capacitor C484, a resistor R484, an operational amplifier U490A, a resistor R486, a capacitor C486, a resistor R485, a resistor R487, an operational amplifier U490B, a capacitor C488, a resistor R488, a capacitor C489, a resistor R489, a capacitor C485 and a capacitor C487; one end of the resistor R483 is connected with the first voltage end, and the other end of the resistor R483 is connected with the other end of the resistor R428; one end of the capacitor C483 is connected with the first voltage end, and the other end is grounded; one end of the resistor R484 is connected to the other end of the resistor R428, and the other end is connected to the positive input of the operational amplifier U490A; one end of the capacitor C484 is connected with the other end of the resistor R428, and the other end is grounded; one end of the capacitor C486 is connected with the negative input end of the operational amplifier U490A, and the other end is connected with the output end of the operational amplifier U490A; one end of the resistor R486 is connected with the negative input end of the operational amplifier U490A, and the other end is connected with the output end of the operational amplifier U490A; one end of the resistor R485 is connected with the negative input end of the operational amplifier U490A, and the other end is grounded; one end of the resistor R487 is connected to the output end of the operational amplifier U490A, and the other end is connected to the negative input end of the operational amplifier U490B; one end of the capacitor C488 is connected with the negative input end of the operational amplifier U490B, and the other end is connected with the output end of the operational amplifier U490B; one end of the resistor R488 is connected with the negative input end of the operational amplifier U490B, and the other end is connected with the output end of the operational amplifier U490B; one end of the capacitor C489 is connected to the positive input end of the operational amplifier U490B, and the other end is grounded; one end of the resistor R489 is connected to the positive input end of the operational amplifier U490B, and the other end is connected to the first voltage end; one end of the capacitor C485 is connected with the output end of the operational amplifier U490B, and the other end is grounded; one end of the capacitor C487 is connected with the output end of the operational amplifier U490B, and the other end is grounded; the output of the operational amplifier U490B is connected to a comparison circuit.
The utility model provides a leakage protection circuit can also have such characteristic: the 2-stage amplification circuit further includes: a capacitor C490 and a resistor R490; one end of the resistor R490 is connected with one voltage end of the operational amplifier U490A, and the other end is connected with a second voltage; one end of the capacitor C490 is connected to a voltage terminal of the operational amplifier U490A, and the other end is connected to ground.
The utility model provides a leakage protection circuit can also have such characteristic: operational amplifier U490A, operational amplifier U490B are model LM 2904.
The utility model provides a leakage protection circuit can also have such characteristic: the comparison circuit includes: an operational amplifier U491A, a resistor R492, a resistor R493, a resistor R494 and a capacitor C494; one end of the resistor R492 is connected with the negative input end of the operational amplifier U491A, and the other end is connected with the second voltage end; one end of the resistor R493 is connected with the negative input end of the operational amplifier U491A, and the other end of the resistor R493 is grounded; one end of the resistor R494 is connected with the output end of the operational amplifier U491A, and the other end is connected with the 2-stage amplifying circuit; the capacitor C494 is connected with the 2-stage amplifying circuit, and the other end of the capacitor C is grounded; the positive input terminal of the operational amplifier U491A is connected with a 2-stage amplification circuit.
The utility model provides a leakage protection circuit can also have such characteristic: the comparison circuit further includes: a resistor R491 and a capacitor C491; one end of the resistor R491 is connected with one voltage end of the operational amplifier U491A, and the other end is connected with a second voltage end; one end of the capacitor C491 is connected with one voltage end of the operational amplifier, and the other end is grounded; the other voltage terminal of the operational amplifier U491A is connected to ground.
The utility model provides a leakage protection circuit can also have such characteristic: the operational amplifier U491A is of type TSV912 AIDT.
Drawings
Fig. 1 is a schematic diagram of an embodiment of a leakage protection circuit.
The specific implementation mode is as follows:
the present invention will be further described with reference to the accompanying drawings and specific embodiments.
As shown in fig. 1, the leakage protection circuit includes: the circuit comprises a zero sequence transformer, a resistor R428, a capacitor C481, a resistor R481, a 2-level amplifying circuit and a comparison circuit.
One end of the resistor R428 is connected with one end of the secondary coil of the zero sequence transformer, and the other end is connected with the 2-stage amplifying circuit. One end of the capacitor C481 is connected with one end of the secondary coil of the zero sequence transformer, and the other end is grounded. One end of the resistor R481 is connected with one end of a secondary coil of the zero sequence transformer, and the other end of the resistor R is grounded. The other end of the secondary coil of the zero sequence transformer is grounded. The 2-stage amplifying circuit is connected with the comparison circuit.
The 2-stage amplifying circuit includes: the circuit comprises a capacitor C483, a resistor R483, a capacitor C484, a resistor R484, an operational amplifier U490A, a capacitor C490, a resistor R486, a capacitor C486, a resistor R485, a resistor R487, an operational amplifier U490B, a capacitor C488, a resistor R488, a capacitor C489, a resistor R489, a capacitor C485 and a capacitor C487.
One end of the resistor R483 is connected to the first voltage terminal A2.5V, and the other end is connected to the other end of the resistor R428. Capacitor C483 has one end connected to first voltage terminal A2.5V and the other end connected to ground. The resistor R484 is connected at one end to the other end of the resistor R428 and at the other end to the positive input of the operational amplifier U490A. The capacitor C484 has one end connected to the other end of the resistor R428 and the other end connected to ground. Capacitor C486 has one end connected to the negative input of operational amplifier U490A and the other end connected to the output of operational amplifier U490A. Resistor R486 has one end connected to the negative input terminal of operational amplifier U490A and the other end connected to the output terminal of operational amplifier U490A. One end of the resistor R485 is connected with the negative input end of the operational amplifier U490A, and the other end is grounded. One end of the resistor R490 is connected to a voltage end of the operational amplifier U490A, and the other end is connected to a second voltage A5V. One end of the capacitor C490 is connected to a voltage terminal of the operational amplifier U490A, and the other end is connected to ground.
Resistor R487 has one end connected to the output of operational amplifier U490A and the other end connected to the negative input of operational amplifier U490B. The capacitor C488 has one end connected to the negative input terminal of the operational amplifier U490B and the other end connected to the output terminal of the operational amplifier U490B. Resistor R488 is connected to the negative input of operational amplifier U490B at one end and to the output of operational amplifier U490B at the other end. One end of the capacitor C489 is connected to the positive input of the operational amplifier U490B, and the other end is grounded. The resistor R489 has one end connected to the positive input terminal of the operational amplifier U490B and the other end connected to the first voltage terminal A2.5V. One end of the capacitor C485 is connected with the output end of the operational amplifier U490B, and the other end is grounded. One end of the capacitor C487 is connected to the output terminal of the operational amplifier U490B, and the other end is grounded. The output of the operational amplifier U490B is connected to a comparison circuit. The output of the operational amplifier U490B is also connected to the E _ LEAK terminal.
The comparison circuit includes: operational amplifier U491A, resistance R492, resistance R493, resistance R494, electric capacity C494, resistance R491, electric capacity C491.
One end of the resistor R492 is connected to the negative input terminal of the operational amplifier U491A, and the other end is connected to the second voltage terminal A5V. One end of the resistor R493 is connected to the negative input terminal of the operational amplifier U491A, and the other end is grounded. The resistor R494 is connected to the output terminal of the operational amplifier U491A at one end and to the 2-stage amplification circuit, i.e., to the output terminal of the operational amplifier U490B at the other end. The capacitor C494 is connected with the 2-stage amplification circuit, namely, the output end of the operational amplifier U490B, and the other end is grounded. The positive input of the operational amplifier U491A is connected to the 2-stage amplification circuit, i.e. to the output of the operational amplifier U490B. One end of the resistor R491 is connected with one voltage end of the operational amplifier U491A, and the other end is connected with the second voltage end A5V. One end of the capacitor C491 is connected with one voltage end of the operational amplifier, and the other end is grounded. The other voltage terminal of the operational amplifier U491A is connected to ground.
In this embodiment, the operational amplifiers U490A and U490B are LM 2904. The operational amplifier U491A is of type TSV912 AIDT.
The utility model provides a leakage protection circuit's theory of operation: the two lines AC1 and AC2 are AC lines, 220 v. The 2 lines pass through a magnetic ring of the zero sequence transformer, a secondary coil of the zero sequence transformer is in a certain proportion to a primary coil, when electric leakage occurs, the currents of the AC1 and the AC2 are not equal, and the currents are induced in the secondary coil. The induced current forms voltage through a resistor R481, passes through a resistor R482, reaches a position between R483 and R484, the total voltage is increased by 2.5v, then passes through primary amplification, reaches a pin 1 of U490A, then passes through a resistor R487, reaches a negative input end of U490B, is amplified again, an amplified signal comes out from an output end of U490B, passes through a comparison circuit after coming out from the output end, is compared with a rated voltage, exceeds a comparison value, generates a high level at the output end of U491A, enters a single chip microcomputer, and is subjected to shutdown protection.
The above, only be the concrete implementation of the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art is in the technical scope of the present invention, according to the technical solution of the present invention and the utility model, the concept of which is equivalent to replace or change, should be covered within the protection scope of the present invention.
Claims (7)
1. An earth leakage protection circuit, characterized in that: the method comprises the following steps: the circuit comprises a zero sequence transformer, a resistor R428, a capacitor C481, a resistor R481, a 2-level amplifying circuit and a comparison circuit;
one end of the resistor R428 is connected with one end of a secondary coil of the zero sequence transformer, and the other end of the resistor R428 is connected with the 2-level amplifying circuit; one end of the capacitor C481 is connected with one end of a secondary coil of the zero sequence transformer, and the other end of the capacitor C is grounded; one end of the resistor R481 is connected with one end of a secondary coil of the zero sequence transformer, and the other end of the resistor R is grounded; the other end of the secondary coil of the zero sequence transformer is grounded; the 2-stage amplifying circuit is connected with the comparison circuit.
2. The earth leakage protection circuit of claim 1, wherein:
wherein, 2 grades of amplifier circuit includes: a capacitor C483, a resistor R483, a capacitor C484, a resistor R484, an operational amplifier U490A, a resistor R486, a capacitor C486, a resistor R485, a resistor R487, an operational amplifier U490B, a capacitor C488, a resistor R488, a capacitor C489, a resistor R489, a capacitor C485 and a capacitor C487;
one end of the resistor R483 is connected with the first voltage end, and the other end of the resistor R483 is connected with the other end of the resistor R428; one end of the capacitor C483 is connected with the first voltage end, and the other end is grounded; one end of the resistor R484 is connected to the other end of the resistor R428, and the other end is connected to the positive input of the operational amplifier U490A; one end of the capacitor C484 is connected with the other end of the resistor R428, and the other end is grounded; one end of the capacitor C486 is connected with the negative input end of the operational amplifier U490A, and the other end is connected with the output end of the operational amplifier U490A; one end of the resistor R486 is connected with the negative input end of the operational amplifier U490A, and the other end is connected with the output end of the operational amplifier U490A; one end of the resistor R485 is connected with the negative input end of the operational amplifier U490A, and the other end is grounded;
one end of the resistor R487 is connected to the output end of the operational amplifier U490A, and the other end is connected to the negative input end of the operational amplifier U490B; one end of the capacitor C488 is connected with the negative input end of the operational amplifier U490B, and the other end is connected with the output end of the operational amplifier U490B; one end of the resistor R488 is connected with the negative input end of the operational amplifier U490B, and the other end is connected with the output end of the operational amplifier U490B; one end of the capacitor C489 is connected to the positive input end of the operational amplifier U490B, and the other end is grounded; one end of the resistor R489 is connected to the positive input end of the operational amplifier U490B, and the other end is connected to the first voltage end; one end of the capacitor C485 is connected with the output end of the operational amplifier U490B, and the other end is grounded; one end of the capacitor C487 is connected with the output end of the operational amplifier U490B, and the other end is grounded; the output of the operational amplifier U490B is connected to a comparison circuit.
3. The earth leakage protection circuit of claim 2, wherein:
wherein, 2 grades of amplifier circuit still includes: a capacitor C490 and a resistor R490;
one end of the resistor R490 is connected with one voltage end of the operational amplifier U490A, and the other end is connected with a second voltage; one end of the capacitor C490 is connected to a voltage terminal of the operational amplifier U490A, and the other end is connected to ground.
4. The earth leakage protection circuit of claim 2, wherein:
the model of the operational amplifier U490A and the model of the operational amplifier U490B are LM 2904.
5. The earth leakage protection circuit of claim 1, wherein:
wherein, the comparison circuit includes: an operational amplifier U491A, a resistor R492, a resistor R493, a resistor R494 and a capacitor C494;
one end of the resistor R492 is connected with the negative input end of the operational amplifier U491A, and the other end is connected with the second voltage end; one end of the resistor R493 is connected with the negative input end of the operational amplifier U491A, and the other end of the resistor R493 is grounded; one end of the resistor R494 is connected with the output end of the operational amplifier U491A, and the other end is connected with the 2-stage amplifying circuit; the capacitor C494 is connected with the 2-stage amplifying circuit, and the other end of the capacitor C is grounded; the positive input terminal of the operational amplifier U491A is connected with a 2-stage amplification circuit.
6. The leakage protection circuit of claim 5, wherein:
wherein, the comparison circuit still includes: a resistor R491 and a capacitor C491;
one end of the resistor R491 is connected with one voltage end of the operational amplifier U491A, and the other end is connected with a second voltage end; one end of the capacitor C491 is connected with one voltage end of the operational amplifier, and the other end is grounded; the other voltage terminal of the operational amplifier U491A is connected to ground.
7. The leakage protection circuit of claim 5, wherein:
the model of the operational amplifier U491A is TSV912 AIDT.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020302880.9U CN211351689U (en) | 2020-03-12 | 2020-03-12 | Leakage protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020302880.9U CN211351689U (en) | 2020-03-12 | 2020-03-12 | Leakage protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211351689U true CN211351689U (en) | 2020-08-25 |
Family
ID=72101663
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020302880.9U Active CN211351689U (en) | 2020-03-12 | 2020-03-12 | Leakage protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211351689U (en) |
-
2020
- 2020-03-12 CN CN202020302880.9U patent/CN211351689U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN211351689U (en) | Leakage protection circuit | |
| CN101651325A (en) | Electric leakage detection protector | |
| EP4080706A1 (en) | Excess-energy protection circuit, residual current device, electronic apparatus and distribution box | |
| CN201270408Y (en) | Detection and protection apparatus for leakage | |
| CN205103301U (en) | Hourglass current detection circuit who restraines common mode interference | |
| CN103236679A (en) | Electronic type backup protection device for AC (alternating current) circuit breaker | |
| CN201378730Y (en) | Power circuit breaker protective circuit | |
| CN107276030A (en) | A kind of safety electric shock-prevention socket circuit | |
| CN207399036U (en) | A kind of low-power consumption DC offset voltage generation circuit for photoionization detector | |
| CN207765941U (en) | A kind of earth leakage protective device | |
| CN209709668U (en) | A kind of earth leakage protective device having ground wire missing protection | |
| CN204992530U (en) | Three -phase leakage protection circuit | |
| IE850214L (en) | Residual current device | |
| CN208608715U (en) | The leak current fault monitoring chip of earth leakage protective device | |
| CN221353909U (en) | Leakage protection circuit | |
| CN109818332A (en) | A kind of earth leakage protective device having ground wire missing protection | |
| CN212085800U (en) | Electric leakage protector based on single chip microcomputer | |
| CN100435443C (en) | Intelligent leakage protector | |
| CN201204436Y (en) | Electrical leakage detection protection device for solar photovoltaic parallel inverter | |
| CN207542771U (en) | Electric power leakage circuit breakers | |
| CN209896685U (en) | Open central line leakage protection circuit | |
| CN221530969U (en) | Leakage protection circuit | |
| CN211556848U (en) | Leakage protection device | |
| CN213398876U (en) | Grounding detection circuit and electrical appliance | |
| CN214281228U (en) | Phase-shift protection control system of single-phase alternating-current power supply |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |