CN217469457U - Protection circuit for preventing live wire and zero line from being reversely connected - Google Patents
Protection circuit for preventing live wire and zero line from being reversely connected Download PDFInfo
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- CN217469457U CN217469457U CN202121499529.4U CN202121499529U CN217469457U CN 217469457 U CN217469457 U CN 217469457U CN 202121499529 U CN202121499529 U CN 202121499529U CN 217469457 U CN217469457 U CN 217469457U
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Abstract
The utility model discloses a prevent reverse protection circuit who connects of live wire zero line, including voltage acquisition unit, comparing element, reference voltage unit and control switch unit, voltage acquisition unit is used for acquireing the voltage that zero line and ground wire contact or/and shell float between the ground and exports to comparing element's first input, the reference voltage unit is used for exporting reference voltage to comparing element's second input, comparing element's output is connected with control switch unit's drive end electricity, control switch unit is used for establishing ties external circuit. The utility model provides a prevent the reverse protection circuit who connects of live wire zero line, when the zero line was misconnected into the live wire, can export the exact actuating signal, ensure that equipment obtains the protection.
Description
Technical Field
The utility model relates to an electrical safety technical field, specifically speaking relates to a prevent protection circuit of live wire zero line transposition.
Background
In some practical application scenarios where the live wire and the zero wire must be correctly connected, one of the most essential support points for the automatic detection method of whether the live wire and the zero wire are correctly connected is to use the different potential differences between the live wire and the zero wire and the ground wire as basic conditions for identification. However, once the ground wire is connected to the ground, the monitoring system cannot make an effective and accurate judgment.
In the prior art disclosed in chinese patent CN200410077490.1, the whole protection monitoring circuit must rely on the earth connection point "EGND", and when the connection condition of this earth connection point is abnormal, it will directly affect the potential difference between VAC-N and EGND to cause the whole detecting part to fail to work normally, and the executing part cannot be triggered to make a correct response, and the protection mechanism fails. Other similar solutions must rely on good connection of the ground wire, i.e. the ground resistance between the ground wire and the true ground must be sufficiently small.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a prevent protection circuit of live wire zero line transposition, when the zero line was misconnected into the live wire, can export correct actuating signal, ensure that equipment obtains the protection.
The utility model discloses a prevent that protection circuit of live wire zero line transposition adopts's technical scheme is:
the utility model provides a prevent protection circuit of live wire zero line transposition, includes voltage acquisition unit, comparing element, reference voltage unit and control switch unit, voltage acquisition unit is used for obtaining the voltage that zero line and ground wire contact or/and shell float between the ground and exports the first input to comparing element, the reference voltage unit is used for exporting reference voltage to comparing element's second input, comparing element's output is connected with control switch unit's drive end electricity, control switch unit is used for series connection external circuit.
Preferably, the voltage acquisition unit comprises an optical coupler, an input end of the optical coupler is connected in series between a zero line and a ground line junction, and an output end of the optical coupler is electrically connected with a first input end of the comparison unit.
As a preferred scheme, the voltage acquisition unit further comprises a first resistor, a second resistor and a first capacitor, the output end of the optocoupler is a phototriode, the collector of the phototriode is electrically connected with the power supply after being connected with the first resistor in series, one end of the second resistor and one end of the first capacitor after being connected in parallel are respectively electrically connected with the emitter of the phototriode and the first input end of the comparison unit, and the other end of the second resistor and the first capacitor after being connected in parallel is grounded.
Preferably, the reference voltage unit includes a first voltage-dividing resistor and a second voltage-dividing resistor, one end of the first voltage-dividing resistor and one end of the second voltage-dividing resistor after being connected in series are electrically connected to a power supply, the other end of the first voltage-dividing resistor after being connected in series are grounded, and a second input end of the comparing unit is electrically connected between the first voltage-dividing resistor and the second voltage-dividing resistor.
Preferably, the reference voltage unit further includes a second capacitor, one end of the second capacitor is grounded, and the other end of the second capacitor is electrically connected between the first voltage dividing resistor and the second voltage dividing resistor.
Preferably, the comparison unit comprises a comparator.
Preferably, the control switch unit includes a first electronic switch and a relay, the first electronic switch is connected in series with a coil end of the relay, a driving end of the first electronic switch is electrically connected with an output end of the comparison unit, and a contact end of the relay is used for connecting an external circuit in series.
The utility model discloses a prevent that protection circuit of live wire zero line transposition's beneficial effect is: when the zero line is correctly wired, the voltage difference of the zero line to the ground or the floating ground is very small, the voltage signal acquired by the voltage acquisition unit is lower than the reference voltage output by the reference voltage unit, at the moment, the comparison unit normally outputs a low level, and the control switch unit is switched on, so that the external equipment normally operates. When the zero line is misconnected into the live wire, the voltage difference of the zero line to the earth or the floating ground can be obviously increased, the voltage signal acquired by the voltage acquisition unit is higher than the reference voltage output by the reference voltage unit, the comparison unit normally outputs a high level at the moment, and the control switch unit is cut off, so that the external equipment stops running. Through the connection of comparing element and introduction shell floating ground, effectively improve monitoring sensitivity, and can also utilize the voltage signal that the floating ground of shell was connected into the live wire by the mistake to the zero line to accurately listen under the unsettled unfavorable condition of earth connection to have more efficient equipment protection.
Drawings
Fig. 1 is a schematic circuit diagram of the protection circuit for preventing the reverse connection of the live wire and the zero wire.
Detailed Description
The invention will be further elucidated and described with reference to the following embodiments and drawings in which:
referring to fig. 1, the protection circuit for preventing reverse connection of the live line and the zero line includes a voltage acquisition unit, a comparison unit, a reference voltage unit, and a control switch unit. The voltage acquisition unit is used for acquiring the voltage between a zero line and a ground wire connection point or/and the shell floating ground and outputting the voltage to the first input end of the comparison unit, the reference voltage unit is used for outputting reference voltage to the second input end of the comparison unit, the output end of the comparison unit is electrically connected with the driving end of the control switch unit, and the control switch unit is used for being connected with an external circuit in series.
When the zero line is correctly wired, the voltage difference of the zero line to the ground or the floating ground is very small, the voltage signal acquired by the voltage acquisition unit is lower than the reference voltage output by the reference voltage unit, at the moment, the comparison unit normally outputs a low level, and the control switch unit is switched on, so that the external equipment normally operates. When the zero line is misconnected into the live wire, the voltage difference of the zero line to the earth or the floating ground can be obviously increased, the voltage signal acquired by the voltage acquisition unit is higher than the reference voltage output by the reference voltage unit, the comparison unit normally outputs a high level at the moment, and the control switch unit is cut off, so that the external equipment stops running. Through the connection of comparing element and introduction shell floating ground, effectively improve monitoring sensitivity, and can also utilize the voltage signal that the floating ground of shell was connected into the live wire by the mistake to the zero line to accurately listen under the unsettled unfavorable condition of earth connection to have more efficient equipment protection.
In this embodiment, the voltage acquisition unit includes an optical coupler a, an input end of the optical coupler a is connected in series between a zero line and a ground line contact, and an output end of the optical coupler a is electrically connected with a first input end of the comparison unit. The optical coupler is used for collecting voltage information and isolating input and output voltages, so that signal interference is reduced.
Further, the voltage acquisition unit further comprises a first resistor R2, a second resistor R3 and a first capacitor C1, and the output end of the optical coupler is a phototriode. The collector of the phototriode is electrically connected with the power supply after being connected with the first resistor R2 in series, one end of the second resistor R3 and the first capacitor C1 after being connected in parallel is respectively electrically connected with the emitter of the phototriode and the first input end of the comparison unit, and the other end of the phototriode after being connected in parallel is grounded. The first input terminal of the comparison unit is input with a more stable voltage signal through the filtering effect of the first capacitor C1. And the input end of the optical coupler is a light emitting diode, and the series resistor R1 of the optical coupler is connected in series between the neutral line AC _ N and the ground wire connection point E or/and the shell floating ground E1.
In this embodiment, the reference voltage unit includes a first voltage-dividing resistor R4 and a second voltage-dividing resistor R5, one end of the first voltage-dividing resistor R4 and the second voltage-dividing resistor R5 after being connected in series is electrically connected to a power supply, the other end of the first voltage-dividing resistor R5 after being connected in series is grounded, and a second input end of the comparing unit is electrically connected between the first voltage-dividing resistor R4 and the second voltage-dividing resistor R5. The voltage division function of the first voltage division resistor R4 and the second voltage division resistor R5 is utilized, so that a stable reference voltage is output to the second input end of the comparison unit.
Further, the reference voltage unit further includes a second capacitor C2, one end of the second capacitor C2 is grounded, and the other end of the second capacitor C2 is electrically connected between the first voltage dividing resistor and the second voltage dividing resistor. The second input terminal of the comparison unit is input with a more stable voltage signal through the filtering effect of the second capacitor C2.
In this embodiment, the comparing unit includes a comparator B. When the voltage of the non-inverting input terminal of the comparator B is larger than that of the inverting input terminal of the comparator B, the comparator B outputs high level, otherwise, the comparator B outputs low level.
In this embodiment, the control switch unit includes a first electronic switch Q and a relay J, the first electronic switch Q is connected in series with a coil end of the relay J, a driving end of the first electronic switch Q is electrically connected with an output end of the comparison unit B, and a contact end of the relay J is used for connecting an external circuit in series. Specifically, the first electronic switch Q is a PNP triode, and when the comparator outputs a low level, the first electronic switch Q is turned on, so that the relay J works normally, and the contact end of the relay J is closed. When the comparator outputs a high level, the first electronic switch Q is turned off, so that the relay J stops operating and the contact terminal thereof is opened.
It should be finally noted that the above embodiments are only intended to illustrate the technical solutions of the present invention, and not to limit the scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention can be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention.
Claims (7)
1. The utility model provides a prevent protection circuit of live wire zero line transposition, its characterized in that, includes voltage acquisition unit, comparing element, reference voltage unit and control switch unit, voltage acquisition unit is used for obtaining the voltage that zero line and ground wire contact or/and shell float between the ground and exports to comparing element's first input end, reference voltage unit is used for exporting reference voltage to comparing element's second input end, comparing element's output and control switch unit's drive end electricity are connected, control switch unit is used for external circuit of establishing ties.
2. The protection circuit for preventing the reverse connection of the live wire and the neutral wire as claimed in claim 1, wherein the voltage acquisition unit comprises an optocoupler, an input end of the optocoupler is connected in series between the neutral wire and the ground wire contact, and an output end of the optocoupler is electrically connected with the first input end of the comparison unit.
3. The protection circuit for preventing the reverse connection of the live wire and the zero wire as claimed in claim 2, wherein the voltage acquisition unit further comprises a first resistor, a second resistor and a first capacitor, the output end of the optocoupler is a phototransistor, the collector of the phototransistor is connected in series with the first resistor and then electrically connected with the power supply, one end of the second resistor and the first capacitor after being connected in parallel is respectively electrically connected with the emitter of the phototransistor and the first input end of the comparison unit, and the other end of the second resistor and the first capacitor after being connected in parallel is grounded.
4. The protection circuit for preventing reverse connection of a live wire and a neutral wire as claimed in claim 1, wherein the reference voltage unit comprises a first voltage-dividing resistor and a second voltage-dividing resistor, one end of the first voltage-dividing resistor and the second voltage-dividing resistor connected in series is electrically connected to a power supply, the other end of the first voltage-dividing resistor and the second voltage-dividing resistor connected in series is grounded, and the second input end of the comparison unit is electrically connected between the first voltage-dividing resistor and the second voltage-dividing resistor.
5. The protection circuit for preventing reverse connection of a live wire and a neutral wire of claim 4, wherein the reference voltage unit further comprises a second capacitor, one end of the second capacitor is grounded, and the other end of the second capacitor is electrically connected between the first voltage dividing resistor and the second voltage dividing resistor.
6. The protection circuit for preventing reverse connection of a live wire and a neutral wire of claim 1, wherein the comparison unit comprises a comparator.
7. The protection circuit for preventing reverse connection of a live wire and a neutral wire as claimed in claim 1, wherein the control switch unit comprises a first electronic switch and a relay, the first electronic switch is connected in series with a coil end of the relay, a driving end of the first electronic switch is electrically connected with an output end of the comparison unit, and a contact end of the relay is used for connecting an external circuit in series.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121499529.4U CN217469457U (en) | 2021-06-29 | 2021-06-29 | Protection circuit for preventing live wire and zero line from being reversely connected |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121499529.4U CN217469457U (en) | 2021-06-29 | 2021-06-29 | Protection circuit for preventing live wire and zero line from being reversely connected |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217469457U true CN217469457U (en) | 2022-09-20 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202121499529.4U Active CN217469457U (en) | 2021-06-29 | 2021-06-29 | Protection circuit for preventing live wire and zero line from being reversely connected |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217469457U (en) |
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2021
- 2021-06-29 CN CN202121499529.4U patent/CN217469457U/en active Active
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