CN114447882A - Circuit local overheating protection trigger circuit and trigger method - Google Patents
Circuit local overheating protection trigger circuit and trigger method Download PDFInfo
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- CN114447882A CN114447882A CN202210150532.8A CN202210150532A CN114447882A CN 114447882 A CN114447882 A CN 114447882A CN 202210150532 A CN202210150532 A CN 202210150532A CN 114447882 A CN114447882 A CN 114447882A
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- circuit
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- temperature sensing
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- 238000013021 overheating Methods 0.000 title claims abstract description 33
- 238000000034 method Methods 0.000 title claims abstract description 28
- 230000001012 protector Effects 0.000 claims abstract description 5
- 238000010292 electrical insulation Methods 0.000 claims description 7
- 230000001960 triggered effect Effects 0.000 abstract description 4
- 238000012423 maintenance Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 13
- 239000004020 conductor Substances 0.000 description 6
- ORQBXQOJMQIAOY-UHFFFAOYSA-N nobelium Chemical compound [No] ORQBXQOJMQIAOY-UHFFFAOYSA-N 0.000 description 5
- 230000007935 neutral effect Effects 0.000 description 4
- 239000003990 capacitor Substances 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- CNQCVBJFEGMYDW-UHFFFAOYSA-N lawrencium atom Chemical compound [Lr] CNQCVBJFEGMYDW-UHFFFAOYSA-N 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000010301 surface-oxidation reaction Methods 0.000 description 1
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H5/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal non-electric working conditions with or without subsequent reconnection
- H02H5/04—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal non-electric working conditions with or without subsequent reconnection responsive to abnormal temperature
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/16—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/26—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
- H02H3/32—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors
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- Emergency Protection Circuit Devices (AREA)
Abstract
The invention discloses a circuit local overheating protection trigger circuit and a trigger method, which are characterized in that the trigger circuit comprises a temperature sensing element and a current limiting element, wherein one end of the temperature sensing element is communicated with a power line, the other end of the temperature sensing element is connected with one end of the current limiting element in series, and the other end of the current limiting element is connected with a grounding wire; the triggering method comprises the steps that a temperature sensing element detects the local temperature of a protected circuit, when the local temperature of the protected circuit is higher than an allowable value, the temperature sensing element is used for switching on the circuit or reducing the resistance value, so that grounding current larger than a set value flows between a power line and a grounding line, and a leakage protector of a preceding-stage circuit or a residual current circuit breaker is triggered to cut off the circuit. The invention can realize the protection triggering of local overheating of the circuit by a simple structure with low production cost and low maintenance cost, and is particularly suitable for solving the problem of overheating protection triggering caused by overlarge local contact resistance of a wiring position, a wiring position of a circuit and a terminal, and a contact point of a plug and a socket in the circuit.
Description
Technical Field
The invention relates to the field of local overheating protection of circuits, in particular to a trigger circuit and a trigger method for local overheating protection of a circuit, which are applied to overheating protection caused by overlarge local contact resistance at a wiring position, a wiring position of a circuit and a terminal, and a contact point of a plug and a socket in the circuit.
Background
Local contact resistance at a wiring position, a wiring position of a line and a terminal, a contact point of a plug and a socket in a circuit is locally overlarge due to loosening or conductor surface oxidation and the like, so that local overheating is caused when load current flows in the circuit, surrounding combustible materials can be ignited, and an electrical fire is caused.
Some existing trigger circuits and trigger methods aiming at local overheating protection of circuits adopt simple temperature switches to realize a trigger function, but a common temperature switch is used for switching on a current limiting or switching off circuit of an electrical load power supply loop and needs to work with current for a long time, and the trigger circuit and other parts of the overheating protection circuit are inseparable, so that the structure is complex; some devices adopt a temperature sensor, and an electronic circuit is used for logical judgment according to the detected local temperature of the circuit, so that an overheat protection triggering function is realized. The traditional circuit overheating protection trigger circuit and the trigger method have the disadvantages of complex realization structure, high cost, limited reliability and unsuitability for wide application.
So far, no literature report and practical application of a local overheating protection trigger circuit and a trigger method of a circuit with low cost, simple structure and small trigger current are seen.
Disclosure of Invention
The invention aims to solve the technical problems that the existing circuit local overheating protection trigger circuit and the trigger method are complex in structure, high in cost, limited in reliability and not suitable for wide application, and provides the circuit local overheating protection trigger circuit and the trigger method which are low in cost, simple in structure and small in trigger current. The trigger circuit and the trigger method are particularly suitable for the local overheating protection of the wiring position, the wiring position of a line and a terminal, and the contact point of a plug and a socket in the circuit.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a trigger circuit for local overheat protection of circuit is composed of a temp sensing element, a current limiting element, a trigger circuit, a current sensing circuit, a current limiting circuit,
1) the temperature sensing element is a temperature switch or a thermistor with a negative temperature coefficient; the current limiting element is an independent resistance element or a capacitance element, or the series connection or the parallel connection of the two elements;
2) when the temperature sensing element is a temperature switch, the temperature sensing element comprises a shell with good electrical insulation and heat conduction and a normally open contact for closing a circuit when the sensed temperature exceeds a limit value; when the temperature sensing element is a thermistor with a negative temperature coefficient, the temperature sensing element comprises a shell with good electrical insulation and heat conduction and the thermistor with the negative temperature coefficient, the resistance value of which is reduced along with the temperature rise;
3) one end of the temperature sensing element is communicated with a power line of a protected circuit, the other end of the temperature sensing element is communicated with one end of the current limiting element in series, the other end of the current limiting element is communicated with the grounding wire, and a shell of the temperature sensing element is tightly attached to or riveted with the local part of the protected circuit in an electrical insulation mode.
The triggering method is characterized in that a temperature sensing element in a circuit local overheating protection triggering circuit detects the local temperature of a protected circuit, when the local temperature of the protected circuit is higher than an allowable value, the temperature sensing element is connected with the circuit or the resistance value is reduced, so that grounding current larger than a set value flows between a power line and a grounding line, and a leakage protector or a residual current circuit breaker of a preceding stage circuit is triggered to cut off the circuit.
The invention has the obvious effects that: the circuit local overheating protection trigger circuit has the advantages of simple structure, small number of components, low cost and high working reliability, can be fixedly installed or used as an accessory for auxiliary installation, and has high insulating strength in an unfired state; the circuit local overheating protection triggering method is simple, easy to implement in engineering, small in triggering current, and free of influence on normal work and service life of a load circuit and electrical equipment, and solves the problems that a traditional circuit local overheating protection triggering circuit and a triggering method are complex, the cost of the triggering circuit is high, the traditional circuit local overheating protection triggering circuit is not suitable for wide application, and the installation mode is not flexible.
Drawings
Fig. 1 is a schematic structural diagram of a local overheat protection trigger circuit according to embodiment 1 of the present invention;
fig. 2 is a schematic diagram of a local overheat protection triggering circuit applied to a socket circuit based on a capacitive element as a current limiting element according to embodiment 2 of the present invention;
fig. 3 is a schematic diagram of a local overheat protection trigger circuit applied to a socket circuit based on a resistive element as a current limiting element according to embodiment 3 of the present invention;
fig. 4 is a schematic diagram of a local overheat protection trigger circuit applied to a socket circuit based on parallel connection of a resistive element and a capacitive element as a current limiting element according to embodiment 4 of the present invention;
fig. 5 is a schematic diagram of a local overheat protection trigger circuit applied to a socket circuit based on a series connection of a resistive element and a capacitive element as a current limiting element according to embodiment 5 of the present invention;
fig. 6 is a schematic diagram of a local overheat protection trigger circuit applied to a terminal circuit based on a capacitive element as a current limiting element according to embodiment 6 of the present invention;
fig. 7 is a schematic diagram of a local overheat protection trigger circuit applied to a terminal circuit based on a resistive element as a current limiting element according to embodiment 7 of the present invention;
fig. 8 is a schematic diagram of a local overheat protection trigger circuit according to embodiment 8 of the present invention, which is based on the application of a parallel connection of a resistive element and a capacitive element as a current limiting element in a terminal circuit;
fig. 9 is a schematic diagram of a local overheat protection trigger circuit according to embodiment 9 of the present invention, which is based on the application of a series connection of a resistive element and a capacitive element as a current limiting element in a terminal circuit;
fig. 10 is a schematic diagram of a local overheat protection trigger circuit applied to a wire-terminal circuit based on a capacitive element as a current-limiting element according to embodiment 10 of the present invention;
fig. 11 is a schematic diagram of a local overheat protection trigger circuit applied to a wire-terminal circuit based on a resistive element as a current-limiting element according to embodiment 11 of the present invention;
fig. 12 is a schematic diagram of a local overheat protection trigger circuit according to embodiment 12 of the present invention, which is based on the application of a parallel connection of a resistive element and a capacitive element as a current limiting element in a wire joint circuit;
fig. 13 is a schematic diagram of a local overheat protection trigger circuit according to embodiment 13 of the present invention, which is based on a series connection of a resistive element and a capacitive element as a current limiting element and is applied to a wire connector circuit.
Detailed Description
The circuit local overheating protection trigger circuit of the present invention is described in detail below with reference to the accompanying drawings and the detailed description.
As shown in fig. 1, a circuit local overheat protection trigger circuit 101 according to embodiment 1 of the present invention includes: a temperature sensing element 102 and a current limiting element 103 connected in series in circuit;
1) the temperature sensing element 102 is a temperature switch or a thermistor with a negative temperature coefficient; the current limiting element 103 is a single resistance element or a capacitance element, or a series connection or a parallel connection of the two;
2) when the temperature sensing element 102 is a temperature switch, it comprises an electrically insulating and well heat-conducting housing and a normally open contact for closing the circuit when the sensed temperature exceeds a limit value; when the temperature sensing element 102 is a negative temperature coefficient thermistor, it includes an electrically insulating and well heat-conducting housing and a negative temperature coefficient thermistor whose resistance value decreases with increasing temperature;
3) one end of the temperature sensing element 102 is communicated with a power line 104 of a protected circuit, the other end of the temperature sensing element is communicated with one end of a current limiting element in series, the other end of the current limiting element is communicated with a grounding wire 105, and a shell of the temperature sensing element is tightly attached or riveted with a local part of the protected circuit in an electrical insulation mode.
The triggering method of the circuit local overheating protection trigger circuit is characterized in that a temperature sensing element in the circuit local overheating protection trigger circuit detects the local temperature of a protected circuit, and when the local temperature of the protected circuit is higher than an allowable value, the temperature sensing element is connected with the circuit or the resistance value is reduced, so that grounding current larger than a set value flows between a power line and a grounding line, and a leakage protector or a residual current circuit breaker of a preceding stage circuit is triggered to cut off the circuit.
As shown in fig. 2, a circuit local overheat protection trigger circuit according to embodiment 2 of the present invention is applied to a socket circuit local overheat protection trigger circuit based on a capacitive element as a current limiting element:
1) in a circuit local overheating protection trigger circuit 200, temperature sensing elements are two temperature switches 203 and 204 with normally open contacts 201 and 202, and electric insulation shells of the two temperature switches are respectively and tightly attached to metal conductors at a live wire jack 206 and a zero wire jack 207 of a socket 205; the two temperature switch contacts are connected in parallel, one end of the circuit is connected to the live wire jack 206 and the live wire 208, and the other end of the circuit is connected to the capacitor element 209; the other end circuit of the capacitive element is connected to the ground jack 210 and to the ground 211; neutral wire 212 connects to the neutral jack 207 of the socket
2) The triggering method comprises the following steps: when the temperature of any one or two metal conductors at the live wire and zero wire jacks of the socket exceeds an allowable value, the normally open contacts inside the temperature switches at the corresponding positions are switched to a circuit closed state, so that the trigger circuit is switched on, the current larger than a set value flows between the live wire and the ground wire, and then the earth leakage protector or the residual current circuit breaker of the pre-stage circuit is triggered to cut off the circuit.
As shown in fig. 3, a circuit local overheat protection trigger circuit according to embodiment 3 of the present invention is applied to a socket circuit local overheat protection trigger circuit based on a resistive element as a current limiting element, and the circuit configuration, connection relationship, and trigger method are the same as those of embodiment 2, except that the current limiting element is a resistive element 213.
As shown in fig. 4, a circuit local overheating protection trigger circuit according to embodiment 4 of the present invention is applied to a socket circuit local overheating protection trigger circuit based on a parallel connection of a resistance element and a capacitance element as a current limiting element, and the circuit configuration, connection relationship, and trigger method are the same as those of embodiments 2 and 3, except that the current limiting element is formed by a parallel connection of a resistance element 213 and a capacitance element 209.
As shown in fig. 5, a circuit local overheat protection trigger circuit according to embodiment 5 of the present invention is applied to a socket circuit local overheat protection trigger circuit based on a series connection of a resistive element and a capacitive element as a current limiting element, and the circuit configuration, connection relationship, and triggering method are the same as those of embodiments 2 and 3, except that the current limiting element is formed by a series connection of a resistive element 213 and a capacitive element 209.
As shown in fig. 6, a circuit local overheat protection trigger circuit according to embodiment 6 of the present invention is applied to a terminal circuit local overheat protection trigger circuit based on a capacitive element as a current limiting element, and the circuit configuration, connection relationship, and trigger method thereof are the same as those in embodiment 2, and in fig. 6, a live wire terminal 301 and a neutral wire terminal 302 of a switch 300 are protected circuit parts.
As shown in fig. 7, a local overheat protection trigger circuit according to embodiment 7 of the present invention is applied to a terminal circuit local overheat protection trigger circuit based on a resistance element as a current limiting element, and the circuit configuration, connection relationship, and trigger method thereof are the same as those in embodiment 3, and in fig. 7, a live wire terminal 301 and a neutral wire terminal 302 of a switch 300 are protected circuit parts.
As shown in fig. 8, a circuit local overheating protection trigger circuit according to embodiment 8 of the present invention is applied to a terminal circuit local overheating protection trigger circuit based on a resistance element and a capacitance element connected in parallel as a current limiting element, and the circuit configuration, connection relationship, and trigger method thereof are the same as those of embodiments 2 and 3, except that the current limiting element is formed by connecting a resistance element 213 and a capacitance element 209 in parallel.
As shown in fig. 9, a circuit local overheat protection trigger circuit according to embodiment 9 of the present invention is applied to a terminal circuit local overheat protection trigger circuit based on a series connection of a resistance element and a capacitance element as a current limiting element, and the circuit configuration, connection relationship, and trigger method are the same as those of embodiments 2 and 3 except that the current limiting element is formed by a series connection of a resistance element 213 and a capacitance element 209.
As shown in fig. 10, a circuit local overheating protection trigger circuit in embodiment 10 of the present invention is based on a capacitor element applied to a conductor tab circuit as a current limiting element, and the circuit configuration, connection relationship, and trigger method thereof are the same as those in embodiments 2 and 3.
As shown in fig. 11, a circuit local overheat protection trigger circuit according to embodiment 11 of the present invention is based on a resistor element applied to a conductor tab circuit as a current limiting element, and the circuit configuration, connection relationship, and triggering method thereof are the same as those of embodiments 2 and 3.
As shown in fig. 12, a circuit local overheat protection trigger circuit according to embodiment 12 of the present invention is based on a current limiting element formed by connecting a resistance element and a capacitance element in parallel, and is applied to a conductor tab circuit local overheat protection trigger circuit, and the circuit configuration, connection relationship, and trigger method are the same as those of embodiments 2 and 3.
As shown in fig. 13, a circuit local overheating protection trigger circuit according to embodiment 13 of the present invention is a circuit local overheating protection trigger circuit applied to a wire-terminal circuit based on a resistance element and a capacitance element connected in series as a current limiting element, and the circuit configuration, connection relationship, and trigger method thereof are the same as those of embodiments 2 and 3.
The embodiments of the present invention are not exhaustive, and those skilled in the art will still fall within the scope of the present invention as claimed without simple duplication and modification by the inventive efforts.
Claims (2)
1. A trigger circuit for local overheat protection of circuit is composed of a temp sensing element, a current limiting element, a trigger circuit, a current sensing circuit, a current limiting circuit,
1) the temperature sensing element is a temperature switch or a thermistor with a negative temperature coefficient; the current limiting element is an independent resistance element or a capacitance element, or the series connection or the parallel connection of the two elements;
2) when the temperature sensing element is a temperature switch, the temperature sensing element comprises a shell with good electrical insulation and heat conduction and a normally open contact for closing a circuit when the sensed temperature exceeds a limit value; when the temperature sensing element is a thermistor with a negative temperature coefficient, the temperature sensing element comprises a shell with good electrical insulation and heat conduction and the thermistor with the negative temperature coefficient, the resistance value of which is reduced along with the temperature rise;
3) one end of the temperature sensing element is communicated with a power line of a protected circuit, the other end of the temperature sensing element is communicated with one end of the current limiting element in series, the other end of the current limiting element is communicated with the grounding wire, and a shell of the temperature sensing element is tightly attached to or riveted with the local part of the protected circuit in an electrical insulation mode.
2. The triggering circuit of claim 1, wherein the triggering method comprises detecting the temperature of the local part of the protected circuit by a temperature sensing element in the triggering circuit of the local overheating protection, and when the temperature of the local part of the protected circuit is higher than an allowable value, the temperature sensing element turns on the circuit or the resistance value is reduced, so that a ground current larger than a set value flows between a power line and a ground line, thereby triggering a leakage protector of a preceding circuit or a residual current circuit breaker to cut off the circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210150532.8A CN114447882A (en) | 2022-02-18 | 2022-02-18 | Circuit local overheating protection trigger circuit and trigger method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210150532.8A CN114447882A (en) | 2022-02-18 | 2022-02-18 | Circuit local overheating protection trigger circuit and trigger method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114447882A true CN114447882A (en) | 2022-05-06 |
Family
ID=81374360
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210150532.8A Withdrawn CN114447882A (en) | 2022-02-18 | 2022-02-18 | Circuit local overheating protection trigger circuit and trigger method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114447882A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102593790A (en) * | 2011-01-05 | 2012-07-18 | 海洋王照明科技股份有限公司 | Lighting fixture overheating protection circuit and lighting fixture thereof |
| CN106953210A (en) * | 2017-03-09 | 2017-07-14 | 陈展天 | The extraordinary path method of autotomying that generates heat of connector |
-
2022
- 2022-02-18 CN CN202210150532.8A patent/CN114447882A/en not_active Withdrawn
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102593790A (en) * | 2011-01-05 | 2012-07-18 | 海洋王照明科技股份有限公司 | Lighting fixture overheating protection circuit and lighting fixture thereof |
| CN106953210A (en) * | 2017-03-09 | 2017-07-14 | 陈展天 | The extraordinary path method of autotomying that generates heat of connector |
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Application publication date: 20220506 |