阅读说明：本技术 过温保护开关插座、过温保护电路及其控制方法 (Over-temperature protection switch socket, over-temperature protection circuit and control method thereof ) 是由 蔡峰毅 许海恩 苏金土 陈金环 于 2021-08-03 设计创作，主要内容包括：本发明涉及电子电路领域,尤其是涉及一种在单位时间内采集多个温度点的数据在进行分析判断以保护的过温保护开关插座、过温保护电路及其控制方法,具有稳定性更好、精确性更高、有更高的智能化、温度可调节等优点。所述过温保护电路包括漏电保护单元及过温保护单元；所述过温保护单元包括集成电路U2、热敏电阻Rt1、Rt2及集成电路U3；其利用集成电路U2及U3配合,实现于单位时间内进行多个温度点的数据的采集,再通过U3对这些采集的温度点的数据进行分析,当温度值达到设定值时,集成电路U3输出稳定可靠信号使可控硅导通,脱扣器TK动作。(The invention relates to the field of electronic circuits, in particular to an over-temperature protection switch socket, an over-temperature protection circuit and a control method thereof, wherein the over-temperature protection switch socket and the over-temperature protection circuit are used for collecting data of a plurality of temperature points in unit time and analyzing and judging the data to protect the data. The over-temperature protection circuit comprises a leakage protection unit and an over-temperature protection unit; the over-temperature protection unit comprises an integrated circuit U2, thermistors Rt1, Rt2 and an integrated circuit U3; the integrated circuit U2 and the integrated circuit U3 are matched to realize the collection of data of a plurality of temperature points in unit time, the collected data of the temperature points are analyzed through the U3, and when the temperature value reaches a set value, the integrated circuit U3 outputs a stable and reliable signal to enable a thyristor to be conducted and the release TK to act.)

1. The control method of the over-temperature protection circuit is characterized in that: the method comprises the following steps:

the leakage protection unit is connected with an external power supply and electric equipment;

a leakage protection integrated circuit U4 in the leakage protection unit acquires a leakage signal through a zero sequence current transformer ZCT, and when leakage occurs, the leakage protection integrated circuit U4 outputs a protection signal;

the over-temperature protection unit is connected with the leakage protection integrated circuit U4 and the silicon controlled rectifier SCR;

an integrated circuit U3 in the over-temperature protection unit acquires an over-temperature signal through thermistors Rt1 and Rt2, the integrated circuit U3 compares and processes a plurality of temperature point data collected in unit time, and when the over-temperature occurs, the integrated circuit U3 outputs a protection signal;

the protection signal switches on the SCR, the release TK acts, and the power supply is cut off.

2. The method for controlling the over-temperature protection circuit according to claim 1, wherein: the thermistors Rt1 and Rt2 are both NTC;

collecting a plurality of temperature point data within 1ms-1s, and then taking an average temperature value of the plurality of temperature point data, wherein the average temperature value enables voltage values at two ends of each NTC to change, and when the change value of the voltage value reaches a preset voltage threshold value, the integrated circuit U3 outputs a protection signal.

3. The method for controlling the over-temperature protection circuit according to claim 1, wherein: when the sum of the current vectors of the primary coil of the zero sequence current transformer ZCT is not zero, the secondary coil of the zero sequence current transformer ZCT generates induced voltage to generate the leakage signal.

4. Excess temperature protection circuit, its characterized in that: the leakage protection circuit comprises a leakage protection unit and an over-temperature protection unit, wherein the leakage protection unit comprises a zero sequence current transformer ZCT, a leakage protection integrated circuit U4, a silicon controlled rectifier SCR and a release TK which are connected, the leakage protection integrated circuit U4 is connected with a control electrode of the silicon controlled rectifier SCR through a node A, and the leakage protection integrated circuit U4 comprises a zero sequence current transformer ZCT, a leakage protection integrated circuit U4, a silicon controlled rectifier SCR and a release TK, wherein:

the over-temperature protection unit comprises an integrated circuit U2, thermistors Rt1, Rt2 and an integrated circuit U3, wherein the integrated circuit U3 is a single chip microcomputer U3;

the thermistor Rt1 is connected in series with the resistor R6, and the thermistor Rt2 is connected in series with the resistor R7 to form a first temperature control resistor and a second temperature control resistor respectively; the first temperature control resistor and the second temperature control resistor are connected in parallel between the Vout end and the GND end of the integrated circuit U2, the Vin end of the integrated circuit U2 is connected with the anode of the Silicon Controlled Rectifier (SCR) after being connected with the resistor R4 in series, and the first temperature control resistor and the second temperature control resistor are connected in parallel between the VDD end and the VSS end of the integrated circuit U3; one end of the thermistor Rt1, which is connected with the resistor R6, is connected with the P0.0 end of the integrated circuit U3, one end of the thermistor Rt2, which is connected with the resistor R7, is connected with the P0.1 end of the integrated circuit U3, and the P1.1 end of the integrated circuit U3 is connected with the node A after being connected with the diode D5 in series;

the GND terminal of the integrated circuit U2 and the VSS terminal of the integrated circuit U3 are both grounded, and the P1.1 terminal and the VSS terminal of the integrated circuit U3 are connected in parallel with the resistor R8 and the capacitor C6.

5. The over-temperature protection circuit according to claim 4, wherein: the integrated circuit U2 is a voltage regulator integrated circuit U2, a polar electrolytic capacitor C3 and a capacitor C4 are connected in parallel between the Vout end and the GND end of the integrated circuit U2, and a polar electrolytic capacitor C2 and a voltage regulator diode D4 are connected in series between the Vin end and the GND end of the integrated circuit U2.

6. The over-temperature protection circuit according to claim 4, wherein: the zero sequence current transformer ZCT is sleeved on a live wire L and a zero wire N before the Load, one end of a secondary coil of the zero sequence current transformer ZCT is connected with an RC11 end of the leakage protection integrated circuit U4 after being connected with a resistor R11 in series, and the other end of the secondary coil is connected with an RC12 end of the leakage protection integrated circuit U4 after being connected with a resistor R12 in series; the RC12 terminal and the RC11 terminal of the leakage protection integrated circuit U4 are connected with a capacitor C9 in parallel;

two ends of a secondary coil of the zero sequence current transformer ZCT are connected with a resistor R10 and a capacitor C8 in parallel;

an RC12 end and a GND end of the leakage protection integrated circuit U4 are connected with a capacitor C11 in parallel, an RC11 end and a GND end of the leakage protection integrated circuit U4 are connected with a capacitor C10 in parallel, a DLY end and a GND end of the leakage protection integrated circuit U4 are connected with a capacitor C7 in parallel, and the GND end of the leakage protection integrated circuit U4 is a ground end;

the TRIG end of the leakage protection integrated circuit U4 is connected with the node A after being sequentially connected with the resistor R9 and the diode D6 in series;

the node A is connected with a control electrode of the Silicon Controlled Rectifier (SCR), the anode of the Silicon Controlled Rectifier (SCR) is connected with a resistor R3 in series and then connected with the VDD end of the leakage protection integrated circuit U4, and the cathode of the Silicon Controlled Rectifier (SCR) is grounded;

a resistor R5 and a capacitor C1 are connected in parallel between the control electrode of the silicon controlled rectifier SCR and the ground wire;

a voltage stabilizing diode D3 and a polar capacitor C5 are connected in parallel between the resistor R3 and the GND end connected with the leakage protection integrated circuit U4;

two contact switches of the release TK are respectively connected on the live line L and the zero line N in series; one control input end of the release TK is connected with a live wire L, the other control input end of the release TK is connected with one middle end of a bridge rectifier diode, and the other middle end of the bridge rectifier diode is connected with a zero line;

the anode of the bridge rectifier diode is connected with the anode of the silicon controlled rectifier SCR, and the cathode of the bridge rectifier diode is grounded.

7. The over-temperature protection circuit according to claim 6, wherein: one end of a primary coil of the zero sequence current transformer ZCT is connected with the live wire L, and the other end of the primary coil is sequentially connected with a key AJ and a resistor R1 in series to be connected with the zero line N; one end of a primary coil of the zero sequence current transformer ZCT is sequentially connected with a diode D1, a resistor R2 and a light emitting diode D2 in series and then connected with a zero line N.

8. The over-temperature protection circuit according to claim 6, wherein: and a voltage dependent resistor MOV is also connected between the live wire L and the zero wire N.

9. Excess temperature protection switch socket, its characterized in that: it includes base, face lid, three electrode plug bushes and three electrode socket, the base is with the cooperation assembly of face lid, wherein:

the face cover is provided with three jacks, the three jacks are assembled with the three-electrode plug bushes, and the three-electrode plug bushes are matched and spliced with the three-electrode socket;

the base is provided with a mounting cavity, the over-temperature protection circuit of any one of claims 4 to 8 is mounted in the mounting cavity, and the over-temperature protection unit in the over-temperature protection circuit is arranged in the three-electrode plug bush;

and thermistors Rt1 and Rt2 in the over-temperature protection unit are arranged close to a zero line plug bush and a live line plug bush in the three-electrode plug bush.

Technical Field

The invention relates to the field of electronic circuits, in particular to an over-temperature protection switch socket, an over-temperature protection circuit and a control method thereof, wherein the over-temperature protection switch socket collects data of a plurality of temperature points in unit time and performs analysis and judgment to protect the data.

Background

The electrical appliances with various functions are more and more, people can hardly leave various electrical appliances, and along with the increasing popularization of the electrical appliances, the chances of electrical contact between people and the electrical appliances are more and more, in order to ensure that users can be better protected, the current power supply loops of a plurality of electrical appliances are provided with the leakage protection units, when electrical equipment leaks electricity, or the human body is in electric shock or the equipment is in insulation damage, the leakage protection units can automatically cut off the power supply within dozens of milliseconds, so that the users are prevented from being harmed by the electric shock, and the life safety and property safety of the users are protected; however, when the external temperature is too high, the plug is in poor contact, or the power of the load electrical appliance is too high, the temperature of the leakage protector is too high, the protection function of the leakage protector is influenced to a certain extent, and potential safety hazards exist when the electrical appliance is used.

However, most of the existing over-temperature protection circuits realize over-temperature protection by using the cooperation of a thermistor, a thyristor and a shedding device, and the over-temperature protection mode is as follows: or directly trigger the silicon controlled rectifier thereby control the release, or protect with fortune mode of putting, it is not good and stability subalternation not to have the temperature accuracy mostly to these modes of current to excess temperature protection.

Therefore, how to design an over-temperature protection circuit capable of achieving better stability and higher accuracy is one of the important technical problems to be solved by those skilled in the art.

Disclosure of Invention

The invention aims to provide an over-temperature protection circuit which collects data of a plurality of temperature points in unit time and performs analysis and judgment to protect the data.

In order to achieve the purpose, the invention adopts the following technical scheme:

a control method of an over-temperature protection circuit comprises the following steps:

the leakage protection unit is connected with an external power supply and electric equipment;

a leakage protection integrated circuit U4 in the leakage protection unit acquires a leakage signal through a zero sequence current transformer ZCT, and when leakage occurs, the leakage protection integrated circuit U4 outputs a protection signal;

the over-temperature protection unit is connected with the leakage protection integrated circuit U4 and the silicon controlled rectifier SCR;

an integrated circuit U3 in the over-temperature protection unit acquires an over-temperature signal through thermistors Rt1 and Rt2, the integrated circuit U3 compares and processes a plurality of temperature point data collected in unit time, and when the over-temperature occurs, the integrated circuit U3 outputs a protection signal;

the protection signal switches on the SCR, the release TK acts, and the power supply is cut off.

Further preferred is: the thermistors Rt1 and Rt2 are both NTC;

the over-temperature signal is obtained by collecting a plurality of temperature point data within 1ms-1s, and then taking an average temperature value of the plurality of temperature point data, wherein the average temperature value enables voltage values at two ends of each NTC to change, and when the variation value of the voltage value reaches a preset voltage threshold value, the integrated circuit U3 outputs a protection signal.

Further preferred is: when the sum of the current vectors of the primary coil of the zero sequence current transformer ZCT is not zero, the secondary coil of the zero sequence current transformer ZCT generates induced voltage to generate the leakage signal.

An over-temperature protection circuit comprises an electric leakage protection unit and an over-temperature protection unit, wherein the electric leakage protection unit comprises a zero sequence current transformer ZCT, an electric leakage protection integrated circuit U4, a Silicon Controlled Rectifier (SCR) and a release TK which are connected, the electric leakage protection integrated circuit U4 is connected with a control electrode of the Silicon Controlled Rectifier (SCR) through a node A, and the over-temperature protection circuit comprises:

the over-temperature protection unit comprises an integrated circuit U2, thermistors Rt1, Rt2 and an integrated circuit U3, wherein the integrated circuit U3 is a single chip microcomputer U3;

the thermistor Rt1 is connected in series with the resistor R6, and the thermistor Rt2 is connected in series with the resistor R7 to form a first temperature control resistor and a second temperature control resistor respectively; the first temperature control resistor and the second temperature control resistor are connected in parallel between the Vout end and the GND end of the integrated circuit U2, the Vin end of the integrated circuit U2 is connected with the anode of the Silicon Controlled Rectifier (SCR) after being connected with the resistor R4 in series, and the first temperature control resistor and the second temperature control resistor are connected in parallel between the VDD end and the VSS end of the integrated circuit U3; one end of the thermistor Rt1, which is connected with the resistor R6, is connected with the P0.0 end of the integrated circuit U3, one end of the thermistor Rt2, which is connected with the resistor R7, is connected with the P0.1 end of the integrated circuit U3, and the P1.1 end of the integrated circuit U3 is connected with the node A after being connected with the diode D5 in series;

the GND terminal of the integrated circuit U2 and the VSS terminal of the integrated circuit U3 are both grounded, and the P1.1 terminal and the VSS terminal of the integrated circuit U3 are connected in parallel with the resistor R8 and the capacitor C6.

Further preferred is: the integrated circuit U2 is a voltage regulator integrated circuit U2, a polar electrolytic capacitor C3 and a capacitor C4 are connected in parallel between the Vout end and the GND end of the integrated circuit U2, and a polar electrolytic capacitor C2 and a voltage regulator diode D4 are connected in series between the Vin end and the GND end of the integrated circuit U2.

Further preferred is: the P1.1 terminal and the VSS terminal of the integrated circuit U3 are connected in parallel with the resistor R8 and the capacitor C6.

Further preferred is: the zero sequence current transformer ZCT is sleeved on a live wire L and a zero wire N before the Load, one end of a secondary coil of the zero sequence current transformer ZCT is connected with an RC11 end of the leakage protection integrated circuit U4 after being connected with a resistor R11 in series, and the other end of the secondary coil is connected with an RC12 end of the leakage protection integrated circuit U4 after being connected with a resistor R12 in series; the RC12 terminal and the RC11 terminal of the leakage protection integrated circuit U4 are connected with a capacitor C9 in parallel;

and a resistor R10 and a capacitor C8 are connected in parallel at two ends of a secondary coil of the zero sequence current transformer ZCT.

Further preferred is: an RC12 end and a GND end of the leakage protection integrated circuit U4 are connected with a capacitor C11 in parallel, an RC11 end and a GND end of the leakage protection integrated circuit U4 are connected with a capacitor C10 in parallel, a DLY end and a GND end of the leakage protection integrated circuit U4 are connected with a capacitor C7 in parallel, and the GND end of the leakage protection integrated circuit U4 is a ground end;

the TRIG end of the leakage protection integrated circuit U4 is connected with the node A after being sequentially connected with the resistor R9 and the diode D6 in series.

Further preferred is: the node A is connected with a control electrode of the Silicon Controlled Rectifier (SCR), the anode of the Silicon Controlled Rectifier (SCR) is connected with a resistor R3 in series and then connected with the VDD end of the leakage protection integrated circuit U4, and the cathode of the Silicon Controlled Rectifier (SCR) is grounded;

and a resistor R5 and a capacitor C1 are connected between the control electrode of the silicon controlled rectifier SCR and the ground wire in parallel.

Further preferred is: a voltage stabilizing diode D3 and a polar capacitor C5 are connected in parallel between the resistor R3 and the GND end of the leakage protection integrated circuit U4.

Further preferred is: two contact switches of the release TK are respectively connected on the live line L and the zero line N in series; one control input end of the release TK is connected with a live wire L, the other control input end of the release TK is connected with one middle end of a bridge rectifier diode, and the other middle end of the bridge rectifier diode is connected with a zero line.

Further preferred is: the anode of the bridge rectifier diode is connected with the anode of the silicon controlled rectifier SCR, and the cathode of the bridge rectifier diode is grounded.

Further preferred is: one end of a primary coil of the zero sequence current transformer ZCT is connected with the live wire L, and the other end of the primary coil is sequentially connected with a key AJ and a resistor R1 in series to be connected with the zero line N; one end of a primary coil of the zero sequence current transformer ZCT is sequentially connected with a diode D1, a resistor R2 and a light emitting diode D2 in series and then connected with a zero line N.

Further preferred is: and a voltage dependent resistor MOV is also connected between the live wire L and the zero wire N.

The utility model provides an excess temperature protection switch socket, includes base, face lid, three electrode plug bushes and three electrode socket, base and face lid cooperation assembly, wherein:

the face cover is provided with three jacks, the three jacks are assembled with the three-electrode plug bushes, and the three-electrode plug bushes are matched and spliced with the three-electrode socket;

the base is provided with an installation cavity, the over-temperature protection circuit is installed in the installation cavity, and the over-temperature protection unit in the over-temperature protection circuit is arranged in the three-electrode plug bush;

and thermistors Rt1 and Rt2 in the over-temperature protection unit are arranged close to a zero line plug bush and a live line plug bush in the three-electrode plug bush.

After adopting the technical scheme, compared with the background technology, the invention has the following advantages:

according to the invention, the data of a plurality of temperature points are acquired in unit time by matching the integrated circuits U2 and U3, the acquired data of the temperature points are analyzed by the U3, and when the temperature value reaches a set value, the integrated circuit U3 outputs a stable and reliable signal to switch on the SCR and the release TK acts, so that the intelligent temperature control circuit has the advantages of better stability, higher accuracy, higher intellectualization, adjustable temperature and the like.

Drawings

FIG. 1 is a schematic circuit diagram of the over-temperature protection circuit in an embodiment of the present invention;

fig. 2 is a schematic structural diagram of the over-temperature protection switch socket according to the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are all based on the orientation or positional relationship shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the apparatus or element of the present invention must have a specific orientation, and thus, should not be construed as limiting the present invention.

Examples

As shown in fig. 1, the present invention discloses an over-temperature protection circuit, which includes a leakage protection unit and an over-temperature protection unit.

As shown in fig. 1, the leakage protection unit includes a zero sequence current transformer ZCT, a leakage protection integrated circuit U4, a thyristor SCR, and a release TK, which are connected, and the leakage protection integrated circuit U4 is connected to a control electrode of the thyristor SCR through a node a; the leakage protection integrated circuit U4 is a chip with the model number FM 2147B. Of course, in other embodiments, the leakage protection ic U4 may be another type or specially made leakage protection ic U4 having the same or equivalent function and structure as the FM2147B, which can be easily implemented by those skilled in the art and will not be described in detail.

As shown in fig. 1, the leakage protection unit is an a-type leakage protection unit, when a load leaks electricity, or a human body gets an electric shock or an equipment is damaged by insulation, when a sum of current vectors of a primary coil of a zero-sequence current transformer ZCT is not zero, a secondary coil of the zero-sequence current transformer ZCT generates an induced voltage, the induced voltage is compared and processed by an integrated circuit U4, and when a residual current reaches a setting action current value, a stable and reliable protection signal is output from the integrated circuit U4, the protection signal turns on a silicon controlled rectifier SCR, a release TK acts, and a power cut-off function plays a role in leakage and electric shock protection, the a-type leakage indexes include AC type, pulsating direct current (0 degree, 90 degree, 135 degree), and 6mA smooth direct current, and the specific description of the leakage protection unit is as follows:

as shown in fig. 1, the zero sequence current transformer ZCT cover is established live wire L and zero line N before Load, live wire L with it has the piezo-resistor MOV still to connect between the zero line N for avoid live wire L and zero line N surge voltage, avoid thunderbolt and damage the Load.

As shown in fig. 1, one end of a primary coil of the zero sequence current transformer ZCT is connected to the live line L, and the other end is sequentially connected in series with a key AJ and a resistor R1 to the zero line N; one end of a primary coil of the zero sequence current transformer ZCT is also connected with a zero line N after being sequentially connected with a diode D1, a resistor R2 and a light emitting diode D2 in series; specifically, the method comprises the following steps: one end of the primary coil is sequentially connected with the anode of a diode D1, then connected with the cathode of a diode D1 and connected with a resistor R2, and then connected with the anode of a light-emitting diode D2, and the cathode of the light-emitting diode D2 is connected with a zero line N to form a light-emitting unit which is used for indicating the normal work of a load connected with a power supply and indicating correct wiring;

one end of a secondary coil of the zero sequence current transformer ZTC is connected with the RC11 end of the leakage protection integrated circuit U4 after being connected with the resistor R11 in series, and the other end of the secondary coil is connected with the RC12 end of the leakage protection integrated circuit U4 after being connected with the resistor R12 in series; the RC12 terminal and the RC11 terminal of the leakage protection integrated circuit U4 are connected with a capacitor C9 in parallel; two ends of a secondary coil of the zero sequence current transformer ZCT are connected with a resistor R10 and a capacitor C8 in parallel;

an RC12 end and a GND end of the leakage protection integrated circuit U4 are connected with a capacitor C11 in parallel, an RC11 end and a GND end of the leakage protection integrated circuit U4 are connected with a capacitor C10 in parallel, a DLY end and a GND end of the leakage protection integrated circuit U4 are connected with a capacitor C7 in parallel (the capacitance of the C7 is 300 nf), and a GND end of the leakage protection integrated circuit U4 is a ground end; the TRIG end of the leakage protection integrated circuit U4 is connected with the node A after being sequentially connected with the resistor R9 and the diode D6 in series; specifically, the method comprises the following steps: the TRIG of the earth leakage protection integrated circuit U4 is connected with the anode of the diode D6 after being connected with the resistor R9, and the cathode of the diode D6 is connected with the node A.

As shown in fig. 1, the node a is connected to a control electrode of the SCR, after an anode of the SCR is connected in series with the resistor R3, the node a is connected to a VDD terminal of the leakage protection integrated circuit U4, and a cathode of the SCR is grounded; and a resistor R5 and a capacitor C1 are connected between the control electrode of the silicon controlled rectifier SCR and the ground wire in parallel. A voltage stabilizing diode D3 and a polar capacitor C5 are connected in parallel between the resistor R3 and the GND end connected with the leakage protection integrated circuit U4; specifically, the method comprises the following steps: the anode of the polar capacitor C5 is connected with one end of a resistor R3, and the cathode of the voltage stabilizing diode D3 is connected with one end of a resistor R3.

As shown in fig. 1, two contact switches of the release TK are respectively connected in series to a live line L and a neutral line N; one control input end of the release TK is connected with a live wire L, the other control input end of the release TK is connected with one middle end of a bridge rectifier diode, and the other middle end of the bridge rectifier diode is connected with a zero line. The anode of the bridge rectifier diode is connected with the anode of the silicon controlled rectifier SCR, and the cathode of the bridge rectifier diode is grounded.

As shown in fig. 1, the over-temperature protection unit includes an integrated circuit U2, thermistors Rt1, Rt2 and an integrated circuit U3; the integrated circuit U3 is a single-chip microcomputer type control processing circuit and can acquire temperature data in unit time, and the integrated circuit U3 is a KF8F203 chip. Of course, in other embodiments, the leakage protection integrated circuit U3 may be another type or specially made integrated circuit U3 having the same or equivalent function and structure as the KF8F203, which can be easily implemented by those skilled in the art and will not be described in detail.

As shown in fig. 1, the thermistor Rt1 is connected in series with the resistor R6, and the thermistor Rt2 is connected in series with the resistor R7 to form a first temperature-controlled resistor and a second temperature-controlled resistor respectively;

the GND end of the integrated circuit U2 is a grounding end, the first temperature control resistor and the second temperature control resistor are connected in parallel between the Vout end and the GND end of the integrated circuit U2, and the Vin end of the integrated circuit U2 is connected with the anode of the SCR after being connected with the resistor R4 in series; specifically, the method comprises the following steps: one end of the resistor R6 and the resistor R7 is connected with the Vout end of the integrated circuit U2, and the thermistors Rt1 and Rt2 are connected with the GND end of the integrated circuit U2;

a polar electrolytic capacitor C3 and a capacitor C4 are connected in parallel between the Vout end and the GND end of the integrated circuit U2, and a polar electrolytic capacitor C2 and a voltage stabilizing diode D4 are connected in parallel between the Vin end and the GND end of the integrated circuit U2; specifically, the method comprises the following steps: the Vout end of the integrated circuit U2 is connected with the anode of a polar electrolytic capacitor C3, and the GND end of the integrated circuit U2 is connected with the cathode of a polar electrolytic capacitor C3.

As shown in fig. 1, the VSS terminal of the integrated circuit U3 is a ground terminal, and the first and second temperature-controlled resistors are connected in parallel between the VDD terminal and the VSS terminal of the integrated circuit U3; specifically, the method comprises the following steps: VDD of the integrated circuit U3 is connected with one end of the resistor R6 and the resistor R7, VSS of the integrated circuit U3 is connected with the thermistors Rt1 and Rt 2; one end of the thermistor Rt1, which is connected with the resistor R6, is connected with the P0.0 end of the integrated circuit U3, one end of the thermistor Rt2, which is connected with the resistor R7, is connected with the P0.1 end of the integrated circuit U3, the P1.1 end of the integrated circuit U3 is connected with the anode of the diode D5 in series, and the cathode of the diode D5 is connected with the node A; the P1.1 terminal and the VSS terminal of the integrated circuit U3 are connected in parallel with the resistor R8 and the capacitor C6.

As shown in fig. 1, in the over-temperature protection unit, when the temperature of the live wire or the zero wire at the circuit or the load end is too high, the temperature is sensed by the thermistor, the higher the temperature is, the lower the resistance value of the thermistor is, the voltage applied to two ends of the thermistor is reduced, the voltage is processed by the integrated circuit U3, when the temperature value reaches a set value, a stable and reliable protection signal is output from the integrated circuit U3, the protection signal turns on the silicon controlled rectifier SCR, the release TK operates, and the power supply is cut off to play a role of over-temperature protection, and the thermistors Rt1 and Rt2 are both NTC thermistors, that is: the higher the temperature, the lower the resistance.

The control method of the over-temperature protection circuit comprises the following steps:

the leakage protection unit is connected with an external power supply and electric equipment;

a leakage protection integrated circuit U4 in the leakage protection unit acquires a leakage signal through a zero sequence current transformer ZCT, and when leakage occurs, the leakage protection integrated circuit U4 outputs a protection signal;

the over-temperature protection unit is connected with the leakage protection integrated circuit U4 and the silicon controlled rectifier SCR;

an integrated circuit U3 in the over-temperature protection unit acquires an over-temperature signal through thermistors Rt1 and Rt2, the integrated circuit U3 compares and processes a plurality of temperature point data collected in unit time, and when the over-temperature occurs, the integrated circuit U3 outputs a protection signal;

the protection signal switches on the SCR, the release TK acts, and the power supply is cut off.

It should be noted that: the thermistors Rt1 and Rt2 are both NTC, and the unit time is generally within 1ms-1 s;

the over-temperature signal is obtained by collecting a plurality of temperature point data within 1ms-1s, and then taking an average temperature value of the plurality of temperature point data, wherein the average temperature value enables voltage values at two ends of each NTC to change, and when the variation value of the voltage value reaches a preset voltage threshold value, the integrated circuit U3 outputs a protection signal; and when the sum of the current vectors of the primary coil of the zero sequence current transformer ZCT is not zero, the secondary coil of the zero sequence current transformer ZCT generates induced voltage to generate the leakage signal.

It should be noted that: 1. the integrated circuit U2 is a voltage regulator integrated circuit U2; 2. the integrated circuit U3 is a singlechip U3, and the working principle is as follows: when the integrated circuit U3 detects the work of the over-temperature protection unit, the integrated circuit U3 is influenced by temperature change through the thermistors Rt1 and Rt2, after the resistance value is changed, data of a plurality of temperature points are collected in unit time, the collected data are analyzed through the integrated circuit U3, and whether a protection electric signal is output or not to the silicon controlled rectifier SCR is judged; 3. the protective signals output by the creepage integrated circuit U4 and the integrated circuit U3 can both conduct the SCR, thereby controlling the release TK, an iron core in a coil of the release TK pulls the release plate to separate the pull rod from the release plate, and the movable contact leaves the stationary contact to cut off the power supply of the control release TK.

As shown in fig. 2, an over-temperature protection switch socket includes a base 101, a face cover 102, a three-electrode plug bush, and a three-electrode socket, wherein the base 101 and the face cover 102 are assembled in a matching manner.

The face cover 102 is provided with three jacks, three-hole protective doors 103 are further arranged in the three jacks, and the three-electrode plug bush is in matched insertion connection with the three-electrode socket 104; the three-electrode plug bush comprises a zero line plug bush 105, a live line plug bush 106 and a ground wire plug bush 107; the three jacks are provided with the three-electrode plug bushes;

the base 101 is provided with a mounting cavity, the over-temperature protection circuit is mounted in the mounting cavity, the over-temperature protection unit 108 in the over-temperature protection circuit is arranged in the three-electrode plug bush, and the thermistors Rt1 and Rt2 in the over-temperature protection unit are arranged close to the zero line plug bush 105 and the live line plug bush 106 in the three-electrode plug bush, so that the thermistors Rt1 and Rt2 can better sense the temperature change of the contact piece;

specifically, the method comprises the following steps: the face cover 102 is provided with two through holes, a T key and an ON key are respectively arranged in the two through holes, and transparent silica gel caps are sleeved ON the T key and the ON key; the ON key is connected with a tripping plate in the tripper TK through a pull rod, two ends of the tripping plate are respectively connected with a zero line static sheet and a movable elastic sheet, the fixed end of the movable elastic sheet is arranged ON a base 109, the elastic end of the movable elastic sheet is contacted with a fire line static sheet, and a tripping plate of the tripper TK is arranged at the fixed end of a tripping coil; the base is also provided with a zero sequence current transformer ZCT, and the base 109 is mounted on a substrate 110.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.