CN214176890U

CN214176890U - Electric leakage protection circuit and gold melting furnace

Info

Publication number: CN214176890U
Application number: CN202120223641.9U
Authority: CN
Inventors: 张雷; 李晔炜
Original assignee: Shenzhen Fasttobuy Business Co ltd
Current assignee: Shenzhen Fasttobuy Business Co ltd
Priority date: 2021-01-26
Filing date: 2021-01-26
Publication date: 2021-09-10
Anticipated expiration: 2031-01-26

Abstract

The application discloses earth leakage protection circuit and melting furnace, establish current transformer through the cover on the input and the output at power supply circuit, and be connected current transformer and temperature controller electricity, if the phenomenon of electric leakage appears in the heating load, power supply circuit's electric current changes, the electric current changes the back, current transformer's magnetic flux phi also changes along with the current change, current transformer can send signal to the temperature controller, then the disconnection of temperature controller control relay, thereby cut off whole power supply circuit, play the effect of protecting human safety, avoid melting each electrical components of furnace and burnt out.

Description

Electric leakage protection circuit and gold melting furnace

Technical Field

The utility model belongs to the technical field of the golden manufacturing of melting, especially, relate to an earth leakage protection circuit and melting gold stove.

Background

The metal melting furnace is a furnace specially used for melting gold, and comprises an intermediate frequency power supply cabinet and a furnace body, the application range in industry is wide, and the existing small industrial grade electric heating metal melting furnace has the possibility of electric leakage if a resistance wire is contacted with a base layer at the outermost circle during heating, so that the metal melting furnace has certain harm to a human body and also has influence on the heating process of the metal melting furnace, and the heating time is prolonged. In summary, in order to eliminate such risks, the gold melting furnace needs to be provided with a leakage protection circuit, the leakage relay is relatively large at present, the leakage relay is installed in the controller box and has more production requirements, the price of the leakage relay is more expensive than that of a common relay, the operation is inconvenient, and a miniaturized circuit capable of performing leakage protection is needed at the moment.

SUMMERY OF THE UTILITY MODEL

Objects of the invention

In order to overcome the above insufficiency, the utility model aims to provide an electric leakage protection circuit and melting furnace to solve current melting furnace and need install leakage relay, leakage relay is bulky, occupies melting furnace more space, leads to melting the whole volume increase of furnace, and leakage relay is expensive, has increased user's expenditure cost's technical problem.

(II) technical scheme

To achieve the above object, an aspect of the present application provides a leakage protection circuit, including: the power supply circuit, the heating load, the relay, a temperature sensor, temperature controller and current transformer, heating load and relay are established ties in power supply circuit, the temperature controller is connected with the relay electricity and is used for controlling relay actuation or disconnection, temperature sensor is connected with heating load and temperature controller electricity, a heating temperature that is used for real-time detection heating load and with the heating temperature conveying that detects to the temperature controller, with judge whether heating load reaches predetermined heating value, current transformer cover locates power supply circuit's input and output and be connected with the temperature controller electricity, be used for sending signal to the temperature controller when sensing power supply circuit's current and changing, make the disconnection of temperature controller control relay, power supply circuit's current change is by what heating load electric leakage led to.

This application is through the current transformer is established to the cover on the input and the output of power supply circuit, and carry out the electricity with current transformer and temperature controller and be connected, if the phenomenon of electric leakage appears in the heating load, when heating load and shell contact promptly, the input current of power supply circuit is different with transmission current, the electric current changes the back, current transformer's magnetic flux phi also changes along with current variation, current transformer can send signal to the temperature controller, then the disconnection of temperature controller control relay, thereby cut off whole power supply circuit, play the effect of protection human safety, avoid melting each electrical components of gold stove to be burnt out, and, because current transformer is small with low costs, can reduce the whole volume of melting gold stove, reduce the manufacturing cost of melting gold stove.

In some embodiments, the heating load is a resistive wire.

The utility model discloses an on the other hand provides a melt gold stove, and electrical heating melts gold stove has foretell earth leakage protection circuit, through setting up earth leakage protection circuit, plays the human safety of protection, and each electrical components of protection melts gold stove can not burn out the effect, can also reduce the whole volume of melting gold stove, reduces the manufacturing cost of melting gold stove.

Drawings

Fig. 1 is a simple structure diagram of the leakage protection circuit 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 will be described in detail with reference to the accompanying drawings. It should be understood that the description is intended to be illustrative only and is not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.

The utility model provides a pair of leakage protection circuit, include: the power supply circuit, heating load 2, relay 1, temperature sensor 4, temperature controller 3 and current transformer, heating load 2 and relay 1 establish ties in power supply circuit, temperature controller 3 is connected with relay 1 electricity and is used for controlling actuation or disconnection of relay 1, temperature sensor 4 is connected with heating load 2 and temperature controller 3 electricity, a heating temperature for real-time detection heating load 2 and with the heating temperature conveying that detects to temperature controller 3, with judge whether heating load 2 reaches predetermined heating value, current transformer cover locates power supply circuit's input and output and be connected with temperature controller 3 electricity, be used for sending the turn-off signal to temperature controller 3 when the electric current that senses power supply circuit changes, make temperature controller 3 control relay 1 break, the current change of power supply circuit is by what heating load 2 electric leakage led to.

Specifically, the heating load 2 is a resistance wire.

Specifically, the current transformer is of an annular structure, the input end and the output end of the power supply loop directly penetrate through the middle of the current transformer, and the signal output end of the current transformer is connected with the temperature controller 3.

Specifically, the temperature controller 3 is internally provided with a single chip microcomputer, and the current transformer is connected with an IO port of the single chip microcomputer.

Specifically, set up two binding post in the relay 1, connect power supply circuit's input (live wire) and output (zero line) respectively, still connect controlled switch on the binding post, controlled switch is controlled by temperature controller 3, when current transformer sensed power supply circuit's electric current and changed, current transformer exports a voltage and gives the data acquisition IO port to temperature controller 3 singlechips, the singlechip stops according to this voltage to relay 1 output voltage, make the unable actuation work of controlled switch in the relay 1, the power supply circuit disconnection.

The working principle of the leakage protection circuit is as follows:

when the metal melting furnace normally works, an operator sets a metal melting temperature to the temperature controller 3, the temperature controller 3 sends current to the relay 1 after receiving the temperature, the relay 1 is attracted, a power supply loop is connected, the resistance wire is heated, the temperature sensor 4 detects the temperature of the resistance wire and feeds back the actual temperature of the resistance wire to the temperature controller 3 in real time, after the heating temperature of the resistance wire reaches a set value, the temperature controller 3 controls the resistance wire to maintain the temperature, the current algebraic sum of the input and output of the same node is 0 according to kirchhoff law at the moment, the input end and the output end of the power supply loop are the same in current size but opposite in direction, namely Iin Iout, and Ip is 0.

When the electric leakage condition of the metal melting furnace occurs, namely, a resistance wire is in contact with a shell, Iin is not equal to Iout, and a leakage current Ip is not equal to 0, after the current in the circuit is changed, the magnetic flux phi of a current transformer also changes along with the change of the current in the circuit, the current transformer can feed detected numerical values back to an IO port of the temperature controller 3 in a voltage mode, and the temperature controller 3 selectively disconnects the relay 1 according to the voltage collected by the IO collection port of the single chip microcomputer to cut off a power supply loop.

This application on the other hand provides a melting furnace, this electrical heating melting furnace has set up foretell earth leakage protection circuit, melting furnace is equipped with the crucible from inside to outside in proper order, the zone of heating, thermal-insulated heat preservation and basic unit, set up heating load 2 in the earth leakage protection circuit in the zone of heating, temperature sensor 4 sets up on the outer wall of crucible, the top of melting furnace body is provided with the bell, temperature controller 3 sets up in melting furnace below, temperature controller 3 includes liquid crystal display and operating keyboard.

When the metal melting furnace works, the temperature controller 3 receives an external signal (namely a set temperature value), sends current to control the relay 1 to be closed, and the resistance wire of the internal heating layer is heated, so that metal placed in the crucible is melted.

The leakage protection circuit is arranged, so that the safety of a human body is protected, the electric elements of the metal melting furnace are protected from being burnt out, the whole volume of the metal melting furnace can be reduced, and the manufacturing cost of the metal melting furnace is reduced.

It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explaining the principles of the invention and are not to be construed as limiting the invention. Therefore, any modification, equivalent replacement, improvement and the like made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. Further, it is intended that the appended claims cover all such variations and modifications as fall within the scope and boundaries of the appended claims or the equivalents of such scope and boundaries.

Claims

1. An earth leakage protection circuit, comprising: the heating device comprises a power supply loop, a heating load (2), a relay (1), a temperature sensor (4), a temperature controller (3) and a current transformer, wherein the heating load (2) and the relay (1) are connected in series in the power supply loop, the temperature controller (3) is electrically connected with the relay (1) and used for controlling the relay (1) to be attracted or disconnected, the temperature sensor (4) is electrically connected with the heating load (2) and the temperature controller (3) and used for detecting the heating temperature of the heating load (2) in real time and transmitting the detected heating temperature to the temperature controller (3) so as to judge whether the heating load (2) reaches a preset heating value or not, the current transformer is sleeved at the input end and the output end of the power supply loop and electrically connected with the temperature controller (3) and used for sending a disconnection signal to the temperature controller (3) when the current of the power supply loop is sensed to change, and enabling the temperature controller (3) to control the relay (1) to be switched off, wherein the current change of the power supply loop is caused by the electric leakage of the heating load (2).

2. The leakage protection circuit according to claim 1, wherein the heating load (2) is a resistance wire.

3. A furnace for melting gold, characterized in that it has a leakage protection circuit according to any of the preceding claims 1-2.