KR200267634Y1 - Thermal-cut-off varistor - Google Patents

Abstract

The present invention relates to a thermal cutoff varistor, in particular, to prevent the varistor itself and the downstream electrical appliance from being burned out or exploded when an overcurrent or surge current occurs, the thermally soluble alloy is melted and pulled by a tension spring, which is broken and broken. It is related with the varistor which can cut off automatically. The thermal cutoff varistor includes a base body, two electrodes attached on two sides of the base body, a thermally soluble alloy installed in an insulating tube and a conductor connected to a tension spring, wherein the thermally soluble alloy has a varistor with an overcurrent or surge current. It can melt to break to cut off the current of the power supply as it passes through, and the tension spring can pull the thermally soluble alloy to break immediately when the thermally soluble alloy melts by overcurrent.

Description

Thermal Cutoff Varistors {THERMAL-CUT-OFF VARISTOR}

The present invention relates to a thermal cutoff varistor, in particular a current of the power supply automatically by thermal cutoff control to prevent the varistor itself and the downstream electrical appliance from being exhausted or exploded when an overcurrent or surge current passes through the varistor. It is related with the varistor which can cut off.

The conventional protection circuit A is composed of a fuse B and a transient voltage surge absorber C for protecting the circuit against overvoltage as shown in Fig. 1A. However, the quality of conventional fuses B can be affected by ambient moisture or dust, which is why tripping off to protect circuits and downstream mechanisms when overcurrent or surge currents pass through fuse B. (tripped-off). The conventional transient voltage surge absorber C is parallel to the protection circuit as shown in Fig. 1B, and the resistance value of the transient voltage surge absorber C prevents the overvoltage limit voltage of the protection circuit from occurring when the transient voltage occurs. In order to achieve the transient voltage surge absorber (C) it can be reduced to flow the transient voltage. However, the conventional transient voltage surge absorber C may be damaged or exhausted by generating a high temperature when the overcurrent or surge current passes through the transient voltage surge absorber C. In addition, US Pat. No. 4,652,964 to Botho Ziegenbein discloses a varistor fuse component for protecting an electrical circuit against overvoltage, the varistor fuse component comprising a thermal fuse (D) and a varistor (E). A varistor (E) combined with a thermal fuse (D) for tripping a thermal fuse with Julian or resistive heat loss, first and second conductors (F, G) for supplying current to the fuse component, and the varistor And first and second switch contacts (H, I) connected to each one of the conductors for bridging and bridging, the contacts (H, I) having a thermal fuse (D) as shown in FIG. It is closed when tripped by. However, the varistor fuse component may be exhausted when an overcurrent or surge current passes through the varistor fuse component.

The main object of the present invention is to provide a thermal cutoff varistor, and a varistor capable of automatically cutting off the current of the power supply by thermal cutoff control to protect the varistor itself and the downstream electric appliance, especially when an overcurrent or surge current passes through the varistor. It is about. The thermal cutoff varistor includes a base body, a conductor, and two electrodes attached respectively to the front side and the rear side of the base body, the conductors being connected to a thermally soluble alloy and a tension spring installed in an insulating tube, The thermally soluble alloy can melt to break to cut off the current of the power supply when an overcurrent or surge current passes through the varistor, and the tension spring also pulls the thermally soluble alloy so that the thermally soluble alloy immediately breaks when melted by overcurrent. Can be.

Another object of the present invention is to provide a base body, two electrodes attached on two sides of the base body, and a conductor and a first conductor connected to one of the electrodes to form an AC input line and an AC output line, respectively, A thermal cutoff varistor comprising a second conductor connected to another electrode to form a line, which allows the varistor to absorb the overvoltage of the power supply or to cut off the current when an overcurrent or surge current occurs. It can be connected in parallel to the protection circuit.

The drawings show preferred embodiments of the invention and modes of operation, and in some figures the same or similar parts are designated by the same reference numerals.

1A and 1B are a plan view and a circuit diagram of a conventional transient voltage surge absorber.

2 is a plan view of a thermal fuse component of US Pat. No. 4,652,964.

Figure 3 is a plan view showing a thermal cutoff varistor of the present invention.

4A and 4B are circuit diagrams showing a current passing through a protection circuit or a thermal cutoff varistor.

5A and 5B are a plan view and a circuit diagram of another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

1: thermal cutoff varistor

2: protection circuit

10: base body

20 electrode

30: conductor

31: thermally soluble alloy

40: coating layer

32: tension spring

33: insulated tube

50: first conductor

60: second conductor

In Fig. 3, the thermal cutoff varistor 1 of the present invention has a base body 10, two electrodes 20 attached on the front side and the rear side of the base body 10, and the electrode 20. And a coating layer 40 coated on the base body 10, the electrode 20, and the conductor 30. A predetermined region of the conductor 30 is connected to the thermally soluble alloy 31 and the tension spring 32, which are installed in the insulating tube 33. The thermal cutoff varistor 1 is connected in parallel with the protection circuit 2 to form a line up to the line protection connection.

When the voltage is in a steady state, the current flows into the protection circuit 2, wherein the thermal cutoff varistor 1 is an open circuit as shown in Fig. 4A. On the other hand, the resistance value of the thermal cutoff varistor 1 preferentially decreases until the voltage becomes steady when an overvoltage is generated so that current flows into the thermal cutoff varistor 1, wherein the thermal cutoff is shown in Fig. 4B. As if it were a closed circuit.

However, an overcurrent or surge current flowing into the thermal cutoff varistor 1 generates a high temperature on the thermal cutoff varistor 1, and the thermally soluble alloy 31 prevents the varistor itself and the downstream electrical appliance from being burned out or exploded. Can be melted to break to cut off the current of the power source, and the tension spring 32 can pull the thermally soluble alloy 31 to break immediately when the thermally soluble alloy 31 is melted by overcurrent or surge current.

5A and 5B are a plan view and a circuit diagram showing another embodiment of the present invention, and as shown in FIG. 5A, the thermal cutoff varistor 1 includes a base body 10 and two of the base body 10. Forming a common line with two electrodes 20 attached on the side, and a conductor 10 and a first conductor 50 connected to one of the electrodes 20 to form an AC input line and an AC output line, respectively And a second conductor 60 connected to the other electrode 20. Thus, as shown in FIG. 5B, the conductor 30, the thermal cutoff varistor 1, the second conductor 50, and the protection circuit 2 form a series circuit, and the conductor 30, the thermal cutoff varistor 1. The second conductor 60 and the protection circuit 2 form a parallel circuit. When the voltage is steady, current passes through the conductor 30, the thermal cutoff varistor 1, the first conductor 50, and the protection circuit 2, where the thermal cutoff varistor 1 can be used as a fuse. On the other hand, the resistance value of the thermal cutoff varistor 1 decreases until the voltage becomes a normal state when the overvoltage occurs such that the overcurrent passes through the conductor 30, the thermal cutoff varistor 1 and the second conductor 60. do.

Accordingly, the thermal cutoff varistor has the following advantages and characteristics.

(1) Thermal cutoff varistors are broken by thermally soluble alloys that are melted and pulled by tension springs to prevent the varistor itself and downstream electrical appliances from being exhausted or exploded when an overcurrent or surge current passes through them. Can be cut off.

(2) Thermally soluble alloys and tension springs are installed in the insulation tube to prevent moisture and dust that affect the function of the thermally soluble alloys and tension springs.

It will be appreciated by those skilled in the art that the above description is a preferred embodiment of the disclosed apparatus and that various changes are possible within the spirit of the present invention.

The present invention can automatically cut off the current of the power supply by thermal cutoff control to protect the varistor itself and downstream electrical appliances when an overcurrent or surge current passes through the varistor, and the varistor is connected to the power supply when an overcurrent or surge current occurs. It is possible to provide a varistor that can be connected in series and parallel to the protection circuit so as to absorb overvoltage or to cut off the current.

Claims (3)

In the thermal cutoff varistor, With the base body, Two electrodes attached on two sides of the base body, A conductor connected to one of the electrodes, A coating layer coated on the base body, the two electrodes and the conductor; A thermally soluble alloy and a tension spring connected to a predetermined area of the conductor and installed inside the insulation tube, The thermal cutoff varistor is connected in parallel with the protection circuit, the current flows into the protection circuit when the voltage is steady, and the resistance value of the thermal cutoff varistor decreases when an overvoltage occurs and this current flows into the thermal cutoff varistor. And the thermally soluble alloy can be melted to break to cut off the current of the power supply to prevent the varistor and downstream electrical appliance from being exhausted or exploded when an overcurrent or surge current passes through the varistor. . The thermal cutoff varistor of claim 1, wherein the tension spring is capable of pulling the thermally soluble alloy to break immediately when the thermally soluble alloy melts by overcurrent or surge current. 3. The thermal cutoff varistor of claim 1 or 2, wherein the thermal cutoff varistor comprises a base body, two electrodes attached on two sides of the base, a conductor connected to one of the electrodes, respectively, to form an AC input and an AC output. By including one conductor, a second conductor connected to the other electrode to form a common line, the varistor is in series or parallel so that the overcurrent or surge current can absorb the overvoltage or cut off the current of the power supply as it passes through the varistor. A thermal cutoff varistor, characterized in that it can be connected to a protective circuit in a connected manner.