JPS5838563Y2 - nonlinear resistor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a nonlinear resistor VC, and particularly to a nonlinear resistor used in an overvoltage protection device in an electrical system.

In electrical systems, overvoltage protection devices are used to remove overvoltages superimposed on normal voltages and protect electrical systems and electronic equipment.

This overvoltage protection device uses a non-linear resistor that exhibits substantially insulating properties at normal voltage and exhibits a relatively low resistance value when overvoltage is applied.

-fl of the overvoltage protection device is shown in FIG.

FIG. 1 shows what is generally called a lightning arrester 1, in which a non-linear resistor 3 and a discharge gap device 4 are connected in series and housed in an insulator tube 2.

The voltage rating of the non-linear resistor 3 is, for example, 400V, and when the voltage at which the overvoltage protection device is used is 1000V,
Used by connecting three in series.

The structure of the non-linear resistor 3 is shown in FIG.

In FIG. 2, a non-linear resistor 3 is constructed by providing, for example, an aluminum electrode 5 on both sides of a disc-shaped material 40 having non-linear resistance characteristics, and an insulating collar 6 on the side surface.

A lightning arrester 1 is constructed by connecting a plurality of such non-linear resistors 3, but if the voltage significantly exceeds the rated voltage of the lightning arrester, for example, there is a lightning strike, a flashover phenomenon occurs around the non-linear resistor, and the lightning arrester This had the disadvantage that the function as an object was impaired.

To address this drawback, for example, it is possible to improve the withstand voltage characteristics by increasing the number of non-linear resistors 3 used in the lightning arrester 1 in series, or by increasing the shape of the non-linear resistors 3. However, there was a need for a nonlinear resistor that could improve the withstand voltage characteristics at low cost.

The present invention was developed in view of the above-mentioned demands, and aims to provide a nonlinear resistor with good withstanding voltage characteristics.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 3, for example, silicon carbide (SIC) powder is mixed with an organic binder such as polyvinyl alcohol in a weight ratio of 50:1.
The mixture was mixed in the following proportions and formed into a disk with a diameter of 70 mm and a thickness of 121 g using a press.

This molded body is fired at a temperature of, for example, 1100° C. to produce a material 11 for the nonlinear resistor.

An insulating collar 12 having a thickness of, for example, about 0.2 is provided on the side surface of this material 11.

For example, aluminum is formed on both sides of the material 110 by a metal spraying method, electrodes 13 are provided, and the nonlinear resistor 14 is manufactured.

When forming the electrode 13 by metal spraying, the material 110
If a metal mask (not shown) is placed on the surface, material 1
A non-electrode portion 16 can be formed between the end portion 15 of the electrode 1 and the electrode 13.

For example, three non-linear resistors 14 are stacked one on top of the other, and when 10 KV is applied to the electrodes at both ends, the flashover start time is measured, and the results are shown in FIG. 4, using the length of the non-electrode portion 16 as a parameter.

As shown in FIG. 4, the shorter the length of the non-electrode portion 16, the more
It was confirmed that the flashover start time of the non-linear resistor was increased, and when used in an overvoltage protection device, the resistance to overvoltage was improved.

In particular, it has been confirmed that a non-linear resistor whose non-electrode portion has a length shorter than 1.5+u+ is sufficiently usable when used in an overvoltage protection device.

However, it is of course difficult in manufacturing to make the length of the non-electrode part shorter than Q, l1m, but if the length of the non-electrode part is less than 0.1111111, the current will flow between the electrodes at both ends through the end. Increased risk of passing.

Products with extremely short flashover start times are sometimes manufactured, resulting in large variations in characteristics and making it impossible to achieve the intended purpose.

Therefore, the length of the non-electrode portion with the most appropriate electrical I characteristic is 0. It is preferable to set it within a range of 111 to less than 1.5 m1.

In the above embodiment, the electrodes were made of aluminum by metal spraying, but instead of aluminum, copper was used.

Even if the electrode is made of brass, silver, tin, zinc, or an alloy thereof, the effect of the present invention can be obtained.

Furthermore, even if the shape and dimensions of the non-linear resistor are different from those in the above embodiment, the length of the non-electrode portion is set within the range of 0.1 to less than 1.5111, as is clear from FIG. Of course, if this is the case, the effects of the present invention can be obtained.

Next, another embodiment of the present invention will be described.

Mainly made of zinc oxide (Zno) as a non-linear resistor,
It is also known that metal oxide-added mixtures are molded, fired, and electroded for use in overvoltage protection devices.

For example, Zno86 mole, magnesium oxide (MgO)
More than 8 mol, bismuth oxide (Bi203) 2 mol%, antimony oxide (Sb203) 1.5 mol φ, cobalt oxide (CoC) 1.1 mol%, lithium oxide (Cr20:4)
0.5 mol%, manganese oxide (MnO) 0.5 mol%,
Iron oxide (F e 203 ) is mixed at a ratio of 0.4 mol%.

This mixture is calcined at a temperature of, for example, soo'c'. The calcined mixture is pulverized and mixed with, for example, polyvinyl alcohol.

Press the mixture to, for example, a diameter of 80 mm and a thickness of 181 nM.
Form into a disc.

This molded product is fired at a temperature of, for example, 1300° C. to produce a material for a nonlinear resistor.

An insulating collar is formed on the side surface of this material, and electrodes are formed by metal spraying, for example aluminum, on both halves to form a non-linear resistor.

The flashover start time was measured when, for example, three of these nonlinear resistors were stacked and 18 KV was applied to both terminal electrodes.

This is shown in FIG. 5 using the length of the non-electrode portion as a parameter.

In this example as well, the shorter the length of the non-electrode part of the non-linear resistor, the longer the flashover start time becomes, making it suitable for an overvoltage protection device. Confirmed that it can be used.

Of course, even in this embodiment, the effects of this article can be obtained even if the electrode material and electrode formation method are changed.

Furthermore, even if the composition, shape, dimensions, and manufacturing method of the material of the nonlinear resistor of this example are different, as long as it exhibits nonlinear resistance characteristics, the length of the non-electrode portion should be Q, li+m or 1. Of course, the effect of the present invention can be obtained by setting it to less than .5+u.

[Brief explanation of drawings]

Figure 1 is a partially cutaway side view showing -flJ of an overvoltage protection device that can use the non-linear resistor of the present invention, Figure 2 is a sectional view of a conventional non-linear resistor, and Figure 3 is the non-linear resistor of the present invention. A perspective view illustrating one embodiment of the resistor, and FIGS. 4 and 5 are curve diagrams illustrating the effects of the present invention. 11... Material of non-linear resistor, 13...
- Electrode, 16... Non-electrode part.

Claims (2)

[Scope of utility model registration request] (1) A nonlinear resistor exhibiting nonlinear resistance characteristics and comprising a plate-shaped material having two parallel opposing planes and an electrode formed on the 2,000 surfaces of the material, wherein the electrode is formed on the material. A non-linear resistor, characterized in that the non-linear resistor is formed within a range Q of 1 mm to less than 1.5 n from the end of the element. (2) Utility model registration claim No. 1, characterized in that the composition of the material exhibiting non-linear resistance characteristics is a mixture containing zinc oxide as a main ingredient and at least one type of metal oxide added.
The nonlinear resistor described in item 1).