JPH0246676A - Surge absorption device - Google Patents

Abstract

PURPOSE:To obtain a high surge resisting quantity by connecting not less than two pieces of surge absorption means, wherein microgap type surge absorption elements and resistance are connected in series, electrically and in parallel. CONSTITUTION:Not less than two pieces of surge absorption means c1 to cn, wherein microgap type surge absorption elements a1 to an and resistance b1 to bn are in series connected, are connected electrically and in parallel. Accordingly, when surge voltage is impressed on a surge absorption device and a current flows through the surge absorption elements of one of these surge absorption means c1 to cn, the other surge absorption are made to operate with voltage generated by the resistance value of the resistance of the surge absorption means, wherein the current flows, so as to be able to surely divide the surge current to respective surge absorption means. Thereby, a surge resisting quantity can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a surge absorption device, and particularly to a surge absorption device having high surge resistance.

[Conventional technology] Conventionally, surge absorption elements that absorb surge voltage include
Voltage nonlinear resistors such as gap type surge absorbers or zinc oxide varistors are widely used. However, gap-type surge absorbers have large discharge delays and lack of stability in characteristics due to light-dark effects, and zinc oxide-based varistors have low insulation resistance, making it difficult to obtain sufficient surge voltage absorption effects. It has its drawbacks.

The present applicant previously filed a patent application for a micro-gap type surge absorbing element (Japanese Unexamined Patent Publication No. 128283/1983) in order to eliminate the defective characteristics of conventional surge absorbing elements.
゜Hereinafter referred to as "Prior Application I." ).

As shown in FIG. 2, the surge absorbing element of the prior application (2) has electrodes 16 with lead wires 15 attached to both ends of a ceramic base 11 on which a conductive film 13 having a ceramic insulating groove 12 is formed.
This is placed in an insulating exterior body 17, and both ends thereof are sealed by heat fusion or the like. 14 is a ceramic element, and 18 is a space.

The microgap type surge absorbing element as shown in FIG. 2 has excellent characteristics such as no discharge delay or difference in characteristics due to brightness and darkness, and high insulation resistance value.

By the way, if the surge current applied to the surge absorbing element is expected to exceed the surge withstand capacity of one surge absorbing element, the surge withstand capacity can be increased by electrically connecting multiple surge absorbing elements in parallel. The applicant first developed a plurality of micro-gap type surge absorbing elements as described above as a surge absorbing device with extremely high surge resistance that can quickly absorb high voltage surges. proposed a surge absorption device electrically connected in parallel (Japanese Patent Application Laid-Open No. 57-76777. Hereinafter referred to as "Prior Application II
), i.e., first-to-file! The surge absorbing device (2) obtains high surge resistance by electrically connecting a plurality of micro-gap type surge absorbing elements in parallel and shunting the surge current to each surge absorbing element.

[Problem to be solved by the invention] However, the first application! In the surge absorbing device (2), if there is even a slight difference in the surge response characteristics of the surge absorbing elements connected in parallel, the surge will concentrate only on the element with good surge response. For this reason, as the current flows unbalanced, a current that exceeds the limit flows only to the discharged surge absorbing element and this element is destroyed. Therefore, even if multiple surge absorbing elements are connected in parallel, the overall surge withstand There were cases where it was not possible to reach a state where the amount of

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and provide a surge absorbing device that can reliably shunt surge current and has a high surge withstand capacity.

[Means for Solving the Problems] The surge absorption device of the present invention includes one in which two or more surge absorption means each having a micro-gap type surge absorption element and a resistor connected in series are electrically connected in parallel. It is characterized by

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a circuit diagram showing a surge absorbing device according to an embodiment of the present invention.

As shown in the figure, the surge absorbing device of the present invention includes micro-gap type surge absorbing elements a++a2...an and resistors b+
, b2...bn are connected in series, respectively, and two or more (n in Figure 1) surge absorbing means C+, C2...+Qn are electrically connected in parallel. be.

The microgap type surge absorption element used in the present invention is
The discharge starting voltage is not particularly limited as long as it is higher than the maximum circuit voltage of the circuit used. For example, a microgap type surge absorbing element as shown in FIG. 2 described above can be used.

Further, the resistor used in the present invention may be any resistor as long as it has the necessary surge resistance, and is not particularly limited, but it is preferably sufficiently lower than the circuit impedance of the circuit to be protected. Usually, a value of about 1 to 100 Ω is suitable.

The method of assembling the surge absorbing device of the present invention using these surge absorbing elements and resistors is not particularly limited, but if the shape is to be stabilized, the entire body may be covered with an appropriate coating material. The covering material is preferably a case with good insulation, an insulating covering material, or a heat-shrinkable tube, but is not particularly limited to these.

Further, as a method for connecting each element, caulking, soldering, wiring with a board, etc. are suitable, but the method is not particularly limited to these as long as it has the required surge resistance.

In the present invention, two or more surge absorbing means formed by connecting a surge absorbing element and a resistor in series are connected in parallel, but there is no particular restriction on the number of surge absorbing means to be connected, depending on the usage. An appropriate number of them are connected depending on the degree of surge current to be applied.

[Function] In the surge absorbing device of the present invention, a surge voltage is applied to the surge absorbing device by connecting two or more surge absorbing means formed by connecting a microgap type surge absorbing element and a resistor in series in parallel. When a current flows through the surge absorbing element of one surge absorbing means, the voltage generated by the resistance value of the resistor of the surge absorbing means through which the current flows operates the other surge absorbing means, and the surge current is transferred to each surge absorbing means. It is possible to reliably separate the flow.

That is, when a surge voltage is applied to the surge absorption device as shown in FIG. A discharge occurs in the surge absorbing element, for example Al. At this time, between B+ and B+', there is a resistor b connected in series with this discharged surge absorbing element al.
A voltage is generated that is the product of the sum of the resistance values of 1 and the flowing current value, and this voltage is also applied between 82 and 82' and between -Bn and Bn, so that other surge absorption elements a2 and・
・Discharge can also be generated in an.

For example, in a surge absorbing device formed by connecting two surge absorbing means CI and C2 in parallel, when a surge is applied to the device, a discharge occurs in one of the surge absorbing elements a1, which has good discharge response. and B l −B
A voltage that is the product of the sum of the resistance values of the discharged surge absorbing element a and the resistor b+ and the flowing current value is generated between I', and this voltage is also applied between B2 and 82'. , discharge also occurs in the other surge absorbing element a2.

The resistance value of the micro-gap surge absorption element during discharge is very small compared to the resistance value of the connected resistor, and by making the resistance values of the two resistors b+ and b2 equal, the surge current after discharge can be absorbed. It is equally divided into means C++02.

This discharge mechanism is a similar surge absorbing means CI +02...
The same applies when three or more c are connected in parallel, and the surge current is absorbed by the surge absorbing means ellc2 connected in parallel.
...Evenly divided into Cn.

Therefore, by increasing the number of surge absorbing means connected in parallel, the surge resistance can be increased.

It is clear from the graph of FIG. 3 that the surge withstand capacity is increased by increasing the number of parallel surge absorbing means. In FIG. 3, the horizontal axis shows the number of parallel surge absorbing means, and the vertical axis shows the surge withstand capacity of the surge absorbing device. According to this, the surge withstand capacity A of the surge absorber of the present invention
increases in proportion to the number (n) of surge absorption means connected in parallel, and the surge resistance A1 when there is one surge absorption means is different from the surge resistance when n surge absorption means are provided. The following relationship holds true for An.

[Example] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Example 1 As shown in Fig. 4, a surge absorption device was assembled in which two surge absorption means C+ and C2 were connected in parallel, each having micro-gap surge absorption elements al and B2 and resistors , and b2 connected in series. Ta.

Lead wire 1 was used for connection, and connection was made by caulking 2.

Further, the entire device was covered with an insulating case 3.

In addition, the microgap type surge absorption element a used,
The discharge starting voltage of ,B2 is 300V, and the resistance, ,b
2 used a 3Ω wire-wound resistor. These resistors b+ and b2 are coated on the outside with cement material and have a capacity of 3W. The surge withstand capacity of each of the surge absorption means CI and C2 connected in series was 1500A.

When we measured the surge withstand capacity of this surge absorber, we found that it was 3.
000A, which is twice as much as one surge absorbing means.

Example 2 Fig. 5 (circuit diagram), Fig. 6 (plan view).However, case 3
The upper surface and the filler 5 are not shown. ), Figure 7 (Figure 6■
As shown in FIG. 8 (cross-sectional view taken along the line ■-■) and FIG.
2 * a 3 + a 4 + B5 and the resistance plate, b
2. b3. b4. A surge absorbing device was assembled in which five surge absorbing means CI + 02 O03, C4, and O5 were connected in parallel. In this embodiment, these are connected on a substrate 4 and the whole is housed in an insulating case 3. Further, the space inside the case 3 was filled with an insulating filler 5. The micro-gap type surge absorbing element al''-'a5 and the resistors b1 to b5 are connected using caulking 2, which is soldered 6 to the board 4.7
is an electrode.

In addition, the microgap type surge absorption element a used,
``-'The discharge starting voltage of a5 is 2400V, and the resistance b
1 to b8 used wire-wound resistances of 10Ω. This resistance b+
~b5 is covered with cement material on the outside and has a capacity of 5
It is W. Surge absorption means cI connecting these in series
The surge resistance of Nc5 was 1500A.

When we measured the surge resistance of this surge absorber, we found that it was 7.
The current was 500A, which was five times that of one surge absorbing means.

[Effects of the Invention] As detailed above, according to the surge absorption device of the present invention,
The current discharged by the surge voltage can be reliably shunted, thereby greatly increasing surge resistance. Moreover,
By selecting the number of parallel surge absorbing means, the required surge resistance can be set arbitrarily.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a surge absorbing device according to an embodiment of the present invention, Fig. 2 is a sectional view showing a surge absorbing element according to the prior application (■), and Fig. 3 is a surge withstand capacity and surge absorption of the surge absorbing device. A graph showing the relationship with the number of parallel means, FIG. 4 is a sectional view of the surge absorber manufactured in Example 1, FIG. 5 is a circuit diagram of the surge absorber manufactured in Example 2, and FIG. 6 is the same. A plan view, FIG. 7 is a cross-sectional view taken along the line ■--■ in FIG. 6, and FIG. 8 is a cross-sectional view taken along the line ■--■ in FIG. 7. a l * a 2 + an... micro gap type surge absorption element, b l, b 2 * b n ””resistance, Cj I
+ 02 + On... Surge absorption means, 1... Lead wire, 2... Caulking, 3... Insulating case, 4... Board, 5... Insulating filler,
6...Solder, 7...Electrode, 11...
- Ceramic base, 12... Ceramic insulating groove, 13... Conductive film, 14... Ceramic element, 15... Lead wire, 16... Electrode, 1 frame...
...Insulating exterior body, 18...Space.

Claims (1)

[Claims] (1) A surge absorption device comprising two or more surge absorption means each electrically connected in parallel, each consisting of a microgap surge absorption element and a resistor connected in series.