JPH0113362Y2

JPH0113362Y2 -

Info

Publication number: JPH0113362Y2
Application number: JP567183U
Authority: JP
Priority date: 1983-01-19
Filing date: 1983-01-19
Publication date: 1989-04-19
Also published as: JPS59112903U

Description

【考案の詳細な説明】産業上の利用分野本考案は、音響機器に関連する小型直流モータ
のノイズ防止、リレー接点の保護、半導体素子の
静電気に対する保護等に使用されるバリスタに関
する。[Detailed Description of the Invention] Industrial Application Field The present invention relates to a varistor used for noise prevention of small DC motors related to audio equipment, protection of relay contacts, protection of semiconductor elements against static electricity, and the like.

従来技術従来のこの種のバリスタは、一般に、円環状等
の適当な形状に形成されたバリスタ素体の表面も
しくは裏面または両面に、一個またはそれ以上の
個数の電極を被着形成した構造となつている。第
１図及び第２図は従来のバリスタの一例を示し、
円環状に形成されたバリスタ素体１の表面に、ギ
ヤツプＧによつて分割された複数の分割電極２，
３及び４を設け、裏面に前記電極２〜４に共通に
対向する共通電極５を設けた構造となつている。
前記バリスタ素体１としては、シリコンカーバイ
ト（SiC）系、酸化錫（Sn02）系、酸化鉄
（Fe203）系、酸化チタン（Ti02）系またはチタ
ン酸ストロンチウム（SrTi0₃）系等の焼結体が
使用される。Conventional varistors of this type generally have a structure in which one or more electrodes are adhered to the front or back surface or both surfaces of a varistor element body formed in an appropriate shape such as an annular shape. ing. 1 and 2 show an example of a conventional varistor,
A plurality of divided electrodes 2 divided by gaps G are provided on the surface of the varistor body 1 formed in an annular shape.
3 and 4 are provided, and a common electrode 5 is provided on the back surface to commonly face the electrodes 2 to 4.
The varistor element 1 is a sintered body of silicon carbide (SiC), tin oxide (Sn02), iron oxide (Fe203), titanium oxide (Ti02), or strontium titanate (SrTi0 ₃ ). is used.

第３図は第１図及び第２図に示した従来のバリ
スタの電気的等価回路図であり、分割電極２，３
及び４の各々と共通電極５との間に、バリスタ特
性Vz２，Vz３，Vz４と並列に、静電容量Ｃ２
５，Ｃ３５，Ｃ４５を接続した回路構成となる。 FIG. 3 is an electrical equivalent circuit diagram of the conventional varistor shown in FIGS. 1 and 2.
and 4 and the common electrode 5, a capacitance C2 is connected in parallel with the varistor characteristics Vz2, Vz3, Vz4.
The circuit configuration is that 5, C35, and C45 are connected.

上記の等価回路において、スパイク状の火花雑
音やリード伝播ノイズ等がバリスタ電圧を越えた
場合はそのバリスタ特性により電圧をカツトし、
一方、印加電圧がバリスタ電圧より低い電圧範囲
では一種のコンデンサとして動作し、電極間に発
生する静電容量Ｃ２５，Ｃ３５，Ｃ４５によりノ
イズを消去する。 In the above equivalent circuit, if spike-like spark noise or lead propagation noise exceeds the varistor voltage, the voltage is cut off by the varistor characteristics.
On the other hand, in a voltage range where the applied voltage is lower than the varistor voltage, it operates as a kind of capacitor, and noise is eliminated by the electrostatic capacitances C25, C35, and C45 generated between the electrodes.

従来技術の欠点ところで、当該バリスタを、例えばエレクトロ
ガバナ付モータ回路のノイズ消去用として使用し
た場合、バリスタの持つ静電容量値Ｃ２５，Ｃ３
５，Ｃ４５とエレクトロガバナ回路の定数値との
インピーダンスマツチングが悪いと、逆に発振を
起しノイズ消去ができなくなるので、バリスタの
持つ静電容量Ｃ２５，Ｃ３５，Ｃ４５の値を、イ
ンピーダンスマツチングを取るのに適当に値に調
整することが必要になる場合がある。静電容量Ｃ
２５，Ｃ３５，Ｃ４５は、バリスタ素体の焼成法
や材料選択によつて変更することが可能である
が、電極の重なり面積を変更する方法が最も簡単
で確実である。ところが、従来のバリスタは、前
述した如く、分割電極２〜４と共通電極５とを、
互いに重なり合わせて対向させてあつたため、分
割電極２〜４と共通電極５との重なり面積を調整
して静電容量Ｃ２５，Ｃ３５，Ｃ４５を調整しよ
うとすると、バリスタ電圧が、静電容量の変化に
対して逆相関の関係で、大きくが変化してしま
う。このため、従来のバリスタにおいては、電極
面積の調整による静電容量値のコントロールが非
常に因難であつた。Disadvantages of the Prior Art By the way, when the varistor is used, for example, for noise cancellation in a motor circuit with an electrogoverner, the capacitance values C25 and C3 of the varistor are
5. If the impedance matching between C45 and the constant value of the electro-governor circuit is poor, oscillation will occur and noise cancellation will not be possible. It may be necessary to adjust the value appropriately to obtain . Capacitance C
25, C35, and C45 can be changed by the firing method and material selection of the varistor body, but the easiest and most reliable method is to change the overlapping area of the electrodes. However, in the conventional varistor, as mentioned above, the divided electrodes 2 to 4 and the common electrode 5 are
Since they overlapped and faced each other, when trying to adjust the capacitances C25, C35, and C45 by adjusting the overlapping area of the divided electrodes 2 to 4 and the common electrode 5, the varistor voltage changes due to the change in capacitance. There is an inverse correlation between the two, and the amount changes greatly. For this reason, in conventional varistors, it has been extremely difficult to control the capacitance value by adjusting the electrode area.

本考案の目的そこで本考案は、上述する従来からの問題点を
解決し、バリスタ電圧の変化を抑えつつ、静電容
量を所望の値に容易に調整し得るようにしたバリ
スタを提供することを目的とする。Purpose of the present invention Therefore, the present invention aims to solve the above-mentioned conventional problems and provide a varistor that can easily adjust the capacitance to a desired value while suppressing changes in the varistor voltage. purpose.

本考案の構成上記目的を達成するため、本考案は、相対する
両面にそれぞれ電極を設けたバリスタにおいて、
前記両面の電極は、互いに重なり合わない位置に
形成したことを特徴とする。Structure of the present invention In order to achieve the above object, the present invention provides a varistor in which electrodes are provided on each opposing surface.
The electrodes on both surfaces are characterized in that they are formed at positions that do not overlap with each other.

実施例第４図は本考案に係るバリスタの正面図、第５
図は第４図のＡ−Ａ線上における断面図、第６図
は同じくその背面図である。図において、第１図
及び第２図と同一の参照符号は同一性ある構成部
分を示している。この実施例では、酸化チタン
（Ti02）系またはチタン酸ストロンチウム
（SrTi0₃）系等のバリスタ素体１の表面側の外周
寄りに、ギヤツプＧによつて複数に分割された電
極２〜４を形成すると共に、裏面側の中心寄りの
前記分割電極２〜４と重なり合わない位置に、円
環状の共通電極５を形成した構造となつている。
即ち分割電極２〜４の内端縁半径をr1とし、共通
電極５の外端縁半径をr2としたとき、r1＞r2とな
るようにし、分割電極２〜４の内端縁と共通電極
５の外端縁との間に、前記半径差（r1−r2）だけ
のギヤツプｇが生じるように形成するのである。
このような構造であると、前記ギヤツプｇの幅を
増減調整することにより、分割電極２〜４と共通
電極５との間に発生する静電容量Ｃ２５，Ｃ３
５，Ｃ４５を減少させまたは増加させることがで
きる。しかも、この場合、電極面積の増減が非常
に小さくて済むから、バリスタ電圧の変化を従来
より著しく小さくすることができる。このため、
静電容量の調整、特に10μF前後の低静電容量領
域の調整及び素子製造が非常に容易になり、例え
ばエレクトロガバナ付マイクロモータに対するイ
ンピーダンスマツチグ等が非常に取り易くなる。
なお、実施例では酸化チタン系にバリスタを示し
たが、Zn0系等の他のバリスタであつてもよい。
また分割電極２〜４を共通電極５より内径側に形
成する等、他の態様を取ることも可能である。Example Figure 4 is a front view of the varistor according to the present invention, Figure 5 is a front view of the varistor according to the present invention.
The figure is a sectional view taken along line A--A in FIG. 4, and FIG. 6 is a rear view thereof. In the figures, the same reference numerals as in FIGS. 1 and 2 indicate the same components. In this embodiment, electrodes 2 to 4 divided into a plurality of parts by a gap G are formed near the outer periphery on the surface side of a varistor element body 1 made of titanium oxide (Ti02) or strontium titanate ( _SrTi03 ). At the same time, it has a structure in which an annular common electrode 5 is formed near the center of the back side at a position that does not overlap with the divided electrodes 2 to 4.
That is, when the radius of the inner edge of the divided electrodes 2 to 4 is r1, and the radius of the outer edge of the common electrode 5 is r2, the relationship between the inner edge of the divided electrodes 2 to 4 and the common electrode 5 is such that r1>r2. A gap g corresponding to the radius difference (r1-r2) is formed between the outer edge of the outer edge and the outer edge of the outer edge.
With such a structure, by increasing or decreasing the width of the gap g, the capacitances C25 and C3 generated between the divided electrodes 2 to 4 and the common electrode 5 can be reduced.
5, C45 can be decreased or increased. Moreover, in this case, the change in electrode area is very small, so the change in varistor voltage can be made much smaller than in the past. For this reason,
Adjustment of capacitance, especially in the low capacitance region of around 10 μF, and device manufacturing become very easy, and impedance matching for, for example, a micromotor with an electro-governor becomes very easy.
In addition, although titanium oxide-based varistors are shown in the examples, other varistors such as Zn0-based varistors may be used.
It is also possible to adopt other configurations, such as forming the divided electrodes 2 to 4 on the inner diameter side of the common electrode 5.

本考案の効果以上述べたように、本考案は、相当する両面に
それぞれ電極を設けたバリスタにおいて、前記両
面の電極は、互いに重なり合わない位置に形成し
たことを特徴とするから、バリスタ電圧の変化を
抑えつつ、静電容量を所望の値に容易に調整し得
るようにしたバリスタを提供することができる。Effects of the present invention As described above, the present invention is characterized in that in a varistor in which corresponding electrodes are provided on both sides, the electrodes on both sides are formed at positions that do not overlap with each other, so that the varistor voltage can be reduced. It is possible to provide a varistor whose capacitance can be easily adjusted to a desired value while suppressing changes.

[Brief explanation of the drawing]

第１図は従来のバリスタの正面図、第２図は同
じくその側面断面図、第３図は同じくその電気的
等価回路図、第４図は本考案に係るバリスタの正
面図、第５図は第４図のＡ−Ａ線上における断面
図、第６図は同じく背面図である。１……バリスタ素体、２〜５……電極、ｇ……
ギヤツプ。 FIG. 1 is a front view of a conventional varistor, FIG. 2 is a side sectional view thereof, FIG. 3 is an electrical equivalent circuit diagram thereof, FIG. 4 is a front view of a varistor according to the present invention, and FIG. FIG. 4 is a sectional view taken along line A-A, and FIG. 6 is a rear view. 1... Varistor element body, 2-5... Electrode, g...
Gap.

Claims

[Claims for Utility Model Registration] (1) A varistor in which electrodes are provided on opposing surfaces, characterized in that the electrodes on both surfaces are formed at positions that do not overlap with each other. (2) The varistor according to claim 1, wherein the electrodes on both sides are formed in the shape of a cylindrical ring. (3) The varistor according to claim 1 or 2, wherein one of the electrodes formed on both surfaces is a plurality of divided electrodes. (4) The varistor according to claim 3, wherein the other of the electrodes formed on both surfaces is a common electrode common to the divided electrodes. (5) The varistor according to claim 1, 2, 3, or 4, wherein the varistor body is made of titanium oxide or strontium titanate.