JPH0124448B2 - - Google Patents
Info
- Publication number
- JPH0124448B2 JPH0124448B2 JP58047127A JP4712783A JPH0124448B2 JP H0124448 B2 JPH0124448 B2 JP H0124448B2 JP 58047127 A JP58047127 A JP 58047127A JP 4712783 A JP4712783 A JP 4712783A JP H0124448 B2 JPH0124448 B2 JP H0124448B2
- Authority
- JP
- Japan
- Prior art keywords
- noise
- capacitor
- coil
- resistor
- filter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000003990 capacitor Substances 0.000 claims description 19
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 3
- 230000002238 attenuated effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- 238000013016 damping Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/01—Frequency selective two-port networks
Landscapes
- Filters And Equalizers (AREA)
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明はコイルを並列接続した抵抗とコイルと
コンデンサとで構成することにより、パルス幅が
狭いがエネルギー密度の高いノイズをも除去でき
るノイズフイルタに関する。[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a noise filter that can remove noise with a narrow pulse width but high energy density by being configured with a resistor with a coil connected in parallel, a coil, and a capacitor. .
従来、ノイズフイルタはコイルとコンデンサに
より構成した低域通過型フイルタであるためパル
ス幅が狭いノイズが入るとコンデンサとコイルの
値により定まる共振周波数の減衰振動が出力に現
われるため、ノイズのエネルギー密度が大きい場
合には大きな電圧の減衰振動が出力に現われノイ
ズフイルタとしての機能が発揮できずに、ノイズ
フイルタを設置してある装置が誤動作するという
欠点があつた。
Traditionally, noise filters are low-pass filters composed of a coil and a capacitor, so when noise with a narrow pulse width enters, a damped oscillation with a resonant frequency determined by the values of the capacitor and coil appears in the output, which reduces the energy density of the noise. If the noise filter is large, a damped vibration of a large voltage appears in the output, and the function as a noise filter cannot be achieved, resulting in malfunction of the equipment equipped with the noise filter.
本発明の目的は、パルス幅が狭いがエネルギー
密度が高いノイズが入つても除去できるノイズフ
イルタを提供することにある。
SUMMARY OF THE INVENTION An object of the present invention is to provide a noise filter that can remove noise having a narrow pulse width but high energy density.
本発明の第１の原理は、パルス幅が狭いノイズ
を抵抗とコンデンサの低域フイルタで除去し、装
置が必要なノイズのない電源あるいは信号はコイ
ルを通すことであり、第２の原理はフイルタを構
成するコンデンサのリード線等による残留インダ
クタンス成分によるノイズの漏れをコイルにより
防ぐことである。
The first principle of the present invention is to remove noise with a narrow pulse width using a low-pass filter of resistors and capacitors, and to pass the noise-free power supply or signal necessary for the device through the coil. The coil is used to prevent noise leakage due to residual inductance components from the lead wires of the capacitors that make up the circuit.
以下、本発明の第１の実施例を第１図により説
明する。第１図において、１は入力端子、２は出
力端子、３，４はコイル、５は抵抗、６はコンデ
ンサを示す。コイル３の値をL0、コイル４の値
をL1、抵抗５の値をＲ、コンデンサ６の値をＣ、
コンデンサ６のリード線等の残留インダクタンス
をLs、ノイズの最大のパルス幅をtw、ノイズ目標
抑制率をαとし、
RC＜tw／α、Ｌ／Ｒ＞10・tw ……(1)
LO／LS≫１ ……(2)
なる様に定数を選べば、twよりも狭いパルス幅の
ノイズが入つた時、ノイズによる電流の90％以上
が抵抗５を流れ、抵抗５とコンデンサ６から構成
される回路により減衰し、コイル４にはほとんど
ノイズ電流が流れないため減衰振動が発生しな
い。また、コイル３があることにより、コンデン
サ６に流れるノイズ電流の時間的な変化量が抑え
られているため、コンデンサ６のリード線等の残
留インダクタンスで起こる電圧降下を少くするこ
とができる。他方、パルス幅の大きい信号あるい
は直流は、コイル３、コイル４を減衰することな
く通過することができる。
A first embodiment of the present invention will be described below with reference to FIG. In FIG. 1, 1 is an input terminal, 2 is an output terminal, 3 and 4 are coils, 5 is a resistor, and 6 is a capacitor. The value of coil 3 is L 0 , the value of coil 4 is L 1 , the value of resistor 5 is R, the value of capacitor 6 is C,
Let L s be the residual inductance of the lead wire of the capacitor 6, tw be the maximum pulse width of the noise, α be the target noise suppression rate, and RC< tw /α, L/R>10・tw ...(1 ) L O /L S ≫ 1 ...(2) If the constants are chosen so that when noise with a pulse width narrower than t w enters, more than 90% of the current due to the noise will flow through resistor 5, and resistor 5 and a capacitor 6, and since almost no noise current flows through the coil 4, no damped vibration occurs. Further, since the presence of the coil 3 suppresses the amount of change over time in the noise current flowing through the capacitor 6, the voltage drop caused by the residual inductance of the lead wire of the capacitor 6, etc. can be reduced. On the other hand, a signal with a large pulse width or a direct current can pass through the coils 3 and 4 without being attenuated.
以上、述べた様に、本実施例によれば、パルス
幅の狭いノイズが入力されても出力には減衰振動
の少ない十分なノイズ減衰効果を得ることができ
る。 As described above, according to this embodiment, even if noise with a narrow pulse width is input, a sufficient noise damping effect with less damped vibration can be obtained in the output.
第２図に本発明の第２の実施例を示す。第２図
において、１は入力端子、２は出力端子、３，３
ａ，４，４ａはコイル、５，５ａは抵抗、６，６
ａはコンデンサを示す。本実施例は第１の実施例
を直列接続したものであり、抵抗５の値をＲ、抵
抗５ａの値をRa、コンデンサ６の値をＣ、コン
デンサ６ａの値をCaとした時
RC＜RaCa
とすることによりノイズの減衰が大きくとれるこ
とは明白である。また、コンデンサ６のリード線
等の残留インダクタンスによるノイズ電圧降下の
発生量が小さければ、コイル３ａをはぶいても良
い。 FIG. 2 shows a second embodiment of the invention. In Figure 2, 1 is an input terminal, 2 is an output terminal, 3, 3
a, 4, 4a are coils, 5, 5a are resistors, 6, 6
a indicates a capacitor. This embodiment is a series connection of the first embodiment, and when the value of the resistor 5 is R, the value of the resistor 5a is Ra, the value of the capacitor 6 is C, and the value of the capacitor 6a is Ca, RC<RaCa It is clear that noise can be greatly attenuated by doing so. Further, if the amount of noise voltage drop caused by the residual inductance of the lead wire of the capacitor 6 is small, the coil 3a may be removed.
なお、本実施例は第１の実施例のフイルタを２
つ直列接続したものであるが、３段以上の直列接
続であればそのノイズ抑制効果は増加することは
明白である。 Note that this embodiment uses two filters in the first embodiment.
However, it is clear that the noise suppression effect will increase if three or more stages are connected in series.
以上、本発明によれば、フイルタにパルス幅の
狭いノイズが入つても、出力に減衰振動をほとん
ど出さなく、装置に誤動作を与えることがなくな
る。
As described above, according to the present invention, even if noise with a narrow pulse width enters the filter, almost no damped oscillation is produced in the output, and the device is prevented from malfunctioning.
第１図は本発明の一実施例の回路図、第２図は
本発明の他の実施例の回路図である。
１……入力端子、２……出力端子、３，４，３
ａ，４ａ……コイル、５，５ａ……抵抗、６，６
ａ……コンデンサ。
FIG. 1 is a circuit diagram of one embodiment of the invention, and FIG. 2 is a circuit diagram of another embodiment of the invention. 1...Input terminal, 2...Output terminal, 3, 4, 3
a, 4a... Coil, 5, 5a... Resistor, 6, 6
a... Capacitor.
Claims (1)
てコンデンサのみを用い、コイル部として、第１
のコイルと第２のコイルとを直列に接続し、上記
第１または第２のコイルのいずれか一方に上記コ
ンデンサとで構成されるRCフイルタにより高い
周波数成分のノイズを阻止する抵抗を並列に接続
した回路を用いたことを特徴とするノイズフイル
タ。1. Use only a capacitor as the capacitor part of the low-pass L-type LC filter, and use the first as the coil part.
A coil and a second coil are connected in series, and a resistor is connected in parallel to either the first or second coil to block high frequency component noise using an RC filter consisting of the capacitor. A noise filter characterized by using a circuit made of
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4712783A JPS59172822A (en) | 1983-03-23 | 1983-03-23 | Noise filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4712783A JPS59172822A (en) | 1983-03-23 | 1983-03-23 | Noise filter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59172822A JPS59172822A (en) | 1984-09-29 |
| JPH0124448B2 true JPH0124448B2 (en) | 1989-05-11 |
Family
ID=12766473
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4712783A Granted JPS59172822A (en) | 1983-03-23 | 1983-03-23 | Noise filter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59172822A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05121988A (en) * | 1991-10-24 | 1993-05-18 | Matsushita Electric Ind Co Ltd | Low pass filter for power line carrier communication |
| JP2003198306A (en) | 2001-12-25 | 2003-07-11 | Emc Kk | Noise filter and electronic device therewith |
| JP3957206B2 (en) * | 2003-06-26 | 2007-08-15 | イーエムシー株式会社 | Noise filter for safety ground wire and electronic device equipped with the same |
| GB2457940B (en) * | 2008-02-29 | 2013-05-01 | Nujira Ltd | Improved filter for switched mode power supply |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS504100A (en) * | 1973-05-16 | 1975-01-16 | ||
| JPS5722447A (en) * | 1980-07-14 | 1982-02-05 | Mazda Motor Corp | Change position displaying apparatus |
-
1983
- 1983-03-23 JP JP4712783A patent/JPS59172822A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS504100A (en) * | 1973-05-16 | 1975-01-16 | ||
| JPS5722447A (en) * | 1980-07-14 | 1982-02-05 | Mazda Motor Corp | Change position displaying apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59172822A (en) | 1984-09-29 |
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