Ineroduction 濾波器基礎知識

--Our EMI filter are designed on the basis of IEC939-1、IEC939-2、EN13300、EN133200 and UL1283、

GB/T15287-1994、GB/T15288-1994 Standards. Our filter are the low-pass filter composed by the passive components

(L、C、R)and adopt the impedance  mismatch theory between filter and access port.

本公司產品符合IEC939-1、IEC939-2、EN13300、EN133200以及UL1283、GB/T15287-1994、GB/T15288-1994標準.

本手冊涉及的電源濾波器由無源元件（L、C、R）組成低通濾波器，含有共模和差模衰減網絡；采用了濾波器與接入

端的阻抗失配原理.濾波范圍在10KHz~30MHz，能有效抑制沿電源線傳導的EMI干擾。

General circuit configuration 阻抗搭配

Customers choose their own devices in the power filter, the device should be based on their actual

interference situation combined with power filter works to choose. Mains filter works by using an impedance mismatchat

both ends of the principle to work, so customers in the choice of power supply filter should refer to the principles

ofthe Fig.1, the only way to maximize the power supply filter filtering effect, to meet your requirements.

客戶在選擇適合自己設備使用的電源濾波器時，應該根據自己設備的實際干擾狀況結合電源濾波器的工作原理進行選擇.

電源濾波器的工作原理是利用兩端的阻抗失配原理進行工作的，所以客戶在選擇電源濾波器時應參照圖1所列的原則進行，只有這樣才能最大限度的發(fā)揮電源濾波器的濾波效果，以達到滿足您的要求。

Fig.1

Fig.2

* △FILTER: 3 phase power system without a Neutral phase is*  Y FILTER: 3 phase power system have a Neutral line called Y filter .

Leakage current: 泄露電流

Single-phase leakage-current measurement circuits

--單相漏電流測試原理圖

Filter internded for connection to a 2 wire power supply

濾波器用于連接一個2線供電

Filter intended for connection to a 3 wire power supply，ground neutral

power supply 濾波器用于連接一個3線供電,中線接地電源

Three-phase leakage-current measurement circuit

--三相漏電流測試原理圖

INSERTION  LOSS(IL)插入損耗

The insertion loss is measured according to CISPR 17. In most cases, published insertion loss data assumes that

power line and load have the same impedance and all such data are in practice generated form 50Ω test system.The best way to verity actual effectiveness in noise suppression is to mount the filter in the equipment to test the conducted emission in a shield room.

插入損耗的測試方法在CISPR17中有詳細規(guī)定，產品樣本上提供的插入損耗曲線是在50Ω系統(tǒng)上測試得出，即假定電源和負載的輸入、輸出兩側都是50Ω。但是，選用濾波器的最佳方法是將它接入使用設備在屏蔽房中進行實際測試。

Insertion loss i composed of common mode and differential mode insertion loss, and the test measurement circuit:插入損耗由共模和差模插入損耗組成，測試原理圖如下：

Common mode 共模

Differention mode 差模