What is a noise filter and how is it used?

i think that filter the power 60Hz influence or EMI.

noise filter is used to filter high frequency noise on

signal line or power line.

best regards

Any unwanted signal is considered a noise, regardless noise appears in power rails or picked up in signal lines.

So long you want a filter to remove noise, it is called a noise filter.

ok...thanks...

then...could anyone tell me the types of the noise filter...any related info etc...tq :)

You Have not specified requirements for your "noise filter". Answer can be only general. Filter can be any of standard filter types, low pass, highpass, bandpass or band reject. There is no rule what type "noise filter" should be.

Borber,

Agreed. fhl didn't specify what he wants.


fhl,

You need to tell us about the noise charactheristics before anyone can offer you advice.

Such characteristics are:
1. The frequency at which the noise is present.
2. The power (in dB) about the noise.
3. Source of noise

Some books about the filter design introduce more informations about the spec.and type abput LP,HP,BP and stop pass.Also you can use some simulator to
get the result directly.