Choke Vs Filter

[czping]

Hi,

Just a bit confused over the use of "choke" and "filter"..
When is a "choke" (inductor) use? And when is a "filter (Capacitor & resistor) used? What I understand is that both are used for filtering purposes, pls correct me if I am wrong...

Thank u!!!

czping

 

[electricuwe]

From my point of view a filter is at least consisting of two components. For power applications usually an inductor/capacitor arrangement is preferred to a resistor/capacitor filter due to the following reasons:

lower heat loss
higher attentuation (2nd order vs. 1st order frequency response)

 

[jmarko]

Hi, czping!

I think that inductors are used to filter out (or to smooth) current surges, mostly caused by load. And capacitive filters are used to filter out voltage disturbances, caused by lightning or other loads on supply line, that are source of voltage spikes (tyristor/triac or relay switched loads, motors etc.) .

Best regards, Jmarko

 

[Alex68]

Hi czping,
thank you because you obliged me to study a new problem!

The CHOKE is a particular kind of filter used especially in dc circuit, for instance communication systems. It is a longitudinal coil, sometimes with a capacitor connected to ground. In normal operation the coil doesn't work in a dc circuit, but in case of an induced current the choke damps it.

A filter composed by a resistor and a capacitor is ususally utilised in electronic circuit because of its big heat loss. In ac power system the L-C filters are preferred. They are connected between phase and neutral and they are sized for a particular resonance frequency.

Ciao
Alex68

 

[kuwait]

friends,
THE RULE IS
CURRENT THRO AN INDUCTOR CANNOT CHANGE INSTANTANEOUSLY AND VOLTAGE ACROSS CAPACITOR CANNOT CHANGE INSTANTANEOUSLY.HENCE THEIR USAGE