VTdrive What is a Choke Coil0 pages
A choke coil is a part used in electrical circuits to allow DC current to flow
through while blocking AC current from passing. These coils are used in a
number of electrical devices. When used as part of a radio’s circuitry, it falls into
one of two frequency classes: audio or radio. Those used in circuits with higher
frequencies use different core materials than those used in lower frequency
circuits.
During the process of sending a signal through a circuit, the idea is to let the
desired signal go through while filtering out other, unwanted signals. One type
of unwanted signal is common-mode noise, which is filtered out by a
common-mode choke coil. Power lines are an example of a source of
common-mode noise. Without a coil, the power line would create a lot of
electrical noise as it traveled to its destination, which would then be received on
the other end and possibly cause interference with the signal.
The choke coil works because it acts as an inductor. When the current passing
through changes, as AC currents do, it typically creates a magnetic field in the
coil that works against that current. This property, known as inductance, blocks
most of the AC current from passing through. As a result, currents that do not
change, such as DC currents, can continue through while those that do are
blocked by the very magnetic field they created.
A choke coil is used as an inductor in an electrical circuit.
Power lines are a source of common-mode noise.
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