What is Choke Coil? Types, Application, Properties, Diagram
In both electrical and electronics engineering, the term 'Choke Coil' is very well known to us. But, have you know, exactly what is a choke coil? or what is the exact function of a choke coil? In this article, we are going to know all about a choke coil including its types, properties, applications, and uses.
What is a Choke Coil?
A choke coil is nothing but an inductive coil whose main function is to block the high-frequency signals or current and allow the low-frequency alternating or DC current. The name or term 'choke' comes from the term 'Choking' whose other meaning is blocking. Generally, the choke coil is made up of a coil of insulated wire and the coil is wound on a magnetic core made of ferromagnetic material. The number of turns of the choke coil is very important. For high voltage blocking purposes, maximum turns are required. Basically, the choke coil is a non-polarized device we can connect in any polarity. Generally, it is connected in series with the power supply and load.
Choke Coil Diagram and Different Parts
Here, you can see a simple diagram of a choke coil and its different parts. As I told you before it has main two parts - coil and core. Sometimes it uses an enclosed cover also in which the choke coil is placed.
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Properties of a Choke Coil
1. The internal resistance of the choke coil is very low. This means it is built with a very high conductive wire.
2. The inductive reactance of the choke coil varies with the varying of frequency of the flowing current through it.
3. When the frequency is increasing, the inductive reactance also increases, and when the frequency decreases the inductive reactance also decreases.
4. As the inductive reactance varies with the varying of frequency, so impedance provided by a choke coil to the flow of alternating current also varies with the frequency.
5. The main function or property of a choke coil is to allow the Direct current or low-frequency Alternating Current and to block the high-frequency Alternating Current.
6. A Choke coil opposes the flow of electric current by its reactance property, not resistance property. So there is an advantage in that it does cause any power loss.
7. As the choke coil is basically an inductor or inductive coil, so it can store the electric energy in the form of a magnetic field.
8. A continuously varying current-carrying choke coil can produce Electromagnetic Interference(EMI). And this produced electromagnetic interference can affect nearby devices.
Types of Choke Coil
Choke coils are classified according to design, voltage rating, inductance ratings, application areas, etc. The different types of choke coils are,
- Common Mode Choke Coil
- Audio Frequency Choke Coil
- Radio Frequency Choke Coil
What is a Common Mode Choke Coil?
A common-mode choke coil is one that allows the differential current with an equal quantity flowing in opposite directions and also it blocks the common-mode current. A common mode choke coil is designed in such a way that two coils are wound on a single core with the opposite direction of the rotation. Here you can see the diagram of a common mode choke. The common mode choke coil is built with two individual magnetic coils.
What is an Audio Frequency Choke Coil?
Audio Frequency Choke Coil are those blocks the normal power line frequencies and audio frequency signals but they allow to passing of the DC current. Generally, the audio frequency choke coils are designed with a coil wound on a ferromagnetic core. This helps to increase its inductive property. This type of choke coil is smaller in size than others.
What is a Radio Frequency Choke Coil?
Radio Frequency Choke coils are those block the radio frequency signals and allow the other signals such as audio frequency signals, normal power frequency signals, and DC signals. Radio Frequency Choke coils are made up of a coil wound on a core of iron powder or ferrite materials. Generally, radio frequency choke coils are designed for ultra-high frequency applications.
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Choke Coil Applications and Uses
1. Choke coils are used in electronic circuits to reduce Electromagnetic Interference. You can see them in charger circuits, SMPS circuits, etc.
2. A choke coil is used with fluorescent tube light to produce a high voltage at the starting time.
3. Choke coils are used with sensitive cables and connectors such as USB Data cables, HDMI cables, etc to reduce noise and interferences.
4. Audio frequency choke coils are used in audio systems, subwoofers, etc.
5. Choke coils are also used in power supply circuits such as voltage regulators, rectifier circuits, inverter circuits, etc.
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What is Choke Coil? Types, Application, Properties, Diagram
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August 26, 2021
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