The Common Mode Choke – Uses and Types

by | Jul 12, 2016 | Electronics & Electricals

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The common mode choke is used in various industries including electronic and telecommunications. Understanding what the choke is, how it is used, and the different types available can be a big help in placing an order with engineering and manufacturing companies.

What is a Common Mode Choke?
A common mode choke is a part generally used in the electrical industry. It is often referred to as a common mode inductor. It is where both the line and neutral windings are wound on a single core.

They are applied in order to supply and return pairs of conductors. They are most ideal for EMI (electromagnetic interference) filtering of signal and power lines as they are able to withstand high DC currents without inhibiting performance degradation.

How is the Common Mode Choke Used?
Generally, a common mode choke is used to filter common mode EMI currents without de-rating under high currents or causing single degradation.

These parts are most often used in a variety of industries. For example, the choke may be used in automotive applications, suppression or radiation noise in electronics, countering common mode noise affecting signals in high-speed lines, USB line for PCs and other peripheral equipment, and even in panel link lines for LCD panels.

Types Available
Common mode chokes can be categorized in several different ways. For instance, they can be categorized or typed by case size, dimension, impedance, rated current, maximum DC resistance, packaging type and rated voltage.

When dealing with rated voltage, common sizes for chokes are 50V, 250V and 500V. Some can be designed with rated voltages as high as 250kV. Some chokes may have a current between .4mA and 23 A. However, they most often have a rated current of 500mA, 1A or 2A.

Purchasing Common Mode Chokes
If purchasing common mode chokes for electrical work, check with engineering and manufacturing companies that can provide a variety of options in as little turnaround time as possible. Companies that provide samples for customers to determine if it’s the item needed are especially helpful.

Also ask about product order limits or minimums. Again, companies that can work with custom orders or various sizes are a plus. Engineers that are available to help determine specific order needs are also preferable when ordering.

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