In electronics, ferrite cores are considered magnetic cores consisting of windings of transformers, and other wound components are formed, such as inductors. They are more commonly used because of their high magnetic permeability and low electric conductivity. Because they result in low losses even at high frequencies. They are used in the cores or radiofrequency transformers and inductors for applications like loopstick antennas for AM radio receivers and switched-mode power supplies.
What are Ferrite Cores?
There are two types of noises classified in the transmission system. One is common-mode noise, and the other is differential mode noise. The common-mode noise or signal is unwanted because it does not carry any information; this is where the ferrite cores come into play. They are mainly used to eliminate the common-mode noise generated from either a power cable or a signal line.
How Do Ferrite Cores Work?
As already mentioned, the primary purpose of a ferrite core is to get rid of the unwanted signal or noise known as the common mode noise because it does not carry any useful information. These cores achieve this by suppressing the electromagnetic emissions by blocking the low-frequency signal and absorbing the high-frequency one. As a result of this, electromagnetic interference can be avoided.
How to Choose the Right Ferrite Core?
To choose the proper ferrite core, you must first identify the problem frequency and check the available space. The next step will be to select a suitable ferrite core. Choose a ferrite core with as high impedance as possible to cover up the problem frequency. You can choose the unified ferrite core by referring to the ferrite core's ID, OD, and length.
Application Areas of Ferrite Cores
In broad terms, two applications of ferrite cores have been identified, which also differ according to the size and frequency requirement of the operation. The first one is signal transformers that are small and have higher frequencies. The other one is power transformers that are large-sized and have lower frequencies. You can also classify ferrite cores based on their shapes like toroidal cores, cylindrical cores, or shell cores.
The ferrite cores used for the power transformers are large and carry low frequencies, and they can be either shell-shaped, toroidal, or shaped like the letter C, D, or E. They are effectively used in all sorts of electronic switching devices. Significantly, the power supplies range from 1 Watt to 1000 Watts since the more string applications are not within the range of the ferritic single-core and need the grain-oriented laminated cores.
The ferrite cores used for the signal transformers or signals, in general, have an application range from one kHz to many MHz, which can be as much as 300 MHz, and are mainly used in electronics as in RFID tags and AM radios.
Ferrite beads can also improve speakers' performance because they can increase the inductance and loss of the cables.
How Does a Ferrite Reduce Noise Interference?
When a ferrite bead choke is placed on a power line connected to an electronic device, it eliminates any high-frequency noise that exists on a power connection, or that has resulted from a DC power supply. The ferrite beads will saturate and lose their inductance when the DC increases. With such an important function these cores are important and widely used in many applications.
