Friends, you must have seen a cylinder connected with your laptop, computer, or TV cable. As in the photo below, there is a black cylinder.
But if you are asked what this cylinder is, its technical name, and how it works. Then only a few people can answer it. But this question is very important because many questions were asked in the interview related to this cylinder.
So let’s understand what this cylinder is called in technical language and why it is so important?
What is black cylinder on charger?
The black cylinder you see on the charger is technically called Ferrite Bead. It filters high-frequency signals or noise from our supply or main signal.
Friends, if we understand the working of ferrite bead in simple language, then its job is to stop the high-frequency waves and noise. If we talk about noise, these are unwanted signals mixed in our main signal and disturb our main signal.
Now the question will come to your mind that how ferrite bead filter noise and high-frequency signals.
How does Ferrite Bead work?
Friends Ferrite Bead works on Faraday’s Mutual Induction Principle. If you don’t know what Faraday Mutual Induction law is, then let’s take an overview of this.
Faraday Mutual Induction law: Whenever a conductor is placed in a varying magnetic field, an EMF is induced.
Now, if we talk about ferrite bead, this is made of a magnetic material. A high inductance coil is placed inside this cylinder.
When high-frequency waves pass through this coil, an emf is induced, and the current start is flowing with faraday’s law.
Note: This current is induced by noise and high frequency.
Friends, this current which is generated from noise and high-frequency waves, it completely converts noise into heat energy and thus removes noise and high-frequency waves from our main signal.
Now the question will come to your mind: How does noise mix in our main signal?

Friends, when current follows in a conductor wire, an electromagnetic field is induced around it. This electromagnetic field acts like an antenna, meaning that all the mobile radio signals around us are observed and put in our conductor wire, due to which noise comes into our main signal.
What is Effect of High Frequency and Noise on system?
- High-frequency signal:
Friends, our equipment’s made for work on 50Hz frequency. When higher frequency passes through our equipment, then it can damage. - Noise in signal:
Due to the high frequency, noise can come from the signal. The basic definition of noise is that these are unwanted signals in our system. Due to noise, it is possible that our output is not clear, like in a tv screen that can flicker or blur or noise in voice or other disturbances possible.
3. Battery charging:
Due to high-frequency signals or noise, it may be possible that our battery may not charge or maybe a very slow charge.
So, friends, we understand what a ferrite bead is and the working of the ferrite bead. Now let’s understand the types of ferrite bead.
Types of Ferrite Bead?
There are two types of ferrite bead:
- Chip ferrite bead
- Wire wound ferrite bead
Chip Ferrite Bead:
This is the traditional method to suppress frequency and filter Noise. This is used only for the low current rating. If a certain amount of current flows, then it can damage easily. Heat and atmosphere temperature also affect its performance.
Wire Wound Ferrite Bead:
This is used for a wide range of frequency. It has high current ratings. Nowadays mostly used
So, friends, we hope you understand what ferrite beat is and how it works. If any question is left, you can comment below or send the inquiry to us on Instagram “Electrical Dost.”
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Thank You 🙂
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