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Do You Know Why Are There Small Cylinder On The Power Supply?

Wondershare Recoverit Authors

Jan 27, 2024 • Filed to: Answer Hard Drive Problems • Proven solutions

Everyone is using laptops these days for various reasons. The laptop can run without a plug for few hours, but after some time, you need to charge it. The device comes with a power supply cable that has a cylinder connected at the end.

We all are very well aware of the cables that are connected to laptops or another electronic devices. But we do not become aware of the use of cylinders in the power supply.

In this article, we discuss the use of the small cylinder on the power supply. Also, we will discuss in detail why it is important and its history.

Just keep reading!

Part 1: What Is The Small Cylinder On The Laptop Charger?

Are you wondering what the cylinder on the power supply of the laptop charger?

Well, the cylinders on the power supply are nothing but ferrite beads. This is a special type of choke that suppresses the high-frequency noise in electronic circuits. It is a semi-magnetic substance that offers ferromagnetic properties.

cylinder at the end of charging cable

Basically, the ferrite bead prevents electromagnetic interference (EMI) to and from the device. Further, the cylinder also reduces radio frequency interference (RFI) which stops the signals to from interfering with other nearby electronic devices.

History of the cylinder on the power supply

In the old times or previously, most DC power supplies were of linear in nature. It means there is the presence of a transformer in the power supply box that reduced the voltage and a rectifier circuit. Also, it converted AC to DC. But, such boxes make the device bulky and heavy.

Also, in previous times the electronic devices were really inefficient and wasted more power. But yes, they were not noisy, which they had a very low electromagnetic noise.

In recent times these boxes got replaced with Switched-mode power supplies. With this, there is no more transformer in them but contains a high-frequency oscillator. This makes the laptops and other electronic devices highly efficient as well as lightweight.

The only disadvantage of frequency oscillators is the extra EMI or generation of electrical switching noise.

Part 2: What Is The Use Of The Cylinder In Charging Cables?

The cylinder in the charging cable or ferrite bead creates a low-pass filter on the wire which further eliminates the high-frequency noise. In simple words, we can say that it stops the wire from behaving as an antenna and eliminate interference from other surrounding devices.

What is a ferrite bead or cylinder is made up of?

Basically, the cylinder is made of ferrite, which is a compound made of a mixture of oxide of iron and other useful metals. To make a cylinder, the ferrites are placed inside a plastic or plastic material. This keeps the ferrite safe and protects it from further oxidation due to the presence of air.

 Ferrite bead in charging cable

What is the use of a small cylinder on computer cables?

This small cylinder on the power supply of electronic devices is also known as ferrite choke or ferrite bead. It’s simply a hollow cylinder that act as a semi-magnetic substance.

Wondering what the use of ferrite bead is? Its main aim is to reduce electromagnetic interference (EMI) as well as radio frequency interference (RFI).

These types of interferences can cause your electronic devices to buzz, speakers to chirp, and monitors to flicker. In the cylinder, EMI and RFI signals get converted into heat, and the ferrite atoms block them.

Thus, the ferrite core or cylinder eliminates the disturbance and improves data stream quality. So, to protect your device, the ferrite bead comes in handy.

Note: But, in Apple products and in new laptops, these cylinders are missing. It is possible that there is already a device used inside the device to fix the issue of signal interference.

What does it do?

  • The cylinders work as accumulators. It means they store a few milliseconds’ worths of power and maintain data flow through the cable while minute fluctuations occur in the power supply.
  • The ferrite beads are designed to reduce electrical interference with other nearby electrical sources.
  • The cylinder in the power supply ensures the accuracy of data transmission.
  • We can say that the cylinders are a type of fuse whose sole purpose is to protect the devices they connect. If one electronic device experiences a power surge, the cylinder prevents the surge from damaging it.

Part 3: Is Ferrite Bead or Small Cylinder in Power Supply Necessary?

For electronic devices, controlling the EMI is a must to keep it running without any damage. Also, controlled EMI can protect the various components of laptops or other similar devices. On the other hand, if there is no control on EMI, then the high-frequency noise levels will damage your device.

EMI or Electromagnetic interference occurs when one electromagnetic field of a device interferes with another. Some common reasons for EMI are switching-mode power supplies, motor brushes, arc welders, and electrical contacts. And, all these can cause problems not only to your device but to nearby devices too.

Sometimes the high voltage surges generate electrical noise that can damage hardware and can corrupt the data. Therefore, to counter these threats, ferrite beads are a must in electronic devices.

Final Words

Every component in the device has some purpose, and the same goes right for the small cylinder on the power supply. You might be using the laptops for years without noticing the use of this part in your device.

The small cylinder is termed a ferrite bead whose concept is very much similar to an antenna. The charging cable receives as well as transmits the signals, and the small cylinder protects the EMI interference. In the above article, we have discussed the use of the small cylinder on the power supply in brief.

Recoverit author

Theo Lucia

chief Editor

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