Tube televisions are now a thing of the past, they are almost nonexistent in our homes. Now we can only come across them in villages, summer houses or neighborhood tradesmen. Almost all of us have a memory with these tube televisions, which are one of the iconic items of the 90s and early 2000s (like putting your finger close to the screen and feeling the electric current).
If you have owned or used an old tube television before, you may have noticed that it sometimes makes a crackling sound when you turn it off. This sound could be quite frightening, especially at night when it was quiet.
To understand why, we must first understand how tube televisions work.
These types of televisions, which we call ‘tube television’, and whose name is CRT (Cathode-Ray Tube, Cathode Ray Lamp) televisions, circulate a very high amount of voltage electricity. So high that this voltage can reach 25,000 V.
The crackling sound is due to this high voltage used to create the images on the screen. These devices work by sending a beam of electrons from an electron gun in what we call the ‘tube’ to the phosphor-coated screen at the front. Electrons collide with the phosphors and cause an explosion, thus creating colors and shapes on the screen.
This information is in the pocket, what is causing the crackling sound?
A high voltage is applied to a metal plate inside the tube of the television to control the direction and speed of the electron beam. This creates an electric field that bends and focuses the beam (So if you put a magnet close to the tube television screen, you will destroy the television).
This high voltage is cut off when you turn off the TV, but not immediately, as it takes some time for the electrical charge to dissipate from the metal sheet and other components inside the TV. While the charged electricity in the television is discharged, some of the charge may leak out or leak through the gaps, creating sparks or electrical leakage.
It is these sparks that produce the crackling sound we hear.
(If there is heavy dust in the air of the environment where the television is located, this crackling sound is more likely to be heard when the television is turned off. As you know, dust mostly consists of dead skin pieces, this high voltage attracts them. Dust caught in the current can also cause a crackling sound.
At the same time, the temperature change can be the source of the crackling sound as it causes the metal plate inside the television to expand. In both cases, the result is due to electrical currents.)
So, does the high voltage that makes this crackling sound harm you?
As long as the crackling sound is not too frequent or loud, it will not harm the TV or you. It is a normal phenomenon that occurs in many electronic devices that use high voltages, such as fluorescent lamps or microwave ovens. However, if crackling sounds are heard frequently or very loudly, there may be a problem with the tube television.
How? If there is dust, moisture, or corrosion on high-voltage components that could increase the risk of sparks or short circuits. The same is true if there is a loose or damaged cable or connector that could cause leakage or overheating. These problems can damage your TV and even cause a fire hazard.
Can the crackling sound be prevented from tube televisions?
They need to be kept clean and dry to prevent or reduce crackling sounds from tube televisions. Avoid placing near sources of heat, humidity or magnetic fields, such as radiators, humidifiers or speakers.
The television should not be touched or moved while it is on or shortly after turning it off, as this may distort the electrical charge and cause sparks. Of course, since we didn’t know these things, we always used to run the finger on the electric screen.
Today, tube televisions seem to have disappeared; LCDs, LEDs or OLED TVs are more common. We can sometimes miss these televisions with a nostalgic feeling, but when we remember the old technology and how much anxiety it requires, it would not be wrong to say that there are no more tube televisions…
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