Traditional neon signs are bright and dazzling but, if you get close to them then you will distinctly hear an annoying humming noise. However, modern neon LED signs look just as good and are noiseless.
No, neon LED signs do not make any noise. They do not have any parts that vibrate or output a high frequency to cause noise. However, traditional neon signs have transformers that output a very high frequency. So, a high-pitched tone could be audible to some people from traditional neon signs.
The following parts will explain topics related to this question. Such as why neon signs make noise, how do neon signs work, do neon LED signs make noise and how neon LED signs work.
Do neon LED signs make noise?
Neon LED signs are the new best thing that is replacing neon signs. Neon signs are known to make irritating humming noises. But, this issue is not present for neon LED signs.
Neon LED signs do not contain a transformer or a glass tube. So, the humming noise created by electricity is non-existent.
But there have been cases where neon LED signs might make a low noise if you use a dimmer to help you dim the neon LED signs. But, this issue is easily fixable. Incompatibility between your neon LED sign driver and the dimmer can cause noise. You can change the dimmer and find a compatible one that doesn’t make noise.
Sometimes, other devices near the neon LED sign may also create interference. To resolve this issue, you can try moving electrical devices away from the neon LED sign. And the humming noise due to interference will go away on its own.
Again, these issues are very rare and neon LED signs do not make noise usually. If you want to decorate your room with a dazzling neon LED sign then you do not have to worry about noise at all from neon LED signs.
How do neon LED signs work?
Neon signs were made in the 1920s and it has been popular since. But, there have many technological advancements that have upgraded the traditional neon signs.
The most popular and recent of this upgrade is the neon LED(Light Emitting Diodes) signs. It uses the technology of LED to replicate the look and feel of neon signs.
Traditional neon signs depended on a reaction between gases and an electrical current. But, in LED neon signs, electrons pass through a semiconductor that produces light.
The basics of LED is a special structure formed by specific semiconductor materials. The structure under special conditions can separate electrons. Electrons are divided into free electrons and bonded electrons. The reaction between these two types of electrons inside the structure produces light.
This video goes into the detailed process which creates light inside a LED.
The LEDs are placed nearby to each other in signs. So they produce a steady source of light like the effect of neon gas glowing inside a glass tube.
Light-emitting diodes are placed closely together and their light overlaps. This creates a steady source of light.
Why do traditional neon signs make noise?
Neon signs use electricity for power so they need transformers. Use of transformer means that electricity noise is always possible. The materials used for the neon signs such as the glass tubes may also make noise. This detailed answer gives three possible reasons why neon signs make noise. I will explain the reasons below.
1. Electrical and transformer noise
Neon signs are powered by electricity which is transferred through simple high-voltage transformers. Usually a transformer takes 120 or 240 volt 50/60 Hz line current, and bumps it up to 10,000 volts or so. Most of the time Alternating Current(AC) electricity is used. The current alternates between a high voltage in one direction and other direction.
The transformer itself also changes shape a bit when the sign is turned on, which causes vibrations at multiples of the line frequency. The transformer is also often mounted to the sign. So the whole sign may sometimes act as a sounding board and make certain noises even louder.
2. Glass tube noise
Secondly, the tube used for the neon sign itself might make some noise. Specially signs that are high power may make noise. Due to heat, the gas inside the glass tube makes causes the tube to expand and contract. This might cause low-frequency noises which might be audible for some people.
3. Defects in the insulation and lamination
Defects in the insulation may cause some electricity to leak out of the glass tubes and make noise. But, the noise volume should be low and you would only hear this type of noise if you stand close to the glass tube ends.
In some cases, lamination is used to protect the transformer. The lamination can vibrate and create buzzing noises. The lamination covering the transformer can vibrate if it is not enclosed by a shell.
How do traditional neon signs work?
Now we know why neon signs make noises particularly buzzing noises. So let’s understand the science behind the neon signs.
Neon signs were named after the noble gases that are filled in the gas tubes of neon signs. This scientific journal paper goes into detail about the history and use of neon signs.
It says that “neon sign is simply a vacuum glass tube fitted at each end with a metal terminal or electrode. Inside the tube is a small amount of rare gas[mostly neon]. Connected to the two electrodes is a source of high-voltage electrical power.”
An alternating current is applied to the electrodes which cause the neon atoms inside the tube to separate. Some of the atoms shed electrons to become positively charged ions. These go towards the negative electrode. The free electrons have a negative charge. The positive electrode at the other end draws these negative-charged electrons. When neon atoms, ions and electrons bounce around the tube, they collide with each other. And the ionized atoms recapture their electrons to become neutral again. This causes them to return to their original energy level. And in the process, they release a photon (particle of light) and causes them to give off a colored glow.
In simple terms, electricity is made to pass through the glass tubes filled with noble gases. And this causes light to produce. Each noble gas can only produce a specific color. Neon gas, which is the most popular used gas in neon signs, creates a reddish-orange light. Argon(another noble gas) produces green color. Different gases can also be mixed to create a color- gold neon signs use argon and helium inside a gold glass tube.
Verdict: only neon LED signs are noiseless
As we discussed above, due to the materials and structure used in the neon signs, they often make a humming noise. The transformers used in the neon signs create electrical noise. The humming noise can be lessened but not completely removed.
But, there are no transformers and glass tubes that can vibrate and create noise in neon LED. So, the possibility of humming noise from neon LED signs are very low.
Even in rare cases where there are humming noises, they can be easily fixable. Incompatibility between the neon LED signs and the external dimmer may cause noise. You can simply change and replace the dimmer with a compatible one.
If you want the look and feel of a neon sign but you are worried about the noise. Then you can opt for neon LED signs.
In bars and cafes, the use of neon signs can interfere with live music. Music gears can pick up the humming noise created by the neon sign and amplify it with the speakers. This problem does not have a cheap solution and you might need to invest in a power conditioner to rid this issue.
However, you can invest in a neon LED sign from the start for your bar, restaurant and cafe and never have to worry about this issue.