ELIF: Why do flurecent lights flicker when they are turned on?
In: Engineering
A fluorescent light contains a gas. When electricity is applied the elections collide with those of the gas which causes an emission of light.
When the light isn’t used for a while the gas cools and becomes a liquid on the side of the tube.
Once the tube gets warm enough all of the liquid is a gas again but it takes a little while. So the light appears to flicker in the mean time.
Certain electric lights, such as fluorescent and sodium vapor, rely on an electric current flowing through a gas to emit light (UV in the case of fluorescent). That current can take a few tries to really be sustained as the elements heat up, so it flickers and dies a few times as it’s starting from a cold start.
Content of this type of lamp is not very conductive. You need to heat ends to create gas which poses less resistance, and then you need high-voltage kick so that it ionizes gas inside and makes it more conductive. Once lamp is operational, you don’t need such high voltage. There is simple analog circuit with mechanical starter that doesn’t know if lamp is ready to be started, it only repeatedly provides that high-voltage kick. So light goes trough multiple cycles until it successfully sustains current. It’s like dams, you need lot’s of water to destroy it, but then also small current flows trough. You need to divert the river if you want to rebuilt the dam.
See [this](https://www.youtube.com/watch?v=maniMjcvS7M) video showing you how process of starting fluorescent light works.
Latest Answers