How compact fluorescent lamps (CFL) Works?

When an atom absorbs energy from any external source, it goes to excited state. When it come back to ground state it emits that energy in Ultra violet, Infrared or visible region. Normally tungsten filament emits light in uv region when it jumps from excited state to ground state. These photons hit the phosphor coating the inside of the fluorescent tube, and this phosphor creates visible light.

A fluorescent bulb uses a completely different method to produce light. There are electrodes at both ends of a fluorescent tube, and a gas containing argon and mercury vapor is inside the tube. A stream of electrons flows through the gas from one electrode to the other. These electrons bump into the mercury atoms and excite them. As the mercury atoms move from the excited state back to the unexcited state, they give off ultraviolet photons. These photons hit the phosphor coating the inside of the fluorescent tube, and this phosphor creates visible light.

Electrical ballast is a device intended to limit the amount of current in an electric circuit. This is used in clf to excite atom in the electrodes at low power.

Advantage of using CFL bulbs are,

·        use up to around 67 percent less energy with no loss in light

·        last eight to 10 times longer; and

·        deliver up to seven years of warm, inviting light

·        Produce 90% less heat, while producing more light per watt.

So, in short, fluorescent lights make their energy in a three-step process:

1.     Electrodes take electrical energy from the power supply and generate moving electrons.

2.     The moving electrons collide with mercury atoms in the tubes to make ultraviolet light.

3.     The white phosphor coating of the tubes converts the ultraviolet light into visible light (that we can see).

What's inside a compact fluorescent lamp?

1. Connection to power socket

2. Transformer circuit

3. Electrodes

4-6).  Glass tubes with white phosphor coating inside.

A toxic issue

All CFLs contain mercury, a neurotoxin that can cause kidney and brain damage. Mercury is the most efficient element for the generation of ultraviolet light. While the amount of mercury used in a CFL has decreased in recent years, a small amount is still needed.

What to do if a CFL breaks

1. Ventilate

Open a window shut off the air-conditioning and leaves the room for at least 15 minutes.

2. Clean-up

Wear gloves and never use your bare hands. Do not use a vacuum cleaner or broom if possible – scoop up glass fragments and powder with a piece of paper or cardboard, and place them in a sealed container or plastic bag. Use sticky tape to pick up small fragments. Bedding or clothes that come in contact with mercury should be thrown away and not washed.

3. Disposal

Double-bag all the broken pieces and cleaning materials in a sealed bag and dispose of them properly. It would be better to take them to a recycling centre capable of handling hazardous materials, but in the absence of such, it should be marked as clearly as possible.

4. Wash your hands

To state the obvious, this is to make sure that there is no residual mercury.

5. What not to do

       Do not use a vacuum cleaner or broom – the vacuum will put mercury into the air, and a broom may just spread it around. Never pour it down a drain. Never wash mercury-contaminated clothing or items as it may contaminate the machine and/or pollute sewage.