MAKING LIGHT
How the most common type of energy-efficient bulb produces light
1 BASE
This is where the bulb is attached to the light fitting, typically with either a screw or bayonet fitting.
2 BALLAST HOUSING
This section contains and protects the ballast, which is what enables the light to function.
3 BALLAST
When voltage is applied to the ballast, the mercury vapour is energised.
4 ARGON AND MERCURY
Both elements are energised, which starts the process of creating light.
5 ULTRAVIOLET LIGHT
The excited gases create ultraviolet light, which collides with the tube to create visible light.
6 COVER
The cover protects the inner workings and makes it safe for handling.