The incandescent lamp was invented by Thomas Alva Edison. Light is produced when current flows through a filament of resistance material to heat the lamp. Incandescent lamp is cheap, fast starting, small, easy to install, and has good warm color, but its life span is relatively short and is very sensitive to voltage change.
1. Filament - is usually made of tungsten
2. Gas - is a mixture of nitrogen
3. Lead-in wires - are made of copper which carry the current to the filament
4. Exhaust tube - discharges air during manufacture and releases inert gas into the bulb
5. Bulb - is usually made of glass. In some cases, hard glass is used to withstand higher temperature and to avoid sudden change in temperature.
6. Mica disk - is used to reduce the circulation of hot gases into the neck of the bulb
7. Fuse - is used to protect the lamp in the filament arc
8. Base - is a typical screw base. One lead-in wire is soldered to the center contact, and the other to the rim of the base shell which is made of brass.