BASICS 2 of 19

Incandescent

Halogen

Incandescent Lamps:
In an incandescent filament lamp an electrical voltage (similar to water pressure) pushes an electrical current (similar to water flow, measured in amps) through a filament made of tungsten wire. Because the filament has a resistance, it heats up and emits heat and light. The hot filament typically converts about 6%-8% of the electricity into light; over 90% is wasted as heat!

Halogen Lamps:
In a Halogen lamp the inside of the bulb is filled with a halogen gas which participates in a chemical cycle to keep the filament intact even though it is burned hotter. Halogen lamps last quite a bit longer than regular incandescent lamps. They are also more efficient: typically 10% to 12% is converted to light.