Components of a Halogen Light Bulb

Halogen light is desired for the more natural light it gives off, and the long life of the bulb. Though they get much hotter, halogen bulbs have the advantage of the halogen cycle. This makes them far more efficient than incandescent bulbs and have three times the life span. Still, the basic hardware of a halogen light is the same as an incandescent.

The Bulb

A large bulb that comes with a halogen light is mostly cosmetic. The true action in a halogen light bulb happens in a much smaller, tube shaped envelope. This is made of quartz, or a special glass with a higher than normal melting point. It’s filled with an inert gas like argon or xenon and a halogen, which gives the bulb its name. Halogens are five very reactive elements, fluorine, chlorine, bromine, iodine or astatine, that bond very strongly with other atoms, like tungsten. The halogen usually found in a halogen bulb is iodine.

Tungsten filament

The filament is a double coil, and heats up and glows when an electric current is passed through it. Heating up and glowing is simply a function of how fast the tungsten atoms vibrate. A bulb with a longer filament has a higher wattage than a bulb with a shorter one, simply because of the amount of atoms the filament has.

Tungsten is the usual element for light bulb filaments because it’s easy to draw into an extremely thin wire and has a very high melting point of over 6,000 F. Even a halogen light doesn’t get that hot -- it gets to about 5,400 degrees F at its hottest -- so the tungsten doesn’t melt. Still, the heat in even a regular incandescent bulb causes the tungsten to evaporate and blacken the inside of the bulb, but in a halogen light bulb the tungsten reacts with the halogen and is redeposited on the filament coil, which helps extend the life of the bulb.

Electric circuit

The electric circuit is connected to the filament and allows an electric current to pass through it to the point where it glows. The current travels up one of the wires, across the filament and then travels down the wire on the other side.

Pin

The pin anchors the electrical wires into the stem of the bulb and helps bring the current up and down the electrical circuit.

Base

Halogen light bulbs can come with bases that can screw into the socket of a light fixture. The screw base is usually insulated with vitrite.

Contact

When it touches the contact of the light fixture, the contact of the halogen light bulb allows electricity to flow through the electrical circuit and cause the filament to glow.