Lamps have moved on in leaps and bounds since Thomas Edison’s original incandescent design. Incandescent lamps function by means of a filament wire heated to a high temperature, whilst the filament is protected from oxidisation by means of an inert gas held in a glass bulb. A halogen lamp protects the filament by a chemical process that deposits metal vapour back onto the filament thus increasing its life. Fluorescent lamps function by running an electrical current through a gas. As the mercury vapour in the gas is excited by the electrical current, short wave ultra violet light is produced which then reacts with a the phosphor coating on the inside of the bulb causing it to fluoresce therefore producing visible light. The luminous efficacy or light to power ratio of LED lamps continues to get better as Diode technology improves at an exponential rate. Without a doubt light emitting diodes or LED’s are definitely the light source of the future. LED’s release energy in the form of photons otherwise known as electroluminescence which provide many advantages over incandescent or halogen lighting including lower energy consumption, longer lifetime, smaller size, improved physical robustness and faster switching.
