Question

In relation to LED technology

1) outline the problem the technology solves?

2) WHAT DOES THE TECHNOLOGY DO?

3) Identify the major material property requiremens ( strong, conductive, corrosion resistant, etc) and design constraints (eg. must be molded, must function within a temperature range, etc)

Answer 1

(1) LED technology solves the problem of energy wastage as it doesn't waste energy in form of heat since it produces cold light in contrast to conventional incandescent lamps those produce energy in the infrared region using up a lot of energy in the form of heat. This serves two purposes: (i) the energy consumption is low in case of LED lamps, and (ii) the light does not heat up the room undesirably.

(2) Light-emitting diodes (LEDs) are solid-state devices that convert electric energy directly into the light of a single colour. They use "cold" light generation technology, in which most of the energy is delivered in the visible spectrum. This is why LED technology helps to generate brighter light at the consumption of a lower amount of energy as compared to the conventional lighting technology.

(3) The centrepiece of a typical LED is a diode that is chip-mounted in a reflector cup and held in place by a mild steel lead frame connected to a pair of electrical wires. The entire arrangement is then encapsulated in epoxy. The diode chip is generally about 0.25 mm square. The shape, or width, of the emitted light beam, is determined by a variety of factors: the shape of the reflector cup, the size of the LED chip, the shape of the epoxy lens and the distance between the LED chip and the epoxy lens. The composition of the materials determines the wavelength and colour of light.