LED lighting has become increasingly popular over the years due to its lower usage costs, energy efficiency and better performance when compared to conventional lighting technologies.
This safe, long lasting and robust form of lighting is used in a wide range of settings including domestic households, traffic light systems, supermarkets and retail outlets, intelligent building systems, automotive industries, schools and colleges and communication technologies.
Examples of LED lights include Panel lights, Down lights, Linear Tubes, 2D and Luminaires.
Background: History of LED lighting
LED stands for ‘Light-Emitting Diode’ and has been around for many years, making its first appearance back in 1962. The first series of LED lights were used in electronic display devices and laboratory equipment before expanding into consumer devices such as radios, telephones, calculators and televisions.
The first LED was a visible-spectrum ‘red’ light and was used in indicator lamps but the addition of visible, infrared and ultraviolet LED’s broadened its reach. LED lighting soon appeared in devices, e.g. digital clocks, transport industry, commercial buildings and environments.
A single LED light is comprised of a series of electrons that together with a semi-conductor material produces a beam of light whilst releasing a small amount of heat, via a heat sink, at the same time.
They are mainly used for lighting and illumination, from domestic to commercial/industrial use. LED lighting is available in different colours and wavelengths depending upon your need.
Types of LED lighting
LED lights are available in different colours and wavelength spectrum, from infrared at one end through to visible red, green and blue and then ultraviolet at the other end.
General-purpose lighting as used in domestic or commercial environments requires white light. There are two ways of achieving this:
- By mixing the light from red, green and blue LED’s, using electronic circuits to control the blend. These are known as RGB LED’s
- A short wavelength blue LED is coated with different coloured phosphor materials that convert this from a short wavelength to a broad-spectrum white light. This process is known as the ‘Stokes shift’
The broader the spectrum of white light emitted the higher the colour rendering index (CRI) of the LED light. This is important in terms of now natural an object looks when placed under a lighting source. LED lighting tends to give a higher CRI score as compared to fluorescent and incandescent lighting.