LED Light Sources
Full area illumination is not always necessary. In some situations, accent lighting with optimal optoelectronics may be a more sensible approach. From indicator LED bulbs to high-power LED arrays, Arrow has all the solid state components needed to match any required degree of light source integration. We can also provide specific advice and support. For every possible lighting specification, we offer the right LED solution, including high-power LEDs, high-brightness LEDs and LED modules. Selecting the desired colour and luminous flux is simplified by our LED binning scheme. Thermal management and safeguarding against moisture and other factors, such as dust, are important considerations for using LEDs both indoors and outdoors. Arrow is committed to LED lighting and carries products from industry leading LED manufacturers.
Luminous flux is a physical quantity expressed in units of lumens (lm). It is a measure of the total amount of visible light emitted in all directions, and it indicates the brightness of a lamp. A 60-watt incandescent lamp typically produces a luminous flux of around 600 lumen, and LED modules can produce the same luminous flux from just 8 watts. Luminous flux ratings provide a realistic way to compare "warm white" light sources, since factors such as light colour or concentration of the light beam by reflectors are significant in determining the luminous flux.
The lifetime of an LED bulb is specified as the time required for the luminous flux to drop to half of its initial value with a new LED. The brightness of LEDs decreases gradually over time, depending on the semiconductor material, heat dissipation and power source. Luminous power may also drop due the failure of individual LEDs. LED lifetime is usually specified in operating hours. Standard LEDs have a lifetime of approximately 100,000 hours in continuous operation, corresponding to around 11.5 years, or even more. The lifetime of high power LEDs is approximately 25,000 to 50,000 hours. For comparison, the lifetime of incandescent lamps is around 1,000 hours.
LEDs offer an impressive spectrum of colours. They can convert electrical energy into red, yellow, blue or green light. Any desired colour can be generated by mixing light from different sources. The colour of light emitted by LEDs is specified by its wavelength in nanometres (nm).
The values listed below are commonly used. The larger the value within a particular colour range, the deeper the colour. Green and yellow are the most intense.
- Blue: 450–500 nm
- Green: 500–570 nm
- Yellow: 570–590 nm
- Red: 610–760 nm
All of the problems associated with generating warm white light from LED modules have now been overcome. Different tones of white light are expressed in terms of colour temperature, which is measured in degrees Kelvin (K). The colour spectrum of “white” light ranges from soft warm white at approximately 2,600 K to intense blue-white light at approximately 5,000 to 7,000 K, equivalent to daylight. The large colour spectrum that can be achieved with LEDs makes for more and more possible applications in addition to lighting.