COB LEDs and POWER LED are distinguished by excellent luminous intensity in the smaller sizes now available on the market.
This feature means these light sources can be integrated into very compact luminaires with unique performance, very high peak beam intensity (candela) and delivered lumens of 150lm to 4000 lm. These light sources are characterised by lumen maintenance at high operating temperatures due to improved efficacy at high temperatures and better optical stability over time.
A LED array has a number of small Chip-on-Board (COB) LEDs positioned into a clear pattern or array. There are a number of advantages associated with this method.
For example, the heat sink requirements of the luminaire are reduced as the LEDs are spaced more widely and are also of a lower wattage, allowing a slimmer flatter luminaire design.
Also, the individual LEDs are smaller so that the optical control is improved, allowing tighter narrower beam optics and the possibility of using lenses in combination with reflectors.
In addition, when working with beam-spreading optics and wall-washing panels it is possible to achieve a wider spread of projected light onto the wall and an even illuminance over a large area. The ability to organise the arrays into different shapes also presents the possibility to create additional visual interest or to meet specific lighting requirements.
Further benefits are realised when working with diffuse panels and frosted luminaire optics, as the separated configuration of the light source leads to a more even distribution of light across the surface of the luminaire.
There are also some disadvantages with this approach, the obvious one being that the combined luminaire optics will occupy a much larger area and this will impose some restrictions on the design of the luminaire.
LED modules are complete LED units that are designed to be replaceable at the end of their life, in the same way as a traditional light source can be replaced. The major benefit of using LED modules is the opportunity to replace the product at end of life, or to upgrade the luminaire to newer, more efficient LED light sources as they become available.
Typically a LED module comprises a LED COB (Chip-on-Board) product, which is mounted on a carrier device. The LED module is twisted or screwed onto a holder which is, in turn, mounted on a heat sink within the luminaire.
Generally speaking, the use of LED modules results in additional thermal losses, compared to using bonded types of LED light source. This will result in a slightly lower final efficacy, compared to bonded light sources. However the design of the luminaire and use of a thermal compound to facilitate improved heat transfer can mitigate this disadvantage to a very great extent while retaining the benefits described above.
Some LED modules offer tool-less replacement, while others require the use of a screwdriver.
The term LED module encompasses a wide range of different types of product, many of which mount onto a Zhaga compliant base or footprint. Zhaga is an international interface specification that enables interchangeability of LED light sources from different manufacturers. Zhaga compliance therefore provides customers with a wider choice of light sources through the life of the lighting installation.