What’s the difference between LEDs and halogen bulbs?
High power LEDs are non-linear devices. If a low voltage is applied to an LED it does not conduct. As the voltage increases, it passes a threshold value when suddenly the LED starts to emit light and the current sharply increases.
If the voltage continues to rise by even a small amount, the LED can overheat and burn out. The trick is to operate the LED in the narrow band between full off and full on.
Graph 1: Useful operating area for high power LEDs [Ta=25°C]
To run the LED in the safe operating area (shown in red in the graph) you need an LED driver, a special type of power supply that regulates the output current rather than the output voltage.
A short overview of product specifications
The main reasons why LED lighting has seen such a rapid growth are lifetime, efficacy and light quality. An LED is a solid state device; it contains no filaments that can burn out or gas deals that can leak so it has a lifetime of up to 50 times that of conventional lighting. For applications where it is difficult, time consuming or expensive to change the lamp bulbs (e.g. street lighting, high ceilings, waterproof lights) LEDs offered immediate advantages that outweighed the initial higher cost.
LEDs are much more efficacious (lumens-per-watt efficiency) than conventional tungsten or halogen lights. A 100W light bulb can be replaced with a 15 watt LED with the same light output. The savings in electricity costs over the lifetime of the lamp more than cover the initial higher cost of the LED.
Finally, the quality of light can be fine-tuned with LEDs. A white LED made from multiple LED chips can have the odd red, blue or green led chip added to give any desired overall mixed light colour (for comparison: think of all of the variations of white paint you can buy, but with a “hint of a tint” or in “pastel shades” – very small changes to the basic white can make a big difference to the feel of a room). LEDs open new opportunities to make our homes, work places and public areas more welcoming, comfortable and relaxing places to be.
RECOM Lighting offers more than drivers
RECOM Lighting offers not just standard lighting products such as display lighting, LED drivers and complete turnkey solutions, we also offer a bespoke custom service. If you have an existing luminaire that you want converted to LEDs, we can build you a custom light engine that will drop straight in. If you have an idea for an LED lamp, but need someone to prototype it and to manufacture it for you, we can help.
Relevant certificates and norms
There is some confusion as to which certificates and norms apply to LED lighting. Many standards were originally written to cover conventional light sources and do not translate well to the different technology of solid state lighting.
There is no overall European directive that is equivalent to the American Energy Star or UL8750 safety certifications, for example, although organizations such as Zhaga, CEN and CELMA are working hard to create industry-wide standards for the European markets.
High quality LED drivers
LEDs have long lifetimes if powered by a quality driver. If the driver electronics are sub-standard or does not match the LEDs, then the LED lifetime can be very short – either the driver fails or the LEDs are overdriven until they burn out. For the average user, it is very difficult to assess the quality of the driver. Just looking at the case does not reveal the quality of components used inside and many driver datasheets are incomplete, misleading or downright false. Apart from testing the LED driver for at least 6 months before you buy, the only way to be sure of the driver quality or that the driver is truly compatible with the LED load is to buy from a trusted source. RECOM Lighting offer a no-quibble three year warranty on all of their products and a five-year warranty on most of their drivers.