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LED Arrays

There has been a lot of controversy surrounding LEDs of late and this page presents the engineering facts as we perceive them.

LED production requires huge investment by their manufacturing companies 

Smaller niche users such as head torch manufacturers must fit in with this overall development.  

Most Western manufacturers tend to use the same LEDs.

It is what they do with them that matters!

The Myths (heavily promoted by some)

LEDs give cool light 

Nothing could be further from the truth.

LEDs produce almost as much heat as halogen bulbs.

The light emitted from the LEDs is without heat

Therefore the heat has to be conducted away from the LEDs by other means

LED service lives are >100,000 hours 

     These service lives  may be achievable under laboratory conditions but NOT in  any head torch which             employs arrays. 

So why use Arrays? 

Customers wanted LED light at a time when individual LEDs did not produce sufficient output on their own.

Arrays could be combined with conventional filament bulbs to give hybrid systems. These are still popular as retro-fit to extend the model-life of older lights. We sell many ourselves.

What is the disadvantage of Arrays?

HEAT which has to be conducted away from the LED junction by the input leads. 

The problem is compounded by the high thermal resistance of the plastic shell of most headpieces.

This is in series with all of the other thermal resistances

 We minimise these thermal problems in our LED/Reflector assemblies in two ways

1. The LEDs are widely spaced around the periphery rather than tightly in the centre.
2. We realise that our customers tend to use their arrays a lot more than others (an FX3 can run them a LOT harder than a few AA Alkalines!) so we put less current through ours than some other manufacturers.

LEDs do not last forever!

Traffic light manufacturers have a much bigger market than most but even their arrays exhibit the inevitable failure of a proportion of LEDs. 

Obviously those which are used most fail first as is illustrated here (you will notice this effect when bored at traffic lights)

How can these problems be Avoided?

Technology has moved on!

Our NOVA Headtorch employs a Luxeon LED in a headpiece which removes heat 5 times more effectively (1/5^th Thermal Resistance) than conventional headpieces.

Go to NOVA