Recent Changes - Search:

If linking to pages within the site, please do so in the form Group/Page e.g. News, to avoid problems when viewing this box from inside another group

MPS

Resources

PmWiki

*Lean Skin


Stats since 09 Jan 13:
Page hits:
Total hits:
Now online: 1


If linking to pages within the site, please do so in the form Group/Page e.g. Main/News, to avoid problems when viewing this box from inside another group

Next Meet

"Wild Camping"

1st - 3rd March 2013

Next Social

AGM. Portland D136.
map

Thursday 14th March
8.00 pm

If you don't want this for a time, please comment it-Fabian !Next Ice Climb

Manchester Indoor Ice Wall
Friday 1st December at 8:30am

If you don't want this for a time, please comment it-Fabian !Next Climb

LEDs are made of semiconductors. When an electric current is passed through the semiconductor it emits light photons. The type of semiconductor defines the colour of the light. They only produce light on one frequency (except white LEDs). Differing from incandescent light bulbs that produce everything from infrared to UV and the colour is controlled by what colour you paint the bulb. The photons in LEDs are generated by electrons jumping quantum energy stat... blah, blah, blah... Who cares? Click (http://electronics.howstuffworks.com/led.htm)if you do.

The advantages of LEDs over bulbs are:-

  • They are plastic and not hollow and therefore very hard wearing
  • They don't get hot and therefore do not burn out
  • No filaments, so cannot get broken, by dropping your torch for example
  • Have 100,000 hours average life, thats approximately 11.4 years continuous burn time
  • Very energy efficient as they waste very little heat

Disadvantages:-

  • They produce diffuse beams, general lighting, cannot focus like a MagLite
  • Torches are expensive

There are several types of LEDs:-

  • Boring LEDs These can be found on the front of TV's, keyboards, dishwashers, clocks, digital watches, stereos and fighter jets. They produce very little light and have no use as torches. They cost a few pence each or even less.
  • Ultra Brights Commonly found as key ring torches, lighting in buildings, frequently, for some reason in the floor and in computers belonging to geeks. Several of these can be combined together to create powerful torches (http://en.petzl.com/petzl/LampesGammes?Gamme=54), (note the torch has a halogen bulb for focus and long distance) or emergency torches such as the Petzl Tikka. They predominantly are availiable in white or blue. They cost about 3 apiece.
  • Luxeon The latest LEDs on the market, very powerful obtaining power outputs of 1-5 Watts. They, unlike other LEDs can be focused into a beam. They are found in very expensive lights, predominantly used in diving and caving. (http://www.princetontec.com/products/index.php?id=21&type=0&use=2)The LEDs cost around 10-15 each.
Edit - History - Print - Recent Changes - Search
Page last modified on September 26, 2007, at 03:29 PM