Efficiency of various light sources
Submitted: Friday, Jan 14, 2005 at 15:12
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phil
Hi all,
There has been discussion recently about use of LED lights.
I have come across a useful site which has a wealth of info about all types of lighting systems.
http://members.misty.com/don/light.html
Amongst some of the useful info I found is data on efficiency of various types of light.
240v incandescent 17 lumen/watt
12v halogen 21 lumen/watt
White white LED 33 lumen/watt 2004 data. Improvement expected in 2005
Compact Flouro 45-60 lumen/watt
32W T8 tube flouro 80 lumen/watt
As can be seen LEDs still have a long way to go to equal the efficiency of flouros
Interestingly the spectrum of flouros and white LEDs better matches the response of the human eye in low light conditions so the gain over incandescent lights is even greater in other than
bright light.
Phil I
Reply By: MaxMod - Friday, Jan 14, 2005 at 22:57
Friday, Jan 14, 2005 at 22:57
The real benefit of LEDs is where you want the light focussed in one direction, because that's inhrently the way they work without needing a reflector - that's why they're popular for torches and tail lights.
The biggest LED available today is 5 watts, but it's pretty expensive.
Halogen efficiency depends very much on how hard you drive them - consider that a 50watt downlight is rated at 50watts at 11.3 volts - apply 14 volts in a car and it will be a lot more efficient, but it may only last 20 hours.
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Reply By: Noosa Bushtrackers - Saturday, Jan 15, 2005 at 16:25
Saturday, Jan 15, 2005 at 16:25
We replaced the globes in our caravan reading lights, with 21 LED globes and now instead of having a lot of heat produced using 3amps per light, we now have No heat and only use 0.1amps per light.
The LED do not give a wide area of light, and from a distance you wouldn't think you could read under them, but when under them they give a brilliant white light that makes reading very easy. They are really the way to go in a caravan situation where you are running off batteries and
solar power.
I am now looking around for something like an LED reversing light with about 60 LEDs so that I can replace the exterior light with one or 2 of these.
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Follow Up By: Bob Y. - Qld - Sunday, Jan 16, 2005 at 12:55
Sunday, Jan 16, 2005 at 12:55
Brian,
Have a look at January edition of Silicon Chip mag. They have a article about a 48 LED "prawn light", that with modification, may work as a reversing light.
Hooroo...
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