Switching to LEDs

Well i've decided to give up on my search for a decent led bulb, as i recently got a new cf bulb and the performance is stunning, unlike the old one this one lights up instantly to full brightness, puts out a good light colour, and its very bright. In short its identical to the 60w incandescent its designed to replace, except it uses a 3rd of the energy and lasts about 5 times longer.
My only gripe with cf bulbs now is that they aren't dimmable. And it turns out that its perfectly possible to make dimmable ones, just no one can be bothered to manufacturer any.
 
I've got a feeling that if you dim them, it can only be done in a linear fashion? By that I mean if you want a lower light output, the energy usually used by the bulb is just wated as heat. Firstly its hard to get rid of in a small space and secondly it kind of goes against the nature of the product. Conventional filament bulbs and LEDs can be dimmed efficiently with PWM (a dimmer switch works by breaking the AC cycles creating a sort of PWM), yes, LEDs can be dimmed properly, its only the AC powering circuit that prevents it.
 
I found some dimmable cf bulbs available in the us, but not in the uk. Even if they did dissipate more heat, it would still be a lot less than an incandescent would produce i should think.

I'll go and find the link.

Edit: Thread here.
 
Joe42 said:
In short its identical to the 60w incandescent its designed to replace
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Do you have a link to the one you bought?

I tried one that was supposed to replace a 100W bulb so I bunged it in the cooker hood expecting it to be reasonable but it was dimmer than the 60W bulb we took out!
All the energy efficient bulbs I've seen have been poor compared to incandescent and the claims of equivalent wattage seem to be BS at best.
 
Mr Joshua said:
Do you have a link to the one you bought?

I tried one that was supposed to replace a 100W bulb so I bunged it in the cooker hood expecting it to be reasonable but it was dimmer than the 60W bulb we took out!
All the energy efficient bulbs I've seen have been poor compared to incandescent and the claims of equivalent wattage seem to be BS at best.
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Just had a look, it a general electric 20w one, think it came from Tesco.

I think its just one of the new generation ones, and many places are still selling older ones, but i expect in a year or so's time they will all be like that.

Edit: Here it is. The 20w version, not sure if it was the long life one but i expect they are both the same. It says 100w equivalent but i'd say its closer to 60w equivalent.
 
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VeNT said:
how long do those normaly last (the LED ones)?
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I don't think they have really been around long enough for anyone to experience them dieing, but i think for a normal led its something in the region of 10 years.
They don't really die as such either, just get dimmer. Could vary a lot depending on the type of led used but i bet they will all last at least 10 years.
 
A lot of power LEDs seem to quote "life expectancy of more than 100,000 hours". Don't know what that equates to in normal use, but unlike normal bulbs and probably CFL as well, LEDs don't get so stressed when first being switched on (filament bulbs require 10x the power to initially start from cold).
 
http://compoundsemiconductor.net/articles/news/10/12/3/1

http://www.zled.com/_homepage/home_eng/asp/news_content.asp?news_idx=31

Seoul's single-die source packs 240 lumen punch

5 December 2006

A Korean LED maker claims to have launched the world's brightest single-die white LED light source.

Seoul Semiconductor says that its latest LED technology has resulted in a single-die white source that can emit up to 100 lumens per Watt. Importantly, Seoul is claiming the high efficacy figure for chips that operate at the 350 mA drive current that is required for general illumination applications.


The new "P4" emitter is claimed to produce 240 lumens at its maximum drive current. Two types of commercial device are available – one operates at a typical efficacy of 100 lm/W at 350 mA, and the other is rated at 80 lm/W.

"Conventional LEDs have been known to emit more than 100 lumens with several dies," said Seoul Semiconductor CEO Jung Hoon Lee. "The P4 is the only LED product in the world with 240 lumens via a single die."

Seoul says that the high luminosity was reached through its proprietary phosphor and packaging techniques, and it would appear that further improvements are in the pipeline:

According to the company’s statement, we can look forward to seeing a 135 lm/W source next year, and more incremental improvements are expected to lead to 145 lm/W performance early in 2008.

To put the lm/W figure in context, a typical fluorescent lamp operates at 70 lm/W, while traditional incandescent bulbs deliver 15 lm/W.

In October this year, Cree revealed its brightest commercial product - a 160 lm white LED XLamp, which is said to operate with 85 lm/W efficacy at 350 mA drive current.

Meanwhile, researchers at Nichia’s laboratories recently published a paper in the Japanese Journal of Applied Physics detailing a high-power white LED capable of producing 402 lumens at 2 A, and a luminous efficacy of just over 90 lm/W at 350 mA.
 
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Stephen7372 said:
http://compoundsemiconductor.net/articles/news/10/12/3/1

http://www.zled.com/_homepage/home_eng/asp/news_content.asp?news_idx=31

Seoul's single-die source packs 240 lumen punch

5 December 2006

A Korean LED maker claims to have launched the world's brightest single-die white LED light source.

Seoul Semiconductor says that its latest LED technology has resulted in a single-die white source that can emit up to 100 lumens per Watt. Importantly, Seoul is claiming the high efficacy figure for chips that operate at the 350 mA drive current that is required for general illumination applications.


The new "P4" emitter is claimed to produce 240 lumens at its maximum drive current. Two types of commercial device are available – one operates at a typical efficacy of 100 lm/W at 350 mA, and the other is rated at 80 lm/W.

"Conventional LEDs have been known to emit more than 100 lumens with several dies," said Seoul Semiconductor CEO Jung Hoon Lee. "The P4 is the only LED product in the world with 240 lumens via a single die."

Seoul says that the high luminosity was reached through its proprietary phosphor and packaging techniques, and it would appear that further improvements are in the pipeline:

According to the company’s statement, we can look forward to seeing a 135 lm/W source next year, and more incremental improvements are expected to lead to 145 lm/W performance early in 2008.

To put the lm/W figure in context, a typical fluorescent lamp operates at 70 lm/W, while traditional incandescent bulbs deliver 15 lm/W.

In October this year, Cree revealed its brightest commercial product - a 160 lm white LED XLamp, which is said to operate with 85 lm/W efficacy at 350 mA drive current.

Meanwhile, researchers at Nichia’s laboratories recently published a paper in the Japanese Journal of Applied Physics detailing a high-power white LED capable of producing 402 lumens at 2 A, and a luminous efficacy of just over 90 lm/W at 350 mA.
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cool, nice find :) guess we'll just have to wait a lil while for them to be made properly
 
Cree make a 150lm/watt lamp wow!

:D http://www.nichia.com/about_nichia/2006/2006_122001.html :eek: :eek:

White LEDs made from the combination of blue LED and phosphor introduced by Nichia in 1996 enabled LEDs to be developed as the highest efficacy light source.

By the Lamp type LED, (Ex.: NSPWR70), the efficacy was achieved at 150lm/W (luminous flux; 9.4lm) by the color temperature; 4,600K at the If=20mA driving condition. The luminous efficiency of this white LED corresponds to 1.7 times of three wavelength fluorescent lamps (90lm/W), 11.5 times of an incandescent lamp (13lm/W) and even better than high pressure sodium lamp (132lm/W), regarded as the best possible efficacy light source in the conventional market.

Even though it has not been so long since LEDs were introduced for the alternative light source, by using LED technologies enable to largely reduce consumption of electricity and maintenance cost. Nichia put more effort on research and development in LED light source, a safe and easy-to-use light source, to contribute society, as a LED manufacturing corporate social responsibility.
 
Cree's LED's certainly are good. :D 1 hour runtime, 135 lumen, £35 :eek:

fenixp1d03.jpg
 
saitrix said:
Cree's LED's certainly are good. :D 1 hour runtime, 135 lumen, £35 :eek:

fenixp1d03.jpg
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Nice! I'm guessing you got the CE (cree edition)... how is it?

I've got the L1T with CR123 body myself and it's lovely... I'm really tempted to get the P1D CE once christmas is over and done with. Did you get your's from the UK, as I've only seen Fenix's overseas. :)

I also forgot to mention, these CREE LED's are now beating tubes as far as efficiency goes. :D

EDIT: Most of these manufacturers (nichia, souel) are claiming sky high efficiency... Most of them are only getting this efficiency with 20ma. The CREE XR-E is where it's at for a good few months at least.
 
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MikeHunt79 said:
Fluorescent tubes are more efficient than HID lights and LEDs right now. This is why they are used so much.
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you must be jesting

a typical 65watt flory fitting consumes 130 watts due to choke losses and heating in the inductor just feel the choke ( after the fitting is turned OFF )

a 85 watter the last time i checked used 1.6 amps :eek: :eek:
 
lordedmond said:
you must be jesting

a typical 65watt flory fitting consumes 130 watts due to choke losses and heating in the inductor just feel the choke ( after the fitting is turned OFF )

a 85 watter the last time i checked used 1.6 amps :eek: :eek:
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Well I only going by bulb efficiencies... I didn't factor in the choke. LED's also require a PSU which are not 100% efficient (tho 90%+ has been achieved), but you can directly drive them from a battery if you know what you are doing. :)

I didn't know Tubes had such inefficient chokes tbh, surely this is another reason to go to LED.

I still think there is some way to go with LEDs before we see them in house lighting, at the moment the only way to get lots of lumens from an LED is to use lots of them which can turn out to be quite expensive. They do last a very very long time tho, and are very also very robust. :)
 
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Your breakers shouldn't trip when a light bulb blows!

What if somebody is electrocuted via the lighting circuit at night?

They would be lying in a heap on the floor and you wouldn't even be able to see them!
 
Massive Attack said:
my uncle has done his hole house with these bulbs and new fittings hees an electrician and after a few hours of use the LEDs started to pop and die in all the bulbs, bad move imo
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Bad bulbs then. I've used 3 different makes of gu10 led bulbs and never had any of them die.
As i say because of the money invested in fluorescent the big bulb companies haven't taken much interest in leds, so you're left with smaller companies in china with dubious quality.
If he was using custom fittings could it be that he was using a low voltage system and was using the wrong voltage?
Leds only 'pop' if overvolted or damaged i think. They normally die by getting dimmer, either due to old age or slight overvoltage. They must have been either bad leds or heavily overvolted to 'pop'.
Tesla said:
Your breakers shouldn't trip when a light bulb blows!

What if somebody is electrocuted via the lighting circuit at night?

They would be lying in a heap on the floor and you wouldn't even be able to see them!
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Initially all gu10 halogen bulbs could trip a breaker if they blew, and i think about 25% of the time they fail short circuit. I still can't believe they were allowed on sale, one of mine blew my dimmer switch.

Thankfully most makes now include a built in fuse but its still not ideal.
 
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