indoor lighting test with LEDS(pics) + need info on dimmers?

[richie00boy]

>>I wonder whether some good motion sensors well located to turn off lights when no one is there and turn on automatically when people move would be a better energy saver.<<

I live on an island where electricity is quite expensive. Came up with the same solution. The trouble is that at least with the motion sensors they sell at Home Depot, they wear out about as fast as modern light bulbs. Sometimes go on by themselves too.

What kind of bulbs did that happen with? A lot of the newer smaller bulbs are severely de-lifed by very high inrush current when switching on. The solution is to reduce the stress with a soft-start. I changed my light switches for electronic pushbutton dimmers that ramp up the light and they last a lot longer now.

 

[I_Forgot]

If you want higher efficiency, look at using separate red, green and blue LEDs. White LEDs use a short wavelength blue to excite a phosphor that produces the "white" light. A lot of efficiency is lost in the "translation" of the wavelengths. If you mix R, G, and B sources you can get more white light for less power. Of course, you need some sort of controller to adjust the balance of the three sources to get whatever the color temperature of white light you want. Using such a controller also allows you to change the overall color to suit your mood, etc.

I_F

 

[JinMTVT]

If you want higher efficiency, look at using separate red, green and blue LEDs. White LEDs use a short wavelength blue to excite a phosphor that produces the "white" light. A lot of efficiency is lost in the "translation" of the wavelengths. If you mix R, G, and B sources you can get more white light for less power. Of course, you need some sort of controller to adjust the balance of the three sources to get whatever the color temperature of white light you want. Using such a controller also allows you to change the overall color to suit your mood, etc.

I_F

Problem is that the best current RGB LEDS are at 50%CRI ..wich is seriously not recommended for any indoor lighting

There is some mixed with warm white possible,
but then it becomes very difficult to control all of that

what i loved about the acriche is the simplicity ..
no DC, no electronics, just plug and play

i'll try to contact seousemi for explanation on the poor performance that i have get with my tests...

 

[fernando_g]

Two questions for you, JinMTVT:

1) What does the acronym CRI means? I'm not familiar with the term
2) When you calculate 4 watts, is that the power being consumed by the LED itself, or the whole assembly? Which would include the power in the dropping circuit, etc.

Also..... as AndrewT commented: "how do they reduce the voltage from 110/120Vac to the 4V or 5V with current regulation (italics mine) that the LED needs?" The solutions I've seen are far more complicated than a simple resistor. They usually involve some sort of Switch Mode converter

 

[JinMTVT]

i have measured 92V on the leds pinouts ( individually) when directly connected to the 120V

so i'd say that they are using multiple series "diodes"
with are then connected to paralelle reversed for the down side of the AC waves...something like that

but i have no clue of what i am talking about..
so i could be plain wrong! but that is what i understoor
from all the papers


I just tried to light up my bedroom with the 6500K cool white ones, and they seem to do alot better than during my previous tests on the color quality ,
wonder if there is some burn in for LEDs??

i know now from reading around, that those leds
( as most white leds ) are really some specific very efficient blue leds, covered by some special phosphors,
that reacts to the blue waves and emit whitish light,
thus this is where the blue tint comes from..

a thing that Lumileds( phillips now ) as supposdly worked around with their new K2 luxeons, using some
ultra-violet light instead of blue, to activate the phosphors, wich contributes alot less to the "blue"impact in the white light...thus better acurate color temp

I also believe, that one needs alot of time, to adjust to the LED's white light, since it does not contain as much different waves as the light from incan/halogen
wich we are used to seeing.
Much like the frist CFL weren't "tunned" properly and induced some headaches after only a few minutes of exposure

The more i try to watch those leds, the better they feel...

CRI is acronym for Color Rendering Index
wich seems to be based toward comparing light emitting devices to regular 2500-2800K incandescant light
thus incandescant usually score 95-100%
and everything else scores alot lower

i have also read that a new metric is beeing created for measurements of color rendering accuracy, wich is not biased toward incandescent, but sunlight, under wich our eyes are the most efficient
don't know the name though ...should be in use pretty soon

I haven't been contacted by GE Illumination for their Iio whatever white leds yet,
but i have gathered some information ( not sure of accuracy )
they seem to of the same efficiency than the warm white from Acriche
working on regular 3-5V DC
expensive ( 25$USD + )
and supposdly 80-90 CRI
to be seen

i'll now try to acquire some K2 from Lumileds
with very warm colors to see if i can deal with the CRI of 80-85 and the color temp

supposed to be seriously thermal efficient compared to other LED designs!

 

[Gerrit Boers]

I've also been thinking about using LEDs in the home.
Did you have a look at the Lamina Ceramics product range?

What about using LED cans/spots designed for stage use? LED PAR cans are available for about 50 euros and they give you full control (via DMX) over color/intensity. Here's a
video on YouTube showing what a Showtec PAR56 LED can do.

 

[JinMTVT]

good link!

seems good, but i can't find any tech info on the spectra on those lumina.

They are a bit overpriced though, at 10$USD for a 110lm warm white led array...compared to a 130lm garanteed
warm white K2 from luxeon @ 3.95$ on a star alum pcb

i just purchased all that was remaining of the warm white luxeon K2 @ futureelectronics ..too bad no one else carries those
also got some 6500K to compare them with the 120V AC

now considering to use lower DC voltage leds since the price difference VS output would more than pay for the difference in cost, and the lifetime is alot better on those K2 than the Acriche
( min 50K hours @ 70% brightness under 50C continuous use... very probably to get alot more than that if used with a constant on dimmer )



Anyone have seen a good quality dimmer solution for 3-5V LEDS ?

i'd say that a single run ( from a single control switch )
could need anywhere from 5 to 20 leds
( so from 3.5A to ~15A )
still i am very worrried about the blue waves on the K2 color graphs for the warm whites...

only GE seems to have come up with the UV solution
for it not to impar the visual spectrum of the output phosphor colors

 

[JinMTVT]

http://www.physlink.com/News/071403QuantumDotLED.cfm

let's hope they can work that out quickly

perfect white illuminance as it seems...

 

[JinMTVT]

http://www.physlink.com/News/071403QuantumDotLED.cfm

let's hope they can work that out quickly

perfect white illuminance as it seems...