Remote Living > Lighting
LED light E27 as a lowpower light source
ghurd:
Their LEDs are not at all bright by their own claims of 250 to 1800mcd.
Even surplus LEDs are almost always over 4000mcds.
The 'standard' Nichia is about 10,000mcds. That is 5.5 to 40 times brighter.
I have a several LED flashlights, most have 4 LEDs at about 100ma per LED (400ma total!), the LEDs burn out fast (often before the first set of batteries are dead), and the light output is LESS than a single good quality LED at 10ma.
(BG Micro has photos of a few that I have tested. The silver one is worse than can be discribed.)
My 2 cents is you get what you pay for. If it seems too good to be true...
G-
hiker:
toss a resitor in there...........
ArjenNetherlands:
you might be right and i didnt see the ledslamps for real yet but they consist of 14 or 18 or 22 led lights at about 12000 mcd drawing a power of about 1.3 watts in total at 22 pcs so i guess its allright.
I have seen pitures that looked nice i just dont know how they adapt it to 220 volts yet but ill get behind it one day
i guess the qualety is allright since the give a 2 year warranty
anyway thx for your reply and have a nice weekend!
ghurd:
Just some thoughts.
My job is 35% LEDs. I didn't try to sell any LED products here. I have nothing to gain from this. I do love LEDs.
Good LEDs are great. For a small amount of light, or light concentrated in a small spot.
For warrenty, if you import them yourself, you have to pay 2-way forien shipping. Not worth it. It is very expensive. My last importation ended up over $11 per pound (about 7 Euros per kg) for 600 pounds. It is also very difficult to return something made in China, back to China... I have heard almost impossible.
Shipping to the USA would be about $50 for 1 bulb. Each way. Best guess.
Also, they claim mcd is only 1200 maximum per LED in their LED section. The lowest is 250mcd. Good LEDs are expensive, and much brighter (8,000 to 10,000 mcd). The only decent LED chip with a mcd over 10,000 have a narrow viewing angle.
For an LED bulb at 220VAC in something at this cost, the regulation is just a resistor. The lowest current comsumption would be 0.020 amps. That is about 4.5 watts. Any decent 5 watt CFL would be about the same current, a little more, but many many times brighter than these LEDs.
Anyone with enough of the math skills, time, and patience should compare mcd and viewing angle, with candella or candle power. CFLs win for an area light. LEDs win for a night light or reading light. Nothing beats good LEDs in a properly designed flashlight.
G-
ghurd:
Also.
White LEDs last about 30-50,000 hours until they reach half brightness, but only if they are driven at a lower current than specified (about 20ma). The phospher degrades, lowering the output. When driven at a higher current the phospher degrades much faster, lowering the output hours exponentially.
And sorry about the spelling. I speak math ;)
G-
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