LED Resource : LED Lighting : LED Light Bulb : LEDs : LED Supply
One of the best resources I've found online for technical information about LEDs. The cheap
junk from China
is simply cheap
junk. In order to appreciate that you either need to learn up about the technical side of LEDs, or appreciate the maxim "You get what you pay for".
Prime suppliers like CreeX and LumiLed often make "the same" white LED but due to manufacturing variations, that "one" LED is then sorted out into ten bin groups for sales. (The brighter "white" processes simply aren't as uniform as the older colors are.) If you just buy surplus, you get stuff from all ten bins. Typically, there may be four or five distinct color groups among the bins, and in each group the brightness may range twofold, so "the same" LED from bin #1 may only be 1/4 as bright as the one from bin #8. That means the cheap LEDs and lamps will have a lot of variation in how birght they are, and what color they are from batch to batch. For some folks that doesn't matter, they're cheap light and that's enough.
Then there's power control. You'll see spec sheets
from that reference page. The LIFETIME expectancy of an LED depends on how much power you run through it, and what temperature it is running at. In a proper design with prime parts
, you can expect over 50,000 hours before the LED is down to 70% of the original brightness. Cheap stuff that's been running on too much power to brighten it up? Way less than that.
Beam spread? Some LEDs have a wide 180-degree beam spread, which may be measured and marked as falling off 50% at the edge of the beam. Others are designed for a 10 or 20 degree beam. The "brightness" is the same--if you're in the beam.
Power control? Some generate RFI, others don't. Some use control modules, which sip at power, while others use cheap resistors, which are less effective and several times more power hungry. Resistors leave the LED running all the time, but PWM power controls may actually be pulsing the LED too fast for the eye to see--and literally leaving it "off" half the time, for half the power consumption
There's a lot more to LEDs than meets the eye, and there's good reason why a single
prime high-power white CreeX LED can cost you ten or fifteen bucks, versus a Chinese POS that costs two bucks--complete in a nightlight assembly blisterpacked two up.
There's some overpriced stuff sold to yachties, but NONE of the prime stuff can be sold really cheap, it simply costs too much to manufacture.
Just like boats, they're all the same, right?