Today I tried a 20W Hong Kong led I found on ebay. It’s a 20 watt model, theoretically capable of putting out 1100 lumens… Unbelievable! One single 10$ led can replace conventional room lighting. See the pics.
Watching closely, it is not a single LED, but twenty individual 1-W chips tied in series and parallel in a single package. The seller also has a 50W model arranged in the same fashion.
These are the parameters of my20W Hong Kong led; there is no official datasheet, even if the page of the seller cites the luxeon brand. The following information however is all I needed to make a quick try:
Lens Color: Water Clear
Emitted Color : Warm White
DC Forward Voltage (VF): 13.5 ~ 15.0 VDC
Forward Current (IF): 1400mA ~ 1800mA
Viewing Angle: 140 Degrees
Color Temperature: 5500K
Intensity Luminous (Iv): 1000LM
After some rough calculations I found that a 18V power supply and a couple of 1 ohm resistors (what I had lying around) was just about right to turn the led on and keeping within spec. The heatsink (coming from an AMD processor box) keeps the led cool, and prevents it from frying up in a few seconds: this little beast puts out a lot of heat.
See for yourself the comparison pictures between a conventional light and the led ligt from the test setup:
As you can see a single led can replace a whole chandelier of six light bulbs, giving comparable results and a clearer light. This is definitely going to be the lighting system of the future, because duration and consumption are far more efficient than conventional systems. I wonder what the 50W model could do.
A final word of recommendation: if you decide to try one of these leds, make sure you don’t watch it directly… it is like when you watch the sun with your bare eyes. Always wear sunglasses when you’re tinkering with these things.