The LED: 3 W High Power Blue 445 nm LED DIY Item, NEW - eBay (item 110701310128 end time Jul-13-11 19:04:50 PDT) ($2.20 shipped)

Shipping: The LED shipped the same day I ordered it, but the shipping was not tracked. It came in a plain white envelope, wrapped in saran wrap. I was not a fan of the shipping method, but the LED works.

Voltage and current: The LED wants 3.4-3.8 volts, the voltage of a Lithium Ion or Lithium Polymer cell. It says it wants 620ma, but I think I wants a lot more then that. I started it at 3.7 volts, with no driver, and it worked. I then stepped it up to 5 volts. At 5 volts it is a LOT brighter, but also a lot hotter, it makes that big heat sink assembly hot to the touch in ~3 mins. The my ammeter says it is consuming ~900ma @ 5v.

445nm? I dont own (or have seen) a 445nm laser, but I do own a 405nm, and I have seen a 473nm, and based on other people's pictures, it looks like 445nm. On the distant walls it looks like 405nm, but when aimed at a close wall, it looks like what I imagine 445nm to look like. It will make GITD stuff glow. Its viewing angle is ~160 degrees, it lights up a room's walls and ceiling almost completely when on the floor.

Pics:

On the heat sink

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you should try to find the mfg's spec sheet on it. but if you get it for 3 bucks who cares. but make sure you heat sink it well.

michael.

That was what I thought too. Even if it dosent work t at all, it was $3.

That was my next question. I have a large lab style heatsink, but don't those LEDs have contacts on the back? How should it be heatsinked without shorting the pins?

i'm not sure about yours in particular but other leds where the frame is an electrical path have been case positive like the red phlatlight pt54. i don't know how to test for that though. hope fully somebody else will post.

michael.

That's 3W input. Output is likely ~200mW.

hey, cyp... So when led's show a rating, it is the power consumption?? Or it just depends on the mfg?

michael.

Power ratings for LEDs are 99% of the time Input power. Sometimes, though, when you're talking about dental blue, deeper blues, and UV LEDs, they list output in mW.

According to that link, LED is attached to a star board. You can attach this star board to the heatsink, and the + and - pads on the top side are the connections that go to the LED. Metal star is most likely insulated from the LED and its connections.

Thank you, +rep

Review added

What 5V source are you using?

Based on...?

A 1.5 amp 5v regulated power supply for lasers. I think it wants more then that because the power supply gets abnormally hot.

When I later threw my ammeter on it it said .92 amps