A month ago Newegg sold the 40W-equivilant Collection LED for $5 each.  This was the first time I saw LED bulbs going for almost as little as CFLs, so I picked up a few.  Not having bought LED bulbs before I did what any normal person would: I tore it apart!


User Performance:

I was able to keep the dissecting tools at bay for just long enough to test the normal user experience.  I wasn't demanding much from a discounted entry level unit; inexpensive lighting was really all I was after.  As expected, incandescent bulbs clearly won't be replaced by this model.  The color made the room look even more pale and flat than the cheap CFL that I was using previously.  On top of that, the ~1 second turn-on delay is easily noticeable, if not obnoxious.  However I've happily placed them in my front porch light fixtures where I use significant energy and I don't care about color quality or delay.  Going from two 40W bulbs to two 6W bulbs running for an average of 10 hours per night will save 680Whrs/day.  Over a year, that's 248kWh, or $30 saved at $0.12 per kWh.  Not too bad!


The plastic hemisphere that passes light can be popped off with a small flathead screwdriver, which exposes the string of 12 LEDs that are connected in series on an Al-clad PCB.



By removing the screw in the middle of the board, cutting the glue holding the PCB to the housing, and desoldering the two leads, the LED board can be lifted off.



This image shows the LED board flipped over on the left, and another metallic disk underneath, likely used to help carry heat away from the LED board, as evidenced by the thermal grease used between the two.



The heatsink disk can be removed after slicing through more glue, exposing the plastic electronics enclosure.  The plastic enclosure is easily removed by unscrewing two phillips head screws and the electronics can be pulled out thanks to the somewhat long input wires.


With all of the parts exposed, I began looking around at the different parts.  After looking around for a bit, I was able to recognize a few parts and the general topology and whipped up a generalized schematic for the system.  Please note that this is conceptual and leaves out some components and may have some errors.  Note: the main current path is in bold.

LED Blub Schematic 12.20.12.jpg


I was going to identify IC but the only component of interest in this design is U1, the switcher IC.  Unfortunately a search of the part markings 'ACH20B' didn't turn up anything, nor was there a logo to go on.  The search wasn't a total loss though; I did come across this website that catalogs many IC marking logos.



Overall Opinion:

Form, fit, and finish were all decent, and the solder joints all looked good.  I was impressed that the manufacturer added the heatsink under the LED board, even if the thermal grease was used sparingly.  The electronics PCB was not anchored to the unit, which I thought was unusual.  And the use of a plastic enclosure for the electronics PCB makes me wonder how hot it gets in there.  Ultimately, Assuming it gets the rated 20,000 hour lifespan, I would certainly buy it again.  Too bad no electronic product lasts that long in the marketplace!