(S)tripping the Light Fantastic

 
What? Candles or simple regular bulbs?
Simplicity is sooo old-fashioned, don't you know!
Put a plug to this lot, and light up the future!

In past weeks here, an extensive coverage of the political, technical, and other issues around the new Philips bulb that was launched in the USA on "Earth Day", (yes, maybe all those components need good "earthing", for safety... LEDs - like CFLs - have component and environmental concerns, as covered on ceolas.net/#li20ledax).

So, what about a look inside?

The following is from the Earth Led Store, Golden, Colorado USA, who - as a counterbalance to previous critical article references posted here - enthusiastically support the bulb
(as it happens, "original price: $ 59.99, offer $ 49.94, and Philips is offering a $10 rebate when you purchase $30 worth of Philips LED products", so perhaps the sale enthusiasm has some financial justification too, given such taxpayer funded rebate programs ;-) )


They do go on to an interesting dissection of the bulb,
on this web page (there are more images on it).

This is the final production version of the EnduraLED A19 L-Prize off, as you can see it is a streamlined three light chamber design compared to the original L-Prize submission which used four chambers. You will also notice that the remote phosphor caps are much more yellowish when compared to the AmbientLED 12.5 Watt which is shown below for comparison.

So why the shift in color of the phosphor from an orange color to a yellowish tint? Lets open the bulb up to find out:

Removing the phosphor caps reveals the L-Prize bulb actually contains two different looking LEDs. Since the old AmbientLED used royal blue LEDs, could this bulb be mixing colors (Red + Blue LEDs) to achieve its high 92 CRI?

Indeed it does and this also explains the shift in the color of the outside phosphor caps as well.

Digging in deeper, we removed the LED circuit boards and found them to be extremely well built with individual ribbon connectors.
The LED circuit boards are secured to the heatsink with a face plate that ensures a tight bonding to the adhesive thermal interface material.

The heatsink itself is quite high quality and as mentioned before has 3 cavities or chambers where the above LED module assemblies reside.

Deep inside the heatsink resides the main driver board. It is covered in rubber to prevent humming and is very difficult to remove in one piece. We tried unsuccessfully to do so but were still able to remove it fairly intact. Its one of the most elegant drivers we've seen thus far and is primarily built around Cypress Semiconductors CY8CLEDAC03L microcontroller.
The CY8CLED is quite powerful and you can read more about it here at Cypress Semi's Site: http://www.cypress.com/?rID=38553

Other components of note are a main distribution board that exists at the top of the bulb to direct power to each of the main led modules.


Here is pretty much everything spread out on an 8.5 x 11 sheet of paper:

The top right shows some of the capacitors contained inside. All are high quality japanese made rubycon capacitors. Overall, quite an amazing product both inside and out. Easily the best built LED we have seen so far.


If you would like to see a video of the L-Prize in action, check it out below. We hope you enjoyed our first "On The Inside" feature. Stay tuned for our next in the near future.

Comment

Certainly, as mentioned before, the bulb has some attractive qualities,
whatever about the price, specification and prize issues covered before.

But again, as also covered, the point is not that LEDs don't have their advantages, rather that all bulbs, including incandescents do:
There is a massive focus - particularly in the USA - on energy and money saving that may or may not arise from using different bulbs.
Ironically the energy and money saving aspects hardly hold overall, as covered on the "Deception behind Banning Bulbs" rundown.

But even if supposed savings arise, that is of course only part of the issue - arguably, light quality and other usage issues are the main reason for using any light bulb, and houses or apartments have many different conditions calling for different types of lighting.

The above article mentions how the blue and red LED mix allows for a higher CRI (color rendering index) rating of 92.
Incandescents are 100, an optimal rating, but more importantly such engineered improved CRI ratings for LEDs ignores that pure color sources are mixed, so that a true broad light spectrum is not obtained - just a spiky spectrum light output, whether as part of Red-Green-Blue LEDs or, as here, white LEDs, that use phosphorescent coating - which is why photographers and filmakers and indeed those who are sensitive to their light surroundings are unhappy with the supposed CRI ratings.

LEDs have their own spotlight and other advantages.
It is therefore ironic that, like here, "warm incandescent" light quality is chased, rather than own innate LED flexibly altered pure color light output advantages (colors alterable just like RGB red-green-blue light points on TV screens, which of course is indeed often nowadays similar Light-Emitting-Diode technology, and is what OLED type sheet lighting is about).

To (badly) copy incandescent light quality - like with the Philips bulb here, which has a fixed color temperature of 2700, just like an incandescent - is just another part of the irony of banning light sources optimal for such usage requirements.
The above bulb would be better served either by a white daylight balance, at least as an option, or by adding green leds to have the advantage that some LED bulbs have of a modifiable light color output (as color temperature), particularly for the price asked, subsidised or not.