Monday, March 9, 2015

Philips "Warm Glow" LED Bulb: Tune able Color Temperature

One of the drawbacks of an LED is that it will produce the exact same color (measured in Kelvins) at all brightness levels .... problematic when one desires a warmer, more cozy dimmed light.

This bulb brims with innovation to create that effect.  A very neat bit of engineering!

Sunday, March 8, 2015

LEDs, Temperature, Reliability

So I was looking at a bulb with just a terrible warranty and I was wondering if the design is so fundamentally flawed that the LEDs run too hot for good service life, or if the warranty is just super-short to allow the lowest possible sell price.  I collected a data point to help better understand the issue.

Saturday, February 28, 2015

Philips Slim Style '75w' LED Bulb Teardown

Very similar to the 60W version.  Most of the same draw backs remain... I presume there has been trade off on manufacturing costs versus undesirable features.

Sunday, February 22, 2015


From  Neither CSA nor UL approved.  Bad Chinglish on the box.

What caught my eye, however, is the large finned heat sink.  I was wondering if that would translate into a lower operating temperature.

It seems, however, that although it draws 12W, the same as a old Philips bulb, and claims 1100 lm, 300 more than the philips... it runs rather hotter.  I am also not convinced that it's producing considerably more light than the Philips bulb.

Sunday, February 15, 2015


If one makes their own circuit board the need to drill really small holes is important... normally done with a very small and precise drill press at ~$300.

Lots of ebay vendors, however, are willing to sell a small toy dc motor, collet, and some drill bits.... it's an interesting starting point to building one's own.   The use of a toy motor is both genius (so cheap) and silly (the bearings in such a motor are far from precision... and they are really not designed to take vertical loads).

The natural inclination to use this bit of kit would be to turn to my metal lathe and use the milling adapter to whip up a suitable fixture... however I would assume that if one is in the market for $5.99 "drill press", that would be an unlikely tool to have in the workshop.

I instead approach this using only simpler and more likely available tools.

The use of a copper plumbing pipe and union provided an ok-ish linear slide (even with polishing, however, it's not a smooth as I would like).  The off-center spring also is not quite as good as the spring-around-the-pipe that I planned... however getting spring wire to form my own spring (quite a simple task) was not possible as I could not find any of that wire locally.

Sunday, February 1, 2015

Filament LED: Silicon on Sapphire?

A while back I tore down what is still probably the most innovated LED light bulb I have seen.  Called a "filament LED" the LEDs appear to be arranged in a long series row on a glass like substance.

I did an acid de-cap to remove the phosphor.  The LEDs appear to have been grown on a sapphire backing... makes sense as it would not be economic to place so many individual LED dies on a substrate.

From what I can tell this appears to be Silicon on Sapphire.

Thursday, January 29, 2015

DIY Macro Mode for a Seek Thermal Camera

The Seek thermal camera is a nice bit of kit... however it's lens is fixed and focuses at about 10-15 feet.  Great for home inspection, not so good for electronics circuit board inspection.

A new lens, a selfie stick, and a bit of camera gear I already had results in a stable platform on which to record temperature of very small items indeed.