Thursday, October 23, 2014

Color LED Disco Light

A quirky ebay find.... designed for dance floors or parties.

The use of a rotating half globe of lenses and a strategic placement of three leds in a triangle enables a very complex light pattern... much more complex looking that one would expect from such a simple setup.

Tuesday, October 21, 2014

Philips B11 LED Candelabra Bulb Teardown

This bulb met an early demise after a lamp tipped over and the base broke off, a perfect opportunity to tear it down.

The light pipe shows lots of engineering!  It's an attractive-enough bulb, but I would expect that bulb like this  would tend towards the LED filaments over time as they look much better. Candelabra bulbs are often used in fixtures where appearance is paramount.




Monday, October 20, 2014

Removing non Re-workable Potting Compounds

Some electronics use potting compounds to protect the electronic components on the circuit board.  Unlike the LED bulbs that I have been tearing down, there is a whole class of potting compounds designed to be non re-workable.

I was reading a forum entry at eevblog.com where someone was wondering how to remove these compounds for reverse engineering purposes.  Suggestions ranged from strong acids to heat.

Since most potting compounds seem to be epoxies there is an attribute called the "glass transition  temperature" seemed like a promising avenue to exploit.. basically these materials turn from strong glass like substances to rubbery if you put enough heat onto them.  

It was an interesting application of material's property to solve a problem.  Lot's of dead ends on this one... a bunch of things I tried were not successful.

I am glad, however, that LED bulbs use different potting materials materials.  Removing these types of epoxies is not pleasant... a full-face respirator with an organic vapor cartridge was required.... and a full-blown lab-grade fume hood with a  scrubber is really required.


Thursday, October 9, 2014

Facto (Rona) LED Light Bulb Teardown

From one of Canada's largest hardware retail chains.  A good example of a house branded bulb and quite representative of a mid-range 2014 offering.

Envelope of the bulb is glass, not plastic.... found that out the hard way :)  .... hack saws and glass don't mix.

The emitter construction is, yet again, different than other bulbs.  It's remarkable the number of implementation that can be found out there.




Sunday, September 14, 2014

Ikea Leadare 1000lm 2014 LED Bulb Review

A more cost competitive bulb from Ikea, however generally outclassed by other vendor's bulbs.  One thing I noticed, however, is that my viewers from Europe often comment that Ikea bulbs are among the best and most cost effective that they can get.  It looks like the american market still receives the lion's share of the most innovate and leading edge products.

It was a great outing for my new microscope.  The adjustable slide-stage is just excellent when trying to study small things like controller dies.


Wednesday, September 10, 2014

Trail Camera and Back Yard Wildlife

This summer, every morning the fountain is knocked over, the lawn chewed up and the pillow to our hammock has gone missing.

As is often the case in this age of super-cheap imaging  an off-the-shelf solution exists:  the trail camera.

It's a neat gadget.... it's been power optimized so it runs for weeks on a single set of batteries and it has a built in motion detector as well as the ability to record in color when there is enough light and in an IR mode when its dark. 

It even comes with an IR filter which snaps open in the dark and closes at night for the best quality of image.

After a few weeks of surveillance we had our critter!


Saturday, September 6, 2014

Philips '100w' led bulb check in: color change

After about a year of service the Philips bulb seemed to be changing color... a bit more pink.

A quick check with my spectrometer and the neatest of free programs: http://publiclab.org/wiki/spectral-workbench seems to confirm this.

The light output is about the same... perhaps a wee bit less, but nothing to note.

At only 2,000 hours of service I don`t think this bulb will be making it to the 25,000 hour mark in 9 years time if this keeps up.