Wednesday, December 17, 2014


A light bulb from a local hardware store.  A good example off an 'off' brand.

Sunday, November 30, 2014

16 Foot Long Flashlight

A left-over 5 meter long roll of LED lighting tape from Amazon , a $2 tape measure and some lithium ion batteries.

Sounds like the ideal ingredients to make a room-sized flashlight... useful when the power goes off.

 The spring steel in the tape measure makes it easy to rapidly deploy the light as the steel causes the reel to rotate on it's own.  The  li-on batteries should provide at least a hour's run time and the light is about 1000lm's which is enough to provide emergency lighting to a pretty fair sized room.

Rolls up easily when you are finished with it... this led tape has a protective silicone coating so it should even work out doors.... perhaps a good camping light!

Saturday, November 29, 2014

LED Plant Grow Light

In the seriously neat category is this bulb: it has emitters tuned to two wavelengths that apparently produce the best plant growth and the best flower growth.  400 nm and 600 nm.

It's an interesting application of the ability of LEDs to produce very specific and narrow wavelengths.

A fun science project as I needed to build a box with two separate, but equal sections to house two bulbs.  I used a CREE 40W bulb as a reference as it draws almost the exact same power as this grow light.

There is definitely a difference in the plants ( I grew the fastest growing seed I could find at my local garden shop: curly crest).  The grow light side had thicker stems and the color was a deeper green.

A fun mix of physics (with the spectrometer), woodworking for a case, biology for the knowledge that tuned wavelengths are important, and a bit of electrical engineering thrown in for good measure!

Wednesday, November 19, 2014


A viewer of my you tube channel asked about this power supply which I have had on my bench for a few years.  A short review video.  The 100W rating and up to 60V or up to 5A has proven to be a very useful range (most of my other supplies seem to always fall far short of 60V which had always been a problem).

The build quality was reasonable for the money paid (about $300).

The only knock on this supply is if it goes into current limited mode right after a power cycle... the control loop looks a bit loose and there is some over shoot.  Generally not a problem for the work I use it for as the voltage control on power-cycle is well controlled.

Tuesday, November 11, 2014

CREE 4 Flow LED Light Bulb Tear down and Review: race to the bottom, 2nd entrant

Very similar to the Philips Slim Style.  Appears to be a very cost effective bulb, but that required some compromises.  It will be interesting to see what level of market presentation bulbs like this will get... one can see where there is a place for them in the market.

Better bulbs can be had for not much more money.. however if they get tossed into a utility rebate scheme where they cost only a few $'s each I can see places where they could fit in (seldom used bulbs where light quality and noise performance is not paramount).

Wednesday, October 29, 2014

Openbeam: Rapid Mechanical Prototyping

Over the last few months I have had a few project on the go which required a mechanical aspect. I have been keen on trying out some OpenBeam (  This kit can be easily purchased on Amazon in the States and at in Canada.  The owner of the company writes a persuasive and interesting blog on running a business based on his expertise in mechanical engineering.

However metal fabrication is not an area where I am an expert..  After sifting through lots of Youtube videos, personal web pages and reading a few books I picked up enough knowledge to fabricate what I needed. This video is simply some of the techniques that I learned... perhaps of use for those also considering openbeam.

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.