Saturday, January 24, 2015

Bell+Howell "Ultrabulb": reverse engineering and industrial intelligence

This bulb was heavily marketed on late night infomercials.  It's interesting to sort down who actually made this bulb and then to study the board to determine the process engineering.  One can easily visualize the manufacturing plant setup.


Saturday, January 17, 2015

DIY RF PREAMP AND NEAR FIELD PROBE

A few months ago one of my viewers was asking about radiated emissions from LED light bulbs... he was experiencing interference with his garage door opener and some new LED light bulbs.

It was an interesting question, however I did not have all the bits to test such a question.

For this task one needs a spectrum analyzer with a RF pre-amp and a near field probe.  RF pre-amps and probes can easily run into the $1000's.... which is a bit much for me!

A while back I found an off-brand amplifier and I was hoping that it might work... the construction, however, was far from ideal.

After a long and circuitous route I think I have a working probe... with my knowledge gained it would have cost about $10.00 to make (the commercial pre-amp I bought was $70.00.... only to extract a $0.15 part from it and to throw the rest into my junk bin!).

Video below:


Sunday, January 11, 2015

SUPER CHEAP PCB HOLDER: THE BAKU BK-687

The nice thing about ebay is the ability to get obscure tools at dirt cheap prices.

If you have ever tried soldering surface mount components to a circuit board you soon learn that you need to tape or hold the board down somehow to avoid chasing it across the desk.

I was getting tired of trying to use some tape or a heavy tool to hold the board.

A quick ebay search showed this tool. I am finding it most useful.

Look closely at the listings..... some are metal and some, I think, are plastic.  The metal one, I suspect, would be more useful at it has more mass and will not be affected by hot solder, hot air, or misplaced soldering tips!


Wednesday, January 7, 2015

GE energy smart A19 800lm LED Light Bulb

A bulb marketed by GE.... appears to be from a far east vendor.

Single sided circuit board is unusual, no controller IC also unusual.  One of the few LED bulbs that failled on me had a single sided circuit board... a stress fracture occurred in the solder joint.  With no via barrel to provide additional strain relief I wonder if that was a one-off occurrence or if single sided boards are fundamentally less reliable?

Efficacy was less than stellar... I wonder if there is a great loss of light with the 90 degree diffusion ring?


Saturday, January 3, 2015

Seek Thermal Camera: The Rise of Cheap Thermal Imaging

Seek Thermal (thermal.com) recently released an add-on camera for Android and Apple phones.

The Apple version was the 2nd out so it was a bit of a wait from the Oct release of the Android version .... however once I saw them in stock I placed and order and had it at my house in two days.

It's everything I had hoped for.  Thermal imaging has tons of uses.. but until know it's just been too expensive.

The camera is primarily setup for a 10-15 foot focusv it seems: ideal for finding heat-leaks in houses.

 I have ordered a  Zinc Selenide (ZnSe) lens so I can get a macro-mode to work.  This is needed for circuit board design which I am primarily interested.

The resolution is good (much better than the nearest competitor, the Flir One).  This is going to be a useful tool indeed.


Monday, December 29, 2014

2014 Project Review: The Failures

Not every project made it to a video in 2014!

Here are a few of the more notable failures....



Tuesday, December 23, 2014

Electronics Thermal Design: A Handy Gadget, the Smoke Pencil

A handy gadget which generate white smoke. Useful for tracing the air flow around an electronics assembly.  Probably originally designed for the HVAC industry.... available, strangely enough, in the science-toys section of Amazon.