Monopoly in Lights

Enriching the Electric Company

The Name is Type… Prototype

Before any serious construction on the board can begin, the basic premise of lighting a translucent rectangle of plastic with an LED needs to be vetted.  So, it was time to go to the workshop and figure out how to best cut tiny pieces of plastic and assemble them into a workable shape.  After a few false starts with the table saw and miter saw, I figured out a few approaches that seemed reasonably safe, and which did not involve flinging plastic cuttings across the garage at high velocity.

Once I had some pieces of approximately the right size prepared, I assembled a prototype test box using that most familiar of all quality construction tools, Scotch tape.  (Did you know Scotch tape was named based on an ethnic slur, saying that someone’s boss was being cheap?  Go look it up somewhere.)  Hey, it did the job.  Hooked up an RGB LED, wired some reasonable colors using different resistors, put the box over it, and… oh dear.  Even using a diffused LED lens, it’s still very obvious that there are three separate color elements under the plastic, and the top of it is lit very differently than the bottom.  Well, this won’t do at all.

After some research, it seems that the best solution to this is to mount the LED to the side of the box, rather than the bottom, then coat the inside of the box with a white material to reflect the light, giving it a much larger space in which to mix.  So, after a visit to the trusty drill press and application of some very expensive typing paper with more Scotch tape, my side fire test was ready.  This time, I had much more pleasing results, with reasonable color mixing and no particular hot spots.  I still needed to keep the LED from being too close to the top of the box, or it would give a hot spot, though, so I can’t make the board as completely thin and streamlined as I had perhaps hoped.  This is still well within the realm of reason, though.

Next step is to actually light the prototype box using an LED powered by the LED driver chip.  Until that test is performed, I can’t be sure that a single LED will be sufficient to light the whole space.  If I need to light two per space, things may get complicated, so let’s hope that’s not a problem.

April 28, 2012 - Posted by | Construction

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