- Published: Tuesday, 28 March 2017
- Written by Jon Chandler
- Hits: 1900
One of the issues to be solved in developing the Wake Turbulence Timers was bezels for the red and yellow 3 digit 7-segment LED displays. The old-school traditional type clamped to the panel and provided long 4-40 threaded rods to support the printed circuit board in the proper position. There are two problems with these - they only have red filters and they are over twenty bucks a piece!
Digi-Key has some bezels by Proud Industries. They bezels snap into a panel cutout but don't provide any means of mounting a printed circuit board. Lenses are available in a range of colors, including red and green. For my yellow displays, they recommended their smoke lenses. These lenses were more appropriate for welding goggles than being in front of LED displays! Proud Industries will make custom colors...for a thousand piece minimum order. I'Ve written an article here on dying the clear lens in dye made for glasses....it's basically boiling the lenses in dye for 15 minutes. It's doable, but not practical on a large scale.
Hack-A-Day touched on an alternative bezel idea. Three 7-segment voltmeters and ammeters are available dirt-cheap on ebay. For 0.86" digits, complete meters in bezels are less than two bucks! Even if you throw out the existing electronics, the cost is less than half the alternative.
The Hack-A-Day article suggested building your own microcontroller controller board to fit the bezel where you need a 3 digit readout. I think the genius solution is to design a circuit with a 3 digit serial or I2C LED driver. This would work perfectly for the Wake Turbulences timers, and for other applications. It looks like many of these display housings are made by the same vendor.