Moodometer

I decided to make a moodometer from the battered medium-sized projection display mentioned here. However, the display was really quite battered. When I opened it up (removed the bulb holder) I found a bunch of sand and the components below.

The lens assembly was held in by melted plastic fusing the lens arrays to the plastic case. I worked at the corners with a knife, and managed to remove the lenses, as shown below.

Separated, the lenses are shown below:

The lenses are held in place by the plastic case with concentrically smaller rectangles

I spent some time cleaning out the display. I sanded the rust off of the metal apertures, painted them with black acrylic enamel and baked on the finish. The second lens array (closer to the screen) had rust stains on the bottom row of lenses. I removed the rust using a soft abrasive – which wasn’t soft enough because I scratched the lenses leaving them cloudy. I looked for plastic polish, and found that one can purchase “headlight lens scratch remover” in any auto store (I never knew that headlight lenses needed to be polished before this). This product is a combination of a very mild abrasive and a wax that fills in scratches. I applied it with a qtip, and it worked quite quite well. The cleaned components are below.

A closeup of the new character transparency is below.

I created a screen by sanding ¼ inch plastic with 180-grit sandpaper. I decided to go old-school with this display by driving it with incandescent lamps (half of the originals were burned out, but I had plenty of spares from some large displays). The lamps are rated at 6.3v, and I happened to have a 6.3v regulated power supply. I drove the displays with a uln2003, whose voltage drop gives me a safe underdriving of the lamps. Below are some of the faces. The rightmost screw is connected to a Quantum Technologies QT1100, so touching it makes the display re-randomize, flip through some faces, finally displaying your “current mood”.