Diffraction Film Box With Changeable LED Source

This was just a test of an idea I had. I long time back I bought an electronic candle from a dollar store, and the body of it was a sheet of plastic diffraction grating with a color-changing LED inside it.

I opened up the body and saved the bottom with the LED for another project. I then cut it along the seam line to make a flat sheet.

The box is a simple construction: It is 4 inches high, 4 inches wide and 2 1/2 inches deep.

The front is a single large piece of the grid, which is hot-glued to the inside of the box. The back has a mounting ring-made of posterboard-glued to the center of the back: Inside it I cut out a square and hot glued a smaller piece of grid inside the box as well. I did this because I had experimented with the grid and discovered that two sections of grid spread out the light best.

The light sources are commercially made LED Tealights, as they are called. One is the flickering yellow LED and the other is a color-changing LED. I made the mounting ring to hold these tealights in place.

These are the results: The first two are of the flickering LED, and the other four are of the color changing LED. In darkness or semi-darkness it looks good.