I answered a Yahoo question:
is joule thief fine as grade 12 physics final project?
Additional Details
Is the joule thief circuit appropriate as 12th class final physics project?I have made a joule thief circuit (http://www.youtube.com/watch?v=gTAqGKt64… as 12th class’s final project. Should my high school add this in my transcript for the Universities? Will this look good?
My reply was:
I built a Joule Thief and connected three LEDs in series across the transistor instead of one. The three LEDs were red, green and blue. I aimed them at the same spot, and when mixed together, they gave sort of a whitish color, but it depends on how bright the LEDs are. The idea is to get them at various distances so the color is close to white. This illustrated that the three primary colors mix together to make white. Also, I could put a pencil in the beam of light, and it would block each of the colors. But since the LEDs are separated apart, there were three shadows. Each of the shadows is made up of the remaining two colors. This showed that green and blue mixed together gives Cyan, red and blue mixed together gives magenta, and the remaining color is red and green to make yellow. This would make a great Physics project, and just requires two more LEDs added to the Joule Thief. Hopefully you can aim them at a screen in a dark room and get enough light to let more than a few people see it at once. Get good ultrabright LEDs for the maximum amount of light.