DIY Optical Theremin

This is a pretty simple projet for anyone who has a little bit of electronics experience.  I used a circuit designed by Michael Una, Check out his website where you can look at his schematic and buy premade Beep Its here:


I built mine for about $20 in parts from Radio Shack.  Although the parts could probably be attained cheaper through the internet, I'm impatient and don't like to wait for shipping.  It took only a few hours to assemble.  I laid it all out on a breadboard to ensure it worked right, then started moving the pieces into a permanant enclosure.  Instead of a petri dish, like Michael used, I mounted my beep it inside an empty 25 CD container, that blank discs usally come in, it opens easily for modification or battery changes, and stays locked pretty well too.