Need the Sticky Details of how the Theremin actually works. Please help!

Hi all. I'm new at theremins, and have decided to use it as the topic for my physics project. I've been browsing the forums, trying to find out exactly how theremins work. For simplicity's sake, I'm going to build an optical theremin. I have the all the materials and the schematic, however I need to know how the thing functions before I go screw it up.

I've tried comprehending what GordonC and others have said in this thread: http://www.thereminworld.com/forum.asp?cmd=p&T=2483&F=3
but so far, I have had little luck.

Could someone help me with this problem, or point me in the direction of some reading material?

Thanks.

An "optical Theremin" is not a Theremin: the whole basis of the design is that it generates the tone by unbalancing one of a pair of variable oscillators through the variable capacitance of its electromagnetic field. If you replace that with an optical sensor, well, you've created a similar-sounding but essentially different instrument.

I assume you didn't realize that, but please keep it in mind so that you understand that when you say "please tell me how a Theremin works so I can build an optical Theremin", you might as well be saying "please tell me what wine tastes like so I can know if I want to try this kool aid." (Non-americans: kool aid is a powdered drink mix marketed for children, sold in a variety of unrealistic fake fruit flavors.)

There are a number of Theremin schematics and designs available on the net that should contain all the "how it works" informaton you could want: you can find several linked from this site I believe. It's also not hard to obtain a copy of Leon Theremin's original patent, for that matter. Or you can just buy a kit.

The "Operating principles" in this wiki article could be a good start.

http://en.wikipedia.org/wiki/Theremin

hope-that-helps
good luck

Thanks for the quick response. I am aware that optical theremins are not technically a musical instrument, but I guess I wasn't quite clear on my question.
I had meant to ask how optical theremins functioned.

I didn't know that I had to be specific to discern between normal and optical theremins each time I mentioned it.

No worries.

Many of us consider a Theremin to be an electronic instrument who's interface consists of two antennas of some sort which control volume and pitch and is played without touching it. Usually a descendent of the original invention of Lev Termin.

The word theremin has subsequently been applied with less care to other space controlled and even tactile instruments.

I hope you will forgive any impression of Puritanism about it, but it does help us keep our discussions clear. Especially when trying to help some one on the forum, as many details as possible about the instrument and the individual's goals can save confusion and wasted time for everyone.

Best of luck with the project! No one I know has built and optical instrument.