[sdiy] Theremin

[Richard Wentk]

At 19:43 03/07/2004 +1000, Paul Perry wrote:
>I did a lot of hacking around with theremin designs,
>and ended up just using an infrared diode to send a
>beam up, whihc is then reflected back by your hand (or whatever)
>and detected by a photodiode.
>(using a modulated beam to exclude noise from fluro lights etc).

'Scuse my dimness, but do you measure distance by calculating reflected 
trip time, or reflected brightness?

If it's the latter, how linear is the reflection function?

>I found this much more stable and simple than any RF scheme.
>The commercial version is my Frostwave SpaceBeam, but it is
>pretty easy to DIY your own.

Yeah, but you don't get that cool 50s retro antenna look. ;-)

Richard