photodiode controller

[Stewart Pye]

Hello Again,

I don't really want to take the theramin approach. Too much hardware. I was
hoping there is an easy way to do it optically and get a good range in
various lighting conditions. Maybe I'll give the circuit I mentioned below
a try.


At 22:30 28/02/99 -0600, J. Larry Hendry wrote:
>Well, certainly you can produce CV from the difference between two RF
>signals as is done in the PAiA Theremax.  In fact, the PAiA has a circuit
>included that produces CV.  I think you could count on about 18" of hand
>movement sensing depending on adjustment, antenna or plate, etc.
>Larry Hendry

>> From: Stewart Pye <stew at uq.net.au>
>> To: synth-diy at mailhost.bpa.nl
>> Subject: photodiode controller
>> Date: Sunday, February 28, 1999 5:59 PM
>> 
>> Hi..
>> 
>> I'm building a controller for CV and midi and thaught I'd try a photo
>diode
>> recieving a 10kz signal being reflected by the hand from an led right
>next
>> to the photodiode. This is then demodulated and filtered as in Elector
>> march 1983 pg55.
>> 
>> Elector says it will measure distance up to 6 or 8 inches. Does anyone
>have
>> a better suggestion for sensing hand movement??? Longer range would be
>> better. I'm using a microcontroller so the transmitter cicuit fom elector
>> can be simplified.