[sdiy] Three Leg Photocell Hunt

[Aaron Lanterman]

On Mar 30, 2010, at 3:48 PM, Tim Parkhurst wrote:

> On Tue, Mar 30, 2010 at 12:09 PM, Kyle Stephens <lightburnx at yahoo.com> wrote:
> The trick though, is that to simulate a pot being used as a voltage
> divider, you'll want two photocells with one going up in resistance
> while the other goes down. I can't see how this would work with both
> cells in a single package. You might be able to get the proper
> response by using two photocells, and driving one with an inverted
> copy of the LED control voltage.

For an example of something like this, see the crossfader in the balanced modulator in the Music Easel:

http://rubidium.dyndns.org/~magnus/synths/companies/buchla/Buchla_2080_5_200.jpg

(upper right part of the schematic)

- Aaron