[sdiy] Small Resistors and slider pots

[Glen]

At 07:23 PM 4/3/01 , The Peasant wrote:

>Somebody needs to design an optical slide pot that tracks your finger position
>and outputs a cv or whatever based on relative motion of that position. 
>Shouldn't
>be all that difficult...

A long, long time ago, I saw an optical potentiometer in a catalog. It was
a linear, or "slider", style of potentiometer. The unit contained two
tapered strips of CdS, or similar photoresistive material. A beam of light
was moved from one end of the sensor to the other to vary the resistance of
the two elements. The elements were inversely arranged such that when one
element had low resistance, the other had high resistance. I've never
actually seen one of these in person, and I think the only time I saw it in
a catalog, it was a "close-out" item, and soon to be discontinued.

Has anyone on the list seen anything like I'm trying to describe?

Later,
Glen