[sdiy] A simpler LED/Optocoupler/Vactrol dimmer

[Justin Owen]

One of the links that Andre M was kind enough to post is a very good discussion on messing with the taper of pots:

http://www.elby-designs.com/documents/tailoringpotentionometers.pdf

J

-----Original Message-----
From: Julian [julian at 22host24.com]
Received: 03.04.2008 19:02:43
To: Grant Richter; Justin Owen; harrybissell at wowway.com
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] A simpler LED/Optocoupler/Vactrol dimmer



> Put the LED in the feedback loop of an op-amp. Makes it linear.


Ive been thinking of using vactrols to control some things, and Grant / Harry have just demonstrated how to get a controlled linear 
response, but what about a controlled antilog response, and a controlled log response?

Basically i want to use the same value control pot for every vactrol, and have some varying logarithmically between value a and 
value b, and some varying with a linear response from b to a, some from c to d etc.etc.  I want lots of different resistances and 
'tapers' from the same input.

In truth, i havent really thought about this very far, but its the antilog that seems the problem...


Julian 


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