Bob Blick wrote:
> I seriously considered this, but it's been a long time since I bought
> any cds cells except from places like Radio Shack, and I was concerned
> about channel matching.

Jameco sells a variety of CdS cells, and they are probably reasonably close
within a batch.  Still, if you need the same gain between multiple channels=
,
then this probably isn't the best method, or you have to calibrate each
channel.  The latter may not be so bad if driven from something like a PIC
which can easily look up and apply calibration values.  That could also be
used to get around the non-linearity.

I didn't have this issues as I was trying to make a automatically adjusted
volume system with a single channel.  I used the same hack in a oscillator
too, to keep the output voltage constant over the frequency range.  It was
sortof like what Bill Hewlett used a light bulb for.


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