[sdiy] photo resistor as CV source

[Paul Perry]

This is pretty bodgie, but it will work..
use THREE batteries, givibng you a wider range
(hopefully, something like +9 to +27 or so)
then, put another battery in series (reversed) 
so you subtract 9v from the output, which now is 
more like 0 to +18!!!

Kludge? yes.
Works? sure it will.
Those batteries will last a long time (if you disconnect when 
not in use).

I know it is possible to make a fine circuit wiht a LM324
and all.. (or for the pros a LM3900) but, you don't wnt to
build a circuit, right?! Right by me!
paul perry Melbourne Australia