At 20:03 19/05/97 +0300, Jussi Vainionp wrote:
>Microchip application note AN513 describes a method for ADC.
>I'm not that great at analog electronics, and I don't quite understand the
>schematics. It has this chip that is supposed to be voltage to current
>converter 4066, but according to my data it is a quad bilateral analog
>switch. How could it convert anything?
>
>I'll try to reproduce a part of the schematic here:
>
>[...]
>
>I don't quite understand what those S1 and S2 things are.

Those S1..S4 are the 4066, as you said a quad analog switch. The numbers in
the circles should be the control inputs, and the other two the pins for
signal i/o. U1 seems to be an opamp (of your choice), _not_ the 4066
(despite the number being very close to it...).

If you want to make some experiments with this circuit, I'd be interested
in the results, and willing to help you with the analog part of it :-)