Modular Synth Panels

I'm no expert, but isn't that an inverting voltage follower, not a  
comparator? I thought comparators have either no feedback, or a tiny  
amount (hysteresis).

-Chris

On Mar 1, 2008, at 2:18 PM, Mark wrote:

> On 3/1/08, Grant Richter put forth:
> > > Also, I took a look at the schematic. According to the above
> > > website, this module uses 0 - 10V, and I wanted to see how  
> easily it
> > > could be adapted to the -5V/+5V that MOTM generally uses. It looks
> > > like all the op-amp outputs are wired as comparators (ie. with
> > > positive feedback). If that is a mistake, perhaps it should be
> > > corrected.
> >
> >Orcad library op-amp symbols have the minus input on the bottom, and
> >the positive input on the top, don't ask me why. Don't assume
> >op-amp symbols are always drawn with the negative input on top, it
> >has become conventional recently, but different schematic software
> >may not follow that convention, and there are no regulatory bodies.
>
> These are drawn according to that convention, with the negative input
> on top. It's labeled with a "-" and the number 2 (which is an
> inverting input on a TL072). The feedback goes from the output
> (labeled 1, which is an output pin on a TL072), along the bottom, to
> a an input labeled with a "+" and the number 3 (which is a
> non-inverting input on a TL072). So I don't think I'm assuming
> anything in suggesting that if it isn't meant to be a comparator,
> then perhaps the schematic should be corrected.
>
> http://diy.czmok.de/mod/gbuy/wogglebug-schem.pdf
>
>