Testing opamps (was: Re: op-amps, Poly's)

[jhaible]

> I think there was a thread a while back on testing op-amps... the way
> op-amps work isn't really condusive to simple testing with a multimeter.
> You would need to first see a schematic and figure out what the said
> op-amp is doing. Best to bone up on electronics theory. 

I have built a little box with 3 sockets, one for single opamp,
one for dual opamp, and one for quad opamp layout. a handful of resistors
and capacitors form a cheap oscillator with each opamp that's plugged
into any socket (positive feedback for hysteresis, RC negative feedback).
Then there is a capacitr for AC coupling and a LED that glows if the
circuit
oscillates. Very simple, and I've been testing every opamp before using it
over more than ten years.

JH.