@hlavac - THAT is a neat little applet! I've been playing with it for about an hour now (where'd the time go?).
If it's a fairly accurate simulation, that right there put a bunch of stuff into perspective regarding op-amps, feedback, and so on.
@ptricks - Yep. I used to work in, and later managed, an AFREP shop for the USAF (if you don't know what that means, don't worry about it. kinda obscure program. basically fix broke stuff, no matter what it is). 2M/CCR certified.
In the shop we had all the neat tools; Huntron 2000, 2800S, Protrack 1 with all the trimmings, high bandwidth o'scopes, programmable waveform generators, programmable power supplies, the whole nine yards.
I'm trying to duplicate the functionality of some of those tools here at my personal shop, without duplicating the cost. And obviously I don't need the full gamut of precision (or cost) that the tools back in the shop gave me.
Heck, if I can build a curve tracer that'll give me a good zener chair, I'll be happy.
I want to do it digitally rather than using multi-tap transformers and try to build it all into a box run off a battery pack vs. plugging it into the wall all the time.....using stuff I've already got here in the shop, PICs of various types, some DAC chips, some ADC chips, a few op-amps, an SPI driven LCD, and so on.
I've already built my own version of a "Mondo Probe" that uses an 18F27J13 rather than the old school 16F870, and bunches more functionality with a lot of room left for more code and a bunch of pins left over....well, I had my own version of a "Mondo Probe" until I decided to check a 21volt battery pack that I thought was dead.
And that's my story and I'm sticking to it...