[sdiy] Breadboards

[harrybissell]

Scott Gravenhorst wrote:

> I do not use simulation software principally because in is _NOT_ physical
> electronics and it's quirks can be vexing, even with the best and most
> expensive simulators.  Yes, they can work, but no, not always and when
> they don't it can be frustrating to understand why.  I will even
> speculate that it's possible for a simulator to give a result indicating
> a design works when it will not in a physical circuit due to limitations
> in component simulation parameters (models).  While this may be rare, it
> can happen.

wha ?...     RARE ???

Its not rare at all. Its very common (of course if you don't USE simulation you

wouldn't know HOW common...)

First of all... a LOT of models (especially the 'defaut' models that simulate
quickly)
do not look for obvious dumb mistakes.  Try feeding a 741 opamp a +/-100V
supply and it will probably allow you almost 200Vpk-pk output... minus the
maybe
1.5V off the rail.  Hope you didn't try that.  My simulator was happy to go to
KV
on the supply pins.

Transistors are prefectly matched. So you can design (say...) a discrete OTA
and
the performance will be fantastic.  The trannies will all be at the same
temperature
as well...even if one is conducting uA's and another A's...

I'm not as rabid as Bob Pease (who hates SPICE totally)... but Scott is right
here.
Unless you verify the results in the real world, you will get hurt !

I don't quite agree about the SBB having 'real world' physics problems. Its not
that
the SBB has capacitance, or contact resistance...  but that these are not
always
the same every time.  You can't (like the simulations) count on them.

Many folks hate IC sockets... then why put every component in a socket ???

OK. Its quick and easy, and it might work.  As long as you're not doing rocket
science... enjoy enjoy...  :^P

H^) harry