Op Amp 101

[Joe Boucher]

This M.E. is doing a miserable job of learning about Op Amps.  I
understand the fundamentals now of what one is and what it does, I'm not
completely clear what is the goal.

The GM MAP sensor takes a 5 volt reference signal and alters the signal
as the manifold pressure changes. (Right?) Whether absolute vacuum or
atmospheric is 5 volts escapes me and not important to this discussion,
yet.

As mentioned earlier today or yesterday, a family sedan will develop
around 18 mm hg at idle and maybe 20 to 22 mm hg at cruise and then 0 at
full throttle.

My Camaro develops around 10 mm hg on a good day and maybe 18 to 20 at
slower cruise speeds.  It will also  develop much wilder pulsation’s at
idle than a family sedan.  The engine doesn't really smooth out till
about 2250 rpms.  The power band starts around 2750.

The question of the post is: 
Is the purpose of the op amp to filter the wild fluctuations at idle in
the reference signal because of the cam overlap, or is the purpose to
bend the vacuum signal of the wild camshaft to mimic the family sedan
vacuum curve, or both?

I have pulled a Tom Sawyer and hooked on of the avionics engineers here
at work in to helping me if I can determine the parameters of the
design.

By the way, Steve, if this is in one of your books, I'll buy it.  If
it's not in a book why don't you write one and I'll buy that one.  I
perfectly understand this is your proprietary info, and I am willing to
compensate you in some way, if you can figure out how you want to do it,
within reason.  I ain't made of money or I would buy an Edelbrock
system.

Joe Boucher
'70 Camaro  '81 TBI Suburban