[sdiy] Which opamp pins wiring is best for CV out ?? A or B ??

[David Brown]

If the output resistor is in series with the feedback resistor then 
the output voltage is constant regardless of the load.

With a separate output protection resistor, you will have different 
voltages if the load is 10K, 50K, 100K, etc.

With the protection resistor in series with the feedback loop, there 
are multiple voltage dividers that offset each other.  Think of it 
this way ... the op amp will generate a voltage slightly higher so 
that at the output connection node the voltage will defined by 
-Rf/Ri.  It's compensating for the drop in the series resistor and 
the load. - Dave

At 05:36 PM 2/26/2009, Tom Bugs wrote:
>I think it is a non-inverting opamp buffer
>- signal into non-inverting input
>- there is a resitor from the output pin (100r ? 1k)
>The question seems to be (and I've wondered this too) - does the 
>feedback to the inverting input come before or after the output resitor
>- I've always used the 'pre' method (a) but have seen the 'post' method (b)
>Puzzled me too.