[sdiy] Voltage amplification via op amps

[Scott Bernardi]

Couldn't you just use a regular non inverting amplifier with the trimpot
in the feedback loop?  This would give an adjustment range from unity
(Rtrim adjusted to 0) to 1+Rtrim/R. Pick R = max(Rtim) and the top of
the amplification is x2.

Peter Grenader wrote:

> Kids,
>
> anyone have a quick and dirty circuit for (almost) doubling a voltage
> control input which also allows for some sort of trim pot adjustment?  I
> assume an op amp with 2 to 1, but I was hoping someone has worked this out
> already so I could...ah...'borrow' it?
>
> Let me be a little clearer:
>
> I've got a VC input, works great. Now I want to amplify it's range, but will
> need an adjustment (trim pot) to assure the adjusted range is exactly what I
> need (you see, 'doubled' above was a bit of a generalization).
>
> I can't change the range on the input voltage, that needs to stay where it
> is - I need to increase it after it arrives into the circuit it's
> controlling.  I also undersatand that I'm dealing with the limitation of the
> supply voltages to the op amp itself, but I think the max level of the input
> vc will allow me this headroom without problems.
>
> i hope.
>
>
>
>
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