precision rectifier

[Jim Patchell]

John E Blacet wrote:

> Off the top of my head, the LM3900 solution still requires the 14 pin
> package on the board even though you use only one section. It is also
> not very precision, with some offset present. Used in the KW, this is
> not an issue, but as a general circuit, you might just want to go the
> standard 2 op amp route.
>
> If space is an issue, use a dual. For more space saving, you can put in
> a least one SIP resistor package, using a couple of Rs in *parallel* for
> the R that is typically 50K or so compared to the others  which are
> 100K!
> --
>

    Using a resistor network is a good idea for another reason.  Even
thought the tolerence on these things is only 2%, the resistors are actually
matched pretty good.  Plus, they will track each other.

>
> Regards.
> -------------------------
> John Blacet
> Blacet Research Music Electronics
> http://www.blacet.com
> -------------------------
> blacet at monitor.net
> -------------------------
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    -Jim