Dale Botkin <dale@BOTKIN.ORG> wrote:
> On Wed, 30 Oct 2002, Jim wrote:
> >    "It throws away voltage regulation, too"
> >
> > I don't think his 'app' is going to care about
> > a percent or three 'sag' in output voltage ... he
> > isn't trying (nor does he need to) regulate
> > within .1% or anything close to it.
>
> If that's all we're talking about, then no, it's really not an issue.

I guess I was a little too subtle. The circuit will flat-out not work,
period. Have you ever breadboarded this configuration?

See page 13 of the following document for the proper circuit. You don't
have to use LM195s as the pass elements, but you will need to ballast the
emitters of ordinary NPN transistors appropriately, and perhaps adjust the
drive level of the PNP. I think that you should be able to feed the
collectors of the NPNs from a separate supply with no problem.

   http://www.national.com/ds/LM/LM117.pdf

-- Dave Tweed

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