[JMS] Lambda 28

[Bob Sullivan]

Ronnie,

Bob, WØYVA, here ... I did suggest to Don that the LM339 is a good choice. 
It's a "real" comparator rather than an op amp. Hi. If you have a FAX 
number, I'll send you my schematic.

73, Bob
WØYVA
Personal site: http://www.isquare.com/personal_pages/ras-hardware.htm
Millen (mirror) site: http://www.isquare.com/millen/millen-page.htm

At 11:19 PM 8/25/2005, dbuska at wi.rr.com wrote:
>Hi Ronnie,
>
>That article was recently modified to correct errors in the
>schematics.  You are correct the didoe bridge and electrolytic caps are
>drawn wrong for a negative supply.  The new version appears on Bob
>Sullivans mirror site.  If you copy does not show a revision update on
>the first page and on the schematic page it is the older version.
>
>I'm glad you noticed the error before starting the modifications.  Bob
>also mentioned that a better comparator type op amp might be a better
>choice than my 741.  I forget off had what he recommended, something
>like a LM324.
>
>73
>
>Don N9OO
>
>----- Original Message -----
>From: "ronnie.hull" <ronnie.hull at glowbugs.com>
>Date: Thursday, August 25, 2005 5:34 pm
>Subject: [JMS] Lambda 28
>
> > Got my Lambda 28 P/S yesterday and started modifying it today to
> > provide all
> > the low voltages as per Don's mods at his shack.
> >
> > Don I have a question. Looking at your schematic, how are you
> > deriving the
> > negative voltages? Shouldn't you have to switch the leads coming
> > off the
> > Bridge? Coming off the positive end of the bridge, to the positive
> > side of
> > the  22mf cap, will give you +68vdc..   unless I'm reading
> > something wrong
> > there.
> >
> > anyway, I had to order a 1mh choke and a 5vdc relay and should
> > have them on
> > monday, so I can put the hv sense circuit in then. I have a HP 0-
> > 500vdc bench
> > supply I can use to test the hv sensing circuit.
> >
> > Anyway, when I get this done, all that will be lacking is the HV
> > Supply and
> > finishing up the modulator front panel
> >
> > getting closer y'all !!
> >
> > 73's
> >
> > Ronnie
> > ______________________________________________________________
> > James_Millen_Society mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/james_millen_society
> > Help: http://mailman.qth.net/faq.htm
> > Post: mailto:James_Millen_Society at mailman.qth.net
> >
>______________________________________________________________
>James_Millen_Society mailing list
>Home: http://mailman.qth.net/mailman/listinfo/james_millen_society
>Help: http://mailman.qth.net/faq.htm
>Post: mailto:James_Millen_Society at mailman.qth.net