[ARC5] Anybody Know Good Regulator Circuit?

[Rich Post]

Hi Wayne,

Have almost exclusively used the LM-317 and Chinese modules with that chip
as long as the minimum voltage doesn't need to go lower than 1.25 .  Good
for 1.5 amps self-limiting for heat or use LM-350 for 3 amps.  For more
current, use pass transistors.  If using the little Asian modules, add a
reverse bias diode from out to in since the modules do not come with one.
I also bolt on a bigger heat sink.  I would have used an LM-317 on this
homebrew PS (link below) but I had lots of 5 volt regulators, essentially
the same circuit but higher minimum voltage.
<https://people.ohio.edu/postr/bapix/HBpowerS.htm>

I suppose you could also copy the Astron circuit using the LM-723.  Here's
a link where I repaired a dead Astron and added a MOSFET for over-voltage
shutoff.
<https://people.ohio.edu/postr/bapix/Astron_VS-35M.htm>

73 de Rich KB8TAD

On Sun, May 15, 2022 at 10:05 AM <releazer at earthlink.net> wrote:

> Some years ago I bought a Tema 0-20VDC power supply on ebay.  The seller
> reported that it seemed to have been modified to produce a steady 25 VDC
> output by a change to a trimpot.  I finally got around to replacing that
> "bad" trimpot but that had no effect.  I then realized that the 25 VDC
> output is simply the unregulated output of the rectifier.  Obviously the
> regulator section had failed, so I replaced the HA17324 op amp, the only
> active component in the regulator board, but that did not fix it.
>
> Lacking any schematics or other troubleshooting info, I think the simplest
> thing is to simply build a new regulator section using a suitable circuit;
> it simply feeds the bases of a bank of power transistors.  Any of y'all
> have a favorite IC for that application?
>
> Thanks!
>
> Wayne
> WB5WSV
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: https://www.qsl.net/donate.html
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20220515/0d656dec/attachment-0001.html>