[NJARC] Switching supplies

[Harry Klancer]

Ed,

I built a B supply for small portables from a design that I got from
Tony Maher in Australia (I think I showed it to you at the museum)
Tony sent me a design update that lets it autostart rather than connecting
it to the power switch (which is what I did). His original design is on
http://www.portabletubes.co.uk/sitefiles/ausbatt.htm
It uses a small toroid, one chip, a few MOSFETs and some misc.
small parts. For the one that I built, there is a website with artwork
for an Eveready and for an RCA battery box you can print and
stick it inside of.. There's probably artwork available for other
sizes.

If you look at it and are interested, I can send you his updates as well
as my US sources for parts. My little one runs on 4 rechargeable AAs
and seems to run for 10 hours or so on a charge.

You could use the same design with beefed up parts for a larger set
such as a trans-O, or if you don't like that you can buy a pre-built
supply that runs on D cells from a guy who is, I think, in South Jersey
(not that location matters).

                                 Harry K

ps - I haven't had an RFI problem, once I added a few
      appropriate caps to cut down the switching spikes on the MOSFETs.
      Tony says he has not had any noise problems either.



edotte at optonline.net wrote:
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> Hello all,I hope everyone has enjoyed their holiday off. And to all who have served, thank you. And to the men and women who died to give me this day off and enjoy it in the greatest nation on earth, I wish I could thank them.Anyway, I have a question. Does anyone have a neat little schematic for a switching power supply replacement for a battery? I see many "portables" had 90 V or 100V batteries and I figure they may have drawn up to 400 milliamps. I figure most are around a few hundred.milliamps.  Anyway I know  you get the point.  But if anyone has or knows of a switching design that is compact, efficient,   and cost effective and would like to share it I sure would appreciate it.Edward
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