FalconWireless Tech Support - KF4HAZ wrote:
>
> Hey Roman hows the high voltage version coming?
> I am in need of a smps that can take 200 - 300 DC volts input and deliver
> ~13.6Vdc out at 10 amps
>
> Lonnie - KF4HAZ -


Ha ha! :o) Hi Lonnie, so you want me to convert my
tiny cheap 2-transistor regulator to 300v input and
total 140 watts! Wow!

There are *many* issues, probably the worst being that
13.6v @ 10A sounds like the needs of ham radio equipment,
and you will require ISOLATED output that is NOT at
mains potential!! My circuit is totally UNSAFE for
mains "off line" use, as it has no isolation of input
and output. This is illegal for any PSU that may be
touched by the end user and run from the AC mains.

As far as technical issues go, both Russell and Alexandre
have built high voltage 2-tran circuits and tackled many
of the tech issues... One being that the buck diode must
be rated for high voltage, and hence will be inefficient.
Then the buck inefficiencies from the very short pulse
duration 340vdc -> 13.6vdc (about a 4% width pulse), then
the problems with transistors communicating over a 340v
drop, etc etc.

You need an "off line" SMPS converter, with a transformer
so it can use low voltage schottky output diodes, and
MUCH better feedback with optocoupler etc.
These are common and cheap now, i suggest trying;

http://www.jaycar.com.au

who have item MP-3110 which is a 240vac -> 12vdc 150W
SMPS supply for $109 AUD (about $60 USD). They are on
special this month.

You can change the 12vdc output to 13.6vdc output by
changing one zener diode next to the optocoupler.
:o)
-Roman

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.