Ola Alexandre,

>     The circuit proposed by Roman Black works beutifully ! I am using a
very
> similar version of it both for 72 volts input and for 24v input and it is
> fast and cheap. It is noisy and regulation is poor but it is a great
option
> for microprocessor circuits that use very little power. If you search the
> archives you will find the mod's I made for making it work with up to 100
> volts input.

    I also have sucess making the Roman's switchers to work, but I need a
"heavier" suply. I'm needing to project a suply for 9V/500mA output from a
20-30V input and another for 5V/500mA from 10-45V. This last one I think
would be harder to make.

    I'm giving up to make an switching regulator with discrete components
and have already asked for samples of some of the National's regulators.
Yesterday I was turning over the pages of "The Art of Electronics" and found
a reference to the 78S40. I was impressed because this book was wrote on
1980 (I have the edition of 1987) and this means this component is on market
a long time and I have never heard of it. It costs relatively cheap (US$0.80
in USA) and I have orderes 25 pieces to make some tests.

    What of Roman's circuits are you using? What changes have you made?

    Regards,

    Brusque

-----------------------------------------------------------------
Edson Brusque                 C.I.Tronics Lighting Designers Ltda
Researcher and Developer               Blumenau  -  SC  -  Brazil
Say NO to HTML mail                          www.citronics.com.br
-----------------------------------------------------------------

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads