Russell McMahon wrote...

>My real results AFAIK are say 85% at Vin = 15 and 55% say at Vin = 200 v
for
>a 10 volts out say. at 600 mA.

and Dave said -
/SIX HUNDRED MILLIAMPS??????  Good grief, no wonder our mileages vary!
/
/We've got an "apples and oranges" problem here- in fact, several of
/them.

Hopefully not!

No intent to decieive here - what I did was report on and publish the
version that I had done most playing with.
I am confident that it will scale down well although I have not done good
tests at that sort of power level.I will try to do so in the next few days
and post results here.
My main intention was to encourage publication of various designs and to
show one very low cost control method. I specd it at the level I did as this
is often where the PICLISt queries lie. The 50 volt plus spec eliminates
most available IC's both linear and switchers.

I'll also try and get to trying a simplifed version of the Natsemi circuit
as it gives better control of the zener current and more flexible setting of
Vout.

Results soon ...



        Russell

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