Let's see coupled inductors phasing inverted. Looks like a flyback to
me. The first one is a two switch forward the next example is a
flyback (two switch).
Congratulation's you've just exhibited your lack of reading and
comprehension.
I'm not above reading other peoples suggestion and or application
notes to find a solution to something. I think they call it research.
The controller choice TOP Switch isn't the best external FET's would
be better. The dual switch is a good solution for getting extra power
from the flyback; any generic PWM controller could be used controlling
a HS driver. If you have any practical experience that says otherwise
chime in.
The reason for my interest is the fact that a ready made transformer
is available for 5 bucks, and it's designed for the output voltage and
power I want.
Wasn't trying to raz you. The dual switch topology is useful, in that
it allows recovery of leakage energy directly to the power rails, if
the correct turns ratio is applied, without extra windings or
elaborate intermediate storage. As leakage energy is one of the prime
goblins of the higher power flyback, this is a keeper, if use of
flyback is carved in stone. You should, of course, investigate the
suitability of the same '5 buck' transformer in the new arrangement,
as use of the dual switch does not change design considerations in the
flyback circuit, if all other inputs and outputs remain the same.
Top-switches are extremely difficult to use anywhere other than the
original application design , as their performance otherwise is
undocumented, uncharacterized and unpredictable. If your application
requires a micropower continuous housekeeper, you might consider using
one for that purpose and deriving from it a dithering clock for the
larger interruptible converter, to assist in EMI control. It could
also serve as an overtemperature protection device, low-power start-up
circuit etc etc etc.
RL
