Hello, welcome to finding out about what I consider the DIY solution to power
supply design. I began the basic USMPS, the first Universal Switch Mode Power
Supply, design c. 8/2002. It has since progressed to the ZVS USMPS. See my non-commercial
group dating back to early 2003.

http://tech.groups.yahoo.com/group/switchmode/

I use one of the many different forms of the USMPS for almost all of my power
supply projects. Versions of it can be used for needs ranging from single
MOSFET voltage buck/boosters to fully isolated fairly high power bridge
circuits.

The advantage of the USMPS approach is that once you learn the basic principle,
it can be modified to do almost anything needed because of its very simple
signal path. For example, the idea of the ZVS USMPS can be used to synchronize
multiple USMPSs. Thus, I am designing a motor controller/battery charger for
an electric bicycle which uses the same transformer for both motor control and
battery charging. It also should be able to use synchronous rectification, all
based on relatively simple ZVS (zero voltage switching) circuitry.

I believe the USMPS technique provides the simplest method available having
the best balance between discrete and integrated circuit (IC) components.

Here is the group's description:

Universal switching power supply. Low, high power switchmode circuitry. Ideas:
Pulse width modulation (PWM), zero voltage switching (ZVS), zero current
switching (ZCS), regulated, unregulated, overload protection, impedance-
derived power limiting, high efficiency, electromagnetic interference (EMI).

Joseph Meisenhelder