2-14-2007
I have decided the ZCS LTspice circuit works pretty well now.
It regulates by increasing the frequency for more power
output.  I have added a resistor in series with a diode
to give positive current feedback.  The current is sensed
across the resistor in series with the output.  It also
contains a transformer voltage sense winding like in my
ZVS circuits.  The MOSFET switching timing seems to be
enhanced that way.

8-25-2006
I have built a test version of a ZCS (zero current switching)
circuit to charge the
battery on my electric assisted bicycle project.  I wanted
to use the ZVS USMPS topology, but since the secondary side
is also the booster/controller for the electric motor, the
configuration is too far from optimal.  The ZCS USMPS topology
on the primary side is much more forgiving beside being 
simpler.

I also have done the basic circuit in LT spice.  When I am
fairly confident about it being pretty good, I plan to upload
an LTspice rendition of the concept.