On Fri, 4 Nov 2011, JIMMIE wrote:

I came by what appears to be a power supply module from some old
military gear. It uses a synchronous vibrator unless my analysis of
the circuit it way off. My plan is to build a circuit to replace the
vibrator with a couple of power FETs driven by a 555 osc and a bridge
rectfier to handle rectification of the output. I was wondering if
there were any circuit designs around before I started to reinvent the
wheel. Also what freqency do they use. Seems like I heard 100Hz at one
time but I dont trust my memory on something I learned 40 years ago.
Any help would be much appreciate.

The earliest replacements would have been a couple of power transistors on
a heatsink, with a few resistors and capacitors, relying on the existing
transformer for feedback (and frequency control).

Of course a lot of early power inverters were about the same, save that
they weren't built around a vibrator supply.

Look in forty year old ARRL Handbooks, I'm certain the 1971 edition (the
first I ever saw) has a simple inverter that is on that level.

I'm sure some built fancier ones, but I'm sure many got by with something
pretty simple. SOme small companies that deal in antique radios sell
virbrator replacements.

Michael VE2BVW