[snip]
>Instead of putting the secondaries directly in parallel, feed each into
>a bridge and parallel the bridge outputs. This prevents any risk of
>reverse current flow.
I've seen this trick before in General Electric transmitters. One such
model had a variety of relays which would stack the output voltages in
various combinations to service the various duty cycles.
Using methods similar to the description by Rich (AG6K) on his web page,
combinations of transformer and rectifier assemblies yield multiple
outputs. The GE Supply I mention had hybrid selection(s) of two
transformers in similar form. This was quite the head scratcher to figure
out the first time through.
This old broadcast xmtr would allow you to choose your "duty cycle" and
power level. The lower choices for continuous duty. If memory serves, it
was more for keeping the pair of 4-400's within their limits, rather than
the power supply. Portions of this old AM Broadcast beast are in my store
room. The "label plate" is in a drawer somewhere here in my house. I was
going to mount it on a leather belt-buckle back in the 70's.
The big kicker about the transmitter was it's operating frequency, the
old VHF Low band range.
73's
skip may wv6f
nospam4me@juno.com
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