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Old September 18th 09, 05:53 PM posted to rec.radio.amateur.homebrew
brian whatcott brian whatcott is offline
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First recorded activity by RadioBanter: Jul 2009
Posts: 48
Default Power supply transformer advice

Tim Wescott wrote:
.... 1100 watt defunct microwaves can be had for the asking.
They have a particular transformer core design that makes it easy
to saw off the 1 KV secondary, and with the
generous core window, you
could wind 18 to 20 turns of wire good for 10 amps. The turns per volt
is not much over 1 tpv.... And you have a decent rectifier diode for
the spares box too....

Admitted - a bandsaw in the workshop makes a 15 minute job out of this
transformer hack.(if you don't nick the primary)

Brian W
KA5WOG


Brian, I have done this with old uwave transformers, the ones I could
knock out the magnetic shunt with a hammer and punch, but on the newer
ovens the shunt is a weld. Will these still work?

Jimmie

I left the magnetic bypass leg in the core on the one I used for a spot
weld source. Its a security blanket against core saturation due to the
magnetron,I reckon.

Brian W


I _think_ that shunt serves to limit the secondary current and therefore
protect the magnetron.


I agree....

Brian W