- Jan 1, 1970
Fuxue Jin said:This is a very interesting suggestion.
The transformer is used as (more or less) a normal power transformer to
drive a low dropout regulator. The whole final unit is under a strong
megnetic field. Also a 5000V HIPOT between primary and secondary is
I don't expect much high efficiency out of it, but want to do the best
if there is any solution.
Thanks for the posting!
How fast does the strong magnetic field change? You may get some
unexpected behavior if the surrounding magnetic circuit induces
current in the air core transformer. It may jump out of it's fasteners
or induced high voltages may cause damage to other components in the
I think the torriodal design would help solve the problem; induced
currents in one direction should be cancelled out by induced currents
in the other direction. Oh, unless the ambient field is normal to the
plane of the toroid, then it looks like one big loop.
It will not be easy to wind and get a 5KV rating. A transformer house
may be able to help you with a nice design that will meet the 5KV
rating and save your hands in the process. Proto rates used to be a
few hundred dollars for 2 to five pieces. Get the design worked out
first and then shop the design around and talk to them about what you
are doing. They are usually very knowledgable about designs.
There are products that use piezo electric crystals to transfer power
with very high isolation voltage ratings. They are primarily for
isolation of 20kV and higher. The efficiency is not so good but they
are immune to magnetic effects.