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Broke ferrite core

Hello;

I was disassembling a small power supply transformer that used one "E"
and one "I" ferrite cores; it needed to be rewinded with new magnet
wire. The manufacture used some kind of epoxy to hold it in place which
required it to be heated up in order for it to melt; after heating it
up, I pulled the "E" core out and it broke into a few pieces.

My question is...could I super glue the pieces back together? Would it
still work properly? This has never happened before, so I don't know
what would happen and I don't want the circuit to fail because of it.
If it doesn't work, where could I find replacement bobbins and ferrite
cores at? I'm repairing a rare hard to find (expensive) laser power
supply. Thanks for the help!
 
J

John Popelish

Jan 1, 1970
0
Hello;

I was disassembling a small power supply transformer that used one "E"
and one "I" ferrite cores; it needed to be rewinded with new magnet
wire. The manufacture used some kind of epoxy to hold it in place which
required it to be heated up in order for it to melt; after heating it
up, I pulled the "E" core out and it broke into a few pieces.

My question is...could I super glue the pieces back together? Would it
still work properly? This has never happened before, so I don't know
what would happen and I don't want the circuit to fail because of it.
If it doesn't work, where could I find replacement bobbins and ferrite
cores at? I'm repairing a rare hard to find (expensive) laser power
supply. Thanks for the help!
The glues cracks will act as core gaps, so they will lower the
inductance per turn squared value of the core. Was there any gape
spacer between the E and I section, when you took the core apart? If
so, you could compensate for the additional gaps by reducing that one.
If, instead, the contact faces between E and I were lapped to a nice
flat polish (rather than being just as fired), then the makers wanted
to keep the effective gap to a minimum, and the new gaps may seriously
increase the magnetizing current. The detriment of the new gaps
depends a lot on the circuit topology. By the way, I hate to use
instant glue on cores, not only because it doesn't give you time to
get the pieces fitted optimally, before it grabs, but because it is
not very heat resistant. Slow cure (higher temperature, harder) epoxy
is better, I think.

What are the dimensions of the core? You might be able to replace it.
 
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