broken ferrite core for smps

[sss]

hello

i wanted to use the ferrite core from pc atx power supply for smps and i accidentally broke it
its EI type core and i broke the E part into 2 pieces .
can i still use the core if i'll glue it back?

[ClassD]

E cores come in two pieces, and they are glued together. If you only broke the glue, then there is no problem glueing them back together. If you broke the ferrite then throw it away

[dkemppai]

You can still use the core, if it can be secured together with tape, or glue. (I prefer tape, as glue will add to the some gap to the core)

To easily dissasemble the cores, soak them in acetone for several weeks. It will soften up the varnish, so you can take it apart easily. I usually have 2 or 3 in a jar of acetone at any give time, just so I'll have one when I need it.

-Dan

[sss]

thanks man that really helps !

i hope soaking it in acetone wount damage the core itself

[dkemppai]

Originally posted by sss
i hope soaking it in acetone wount damage the core itself

It may weaken the bobbin, but it won't hurt the core. (the core material is a metal ceramic, so it's pretty resistant to solvents)
I've build about a dozen power supplies with cores salvaged this way. I even have an magazine article accepted for publication, based on a core from an old pc power supply.

FYI, you may want to watch out for any flyback mode cores. A lot of the PC supplies are foreword mode converters, but there may be a flyback supply out there. You can tell by looking at the core carefully, and noting how well the core sections mate together. If there is any air gap over a few 1/1000ths of an inch, it's probably an flyback mode core. You will want to steer clear of this for a car audio amp.

-Dan