Split apart ferrite cores of SMPS transformers?

[ben7]

How do you go about splitting the two ferrite 'E' pieces, without breaking one or the other?

I need to make a transformer for an analogue ESR meter, and I have a few small SMPS transformers to harvest the cores from.

[kaboom]

Re: Split apart ferrite cores of SMPS transformers?

Soak it in mineral spirits, laquer thinner, or naptha, in a small container.

I used a combination of mineral spirits and vodka for some cores.

Let them soak for a few hours- nothing will appear to happen at first. After 24 hours, most should come apart. Sometimes, you can remove the tape that covers the finished windings. It'll help whatever solvent soak in better.

Also remove the tape that covers the outside of the cores. This helps penetrate the varnish seal at the edges of the two E's. The middle leg of the "E" naturally takes longer.

-Paul

[ben7]

Re: Split apart ferrite cores of SMPS transformers?

Soak it in mineral spirits, laquer thinner, or naptha, in a small container.

I used a combination of mineral spirits and vodka for some cores.

Let them soak for a few hours- nothing will appear to happen at first. After 24 hours, most should come apart. Sometimes, you can remove the tape that covers the finished windings. It'll help whatever solvent soak in better.

Also remove the tape that covers the outside of the cores. This helps penetrate the varnish seal at the edges of the two E's. The middle leg of the "E" naturally takes longer.

-Paul

Ok, I removed the tape from the ferrite core, and put it in some paint thinner (mineral spirits).

Will see how it works, in a day or two.

[ben7]

Re: Split apart ferrite cores of SMPS transformers?

Woo!

It worked well!

I put two transformers in.

One did get a small crack in the ferrite when taken apart.

The other came out perfect!

That paint thinner smell lingers though