Suitable inductor for LM2576

[boylesg]

If I was to salvage a toroid core from a PSU or tv circuit board, which ones would be suitable to make an inductor for an LM2576?

 

[Vbase]

Don't use cores near the mains input they are lossy cores used for EMC suppression. Use the ones that have several different windings, they are transformers and they are suitable for SMPS.
You can also use the ones used for DC filtering.

 

[boylesg]

Don't use cores near the mains input they are lossy cores used for EMC suppression. Use the ones that have several different windings, they are transformers and they are suitable for SMPS.
You can also use the ones used for DC filtering.

OK thanks. Those are the ones that feel heavy, without the windings, and look as though they are made of solid iron. But presumably I am mistaken in thinking that it is iron.

Are they also OK for gate drive transformer then?

The ones used for DC filtering....what do they generally look like?

 

[Vbase]

Iron is a good guess, most cores are from rare earth and iron, some are iron powder.
The DC filtering reside normally next to the medium size caps and near the voltage regulators. Most of them are open core but some are toroids.
For gate drive you can use any core because you need very low power with low inductance.
If you use the wrong core you will notice that it gets hot or that you need too many windings to get the right inductance.
I salvage components often, it is nice to win but it is hard work. salvaging cores is hard because they aren't marked.

 

[D.A.(Tony)Stewart]

For a suitable Inductor like 100uH, compare size , R, L and A-s values
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