Looking for projects and resources on transformer shielding

[shad]

Transformer shielding

There is some words said about this theme,but nothing to start building from.
I'm looking for cheaper method to shield toroid,like steel(good for shielding)and copper(shielding unknown for me)
So what do you think about steel and copper composite.steel(1.5mm)and copper 0.7mm or more.I have something on my mind and i keep you informed.All very experimental,but who knows.

Any theoretical stuff,or DIY projects are very welcome.

 

[Moss]

No need from steel

Copper works as electromagnetic shield. That is why it is good for HF. Steel can reduce magnetic field from DC curent wich is imposble with copper shield. There is no need from steel shield if you don't have DC in your transformer in my opinion.

 

[shad]

Thanks

Thank you for quick ansver.

 

[mtawab74]

hi
as i know troid needs no shield it's inherantly shield by its troidal shape

 

[shad]

Nothing is perfect

 

[TomAss]

Hi,
right, toroids have a LOWER leakage flux respect to
conventional transformers, but they still have.
I had problems with toroids and i solved them in two ways:
1) wrap the toroid with the same iron foil used to make the core,
a 5mm shield reduced (in my application) the LF interference
of at least 6dB.
2) orientate the transformer (moving it circularly around its
fixing bolt) to minimize the interference.

3) (not listed) if it is difficult to shield the interference "source"
(the transformer), you may try to shield the "receiver" (the
sensible area of your application).

In my opinion, since it is not a ferromagnetic material,
copper is not suited for magnetic field shielding.

Bye everybody.