white's coil black stuff

[Douglas]

What is that black residue/ powder that is all over the bottom half of a White's coil, and what purpose does it serve, just curious.

[Vladimir MInkov]

Re: white's coil black stuff

I think this is a ferrite powder used for shield.

[WM6]

black stuff

Ferrite or graphite?

[Max]

Ferrite or graphite?

There's a patent somewhere that talks about epoxy+graphite... but probably you have just graphite there glued or sprayed on coil housing.

Kind regards,
Max