The toroidal cores can be insulated with a Mylar foil 1 x 70 %, 2 x 2/3, etc or coated with epoxy resin. In some cases we put it in a plastic housing.

 

All insulation materials are according to the UL94 V0 standard.

 

A typical polyester film (Mylar foil) is 50 microns thick and5 or 10 mm wide. The UL file number is E93687.

 

The cores can be coated with Resicoat EL-HLG03R (800702) epoxy resin. The UL file number is E214934.