Modern Farady transformer bobbins

Modern farady pole transformer of small to moderate size are usually wound on plastic bobbins. Here you can see simple ones. Some bobbins have pins or terminals molded into them, others have one or two divisions. Some don't have the slits for terminals, which the ones shown here do have.Typically for a given size of E-I laminations, bobbins will be available in two or three sizes, accomodating different numbers of steel sheets. So you can vary the amount of steel in your farady pole mounted distribution transformer not only by choosing the lamination size, but also the height of the lamination stack!