Split Pack Class 2 Power Transformers Triad Magnetics Split Pack™ Class 2 Power Transformers are nonconcentrically wound and designed for PC board applications. With primaries and secondaries side-by-side, rather than secondary-on-top-of-primary,the split bobbin winding and low capacitive coupling eliminate costly electrostatic shielding. These class 2 transformers are offered in a dual secondary configuration with either single or dual primaries.