Laminate transformers are mostly used as line frequency, low frequency and low/high voltage step-up, step-down transformers. Two coils are wound over a core such that they are magnetically coupled. The two coils are known as the primary and the secondary. The eddy currents cause energy to be lost from the transformer as they heat up the core - meaning that electrical energy is being wasted as unwanted heat energy. Laminated means 'made up of insulated layers of iron 'glued' together' rather than being in a single solid 'lump'.