Laminierkernen

Laminierkernen are magnetic cores composed of thin sheets of electrical steel that are stacked and insulated to form a low-loss path for magnetic flux. Their primary purpose is to guide magnetic flux in alternating magnetic fields while suppressing eddy currents, which would otherwise cause waste heat and reduce efficiency. Laminierkernen are widely used in transformers, inductors, electric motors and generators.

Construction and materials: The core is built from thin laminations punched from silicon electrical steel. Each lamination is coated with a dielectric layer to electrically isolate layers. The laminations are stacked and clamped to form a solid core; interlaminar insulation and proper orientation minimize eddy currents and maximize permeability. Common grades are grain-oriented or non-oriented electrical steel with silicon contents of about 0.5–3.5%. For high-performance cores, amorphous metals or nanocrystalline alloys may be used. Lamination thickness typically ranges from 0.2 to 0.5 millimeters for power transformers.

Design considerations and applications: The lamination thickness, coating and grade depend on operating frequency, flux density and efficiency targets. Laminierkernen are standard in AC devices at mains frequencies and used in reactors and motor/generator cores. At higher frequencies, eddy-current losses rise, leading to ferrites, powder cores or other materials.

History and context: The use of laminated cores developed with the growth of efficient transformers in the early 20th century, enabling significant reductions in core losses compared with solid iron cores.