Wholesale Air Core Coil Hollow Core Inductor: What is hollow core inductor? There's nothing in the center. The coils, the wires are wrapped one by one, the wires are insulated from each other, and when a current flows through the wire, a magnetic field is generated around the coil, and the strength of the magnetic field is proportional to the strength of the current flowing through the coil and the number of turns in the coil. Similarly, in a certain magnetic field, the coil is used to cut the magnetic lines of force, and the same magnetic field can be converted into electricity. Using this principle of magnetoelectric conversion, it can be made into relays, motors, wireless equipment, speakers and other devices. Conductor material can be copper, iron, aluminum, gold, metal components, such as center of coil can be inserted into the metal type magnetic device to enhance its conductive flow generated by the magnetic field, when the coil center was formed when only the plastic frame or frameless air-core coil, hollow coil widely used, in order to adapt to a variety of needs, it is designed for round, square, oval, and various special-shaped shape. Wholesale Air Core Coil website:http://www.transformerinductor.com/air-core-coil/