Bobbin wound electronic transformers are used in a variety of electronic applications. These coils are wound independently of the core. The bobbins are made from a variety of materials such as plastics, phenolic, glass and teflon. Most bobbins are molded or fabricated. It can also use a variety of core materials like laminated or taped wound silicon steel alloys, nickel-iron alloys, cobalt alloys: powdered irons and nickels.