Northbrook Electronic Coil and Transformers Mfrs 2909 Macarthur Blvd Manufacturer and designer of toroidal transformers laminated and ferrite transformers power transformers r-cores inductors toroids and coils for OEM application. Northbrook IL Electronic Coil and Transformers Mfrs Electro Manufacturing www.electroassemblies.com toroidal transformers toroids inductors r-cores laminated ferrite inductor chokes coils RF coils power transformers audio transformers magnetics design current transformer CT transformers isolation impedance matching fly-back step toroidal transformers toroids inductors r-cores laminated ferrite inductor chokes coils RF coils power transformers audio transformers magnetics design current transformer CT transformers isolation impedance matching fly-back step Business Reviews Electro Manufacturing Testimonials