July 29, 2010 Solenoid Coil Solenoid transformers are three-dimensional coils that are important because they can create controlled magnetic fields and be used as electromagnets. The term solenoid, in fact, refers specifically to a magnet designed to produce a uniform magnetic field in a volume of space. Solenoid also refers to a variety of transducer devices that covert energy into linear motion as well as a solenoid valve, which is an integrated device containing an electromagnetic solenoid that actuates either pneumatic valves, hydraulic valves or solenoid switches, all which use an electromechanical solenoid to operate electrical switches. << Back