Decay Characteristics of Electromagnet

The decay characteristics following dc magnetization of a solenoid valve were studied, with one pole, a movable iron piece, covered with either chrome plating or foil. The range of chrome plating thicknesses affecting the time constants was extremely small, under 10 μm in these experiments. Two types of behavior were observed depending on the spring force and the excitation current. One characterized by stable separation times and the other by a rapid increasing separation time.