A high-speed chrome permalloy switching core

The fabrication, construction and switching properties of an improved switching core are described. It is composed of electrodeposited Cr Permalloy film. The addition of Cr to electrodeposited NiFe film remarkably simultaneously reduces the eddy current effect, the anisotropy field, and the switching coefficient S
w
, and improves the rectangularity. Thereby, a high-speed low-noise core is obtained. The cores are fabricated by the wrapping and slicing of the film. A typical core has an S
w
of 0.2 μs.Oe, a full-selected output current to half-selected output current ratio of 300 to 1000, and a threshold field of 1.2 Oe.