Switchable magnetic device
AssigneeThe Echlin Manufacturing Company
InventorJohn R. Wiegand
Life of this patent
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Abstract
The magnetic switching device which employs what has come to be known as the Wiegand Effect is described in U.S. Pat. No. 3,820,090. What is disclosed herein is an improved switching device made from an alloy of iron, cobalt and vanadium that provides a greater switching effect. An improved or optimized torsional strain routine for fabricating the wire switching device is also disclosed. The improved switching device provides its maximum output pulse when the wire is switched in an asymmetric fashion.
Claims19
A unitary magnetic device having first and second magnetic portions, both of said magnetic portions being capable of retaining net magnetization after being subjected to a magnetic field, the net coercivity of said first portion being substantially greater than the net coercivity of said second portion, said first and second portions having substantially the same chemical alloy composition, said device having a reverse state wherein said first and said second portions have the opposite direction of magnetization and a confluent state wherein said first and said second portions have the same direction of magnetization, said first and second portions being separated solely by a magnetic interface when in said reverse state, said second portion having a coercivity sufficiently great so that when said device is in said confluent state, the magnetization of said first portion is inadequate to switch said device into said reverse state.
A unitary magnetic wire device having shell and core magnetic portions, both of said magnetic portions being capable of retaining net magnetism after being subjected to a magnetic field, the net coercivity of said shell portion being substantially greater than the net coercivity of said core portion, said shell and core portions having substantially the same chemical alloy composition, said device having a reverse state wherein said shell and said core portions have the opposite direction of magnetization and a confluent state wherein said shell and said core portions have the same direction of magnetization, said shell and core portions being separated solely by a magnetic interface when in said reverse state, said core portion having a coercivity sufficiently great so that when said device is in said confluent state, the magnetization of said shell portion in inadequate to switch said device into said reverse state.
A unitary magnetic wire device having a substantially uniform chemical composition comprising:
- an alloy of vanadium, cobalt and iron in amounts to provide, as a result of cyclical torsional cold working and subsequent heat treatment, shell and core magnetic portions, said shell and core portions being capable of retaining net magnetization after being subjected to a magnetic field, the net coercivity of said shell portion being substantially greater than the net coercivity of said core portion, said device having a reverse state wherein said shell and said core portions have the opposite direction of magnetization and a confluent state wherein said shell and said core portions have the same direction of magnetization, said shell and core portions being separated solely by a magnetic interface when in said reverse state, said core portion having a coercivity sufficiently great so that when said device is in said confluent state, the magnetization of said shell portion is inadequate to switch said device into said reverse state, an external field being required to switch said device to said reverse state.
Dependencies are inferred from the claim text.