Patent attributes
Embodiments of the subject invention relate to an electropermanent magnet core (EPM core) having two permanent magnets (or two permanent magnet portions where each portion can have one or more permanent magnets), including a fixed permanent magnet portion and a switching permanent magnet portion, where a switching magnetic field is used to switch the magnetization of the switching permanent magnet portion, but not switch the magnetization of the fixed permanent magnet portion. In this way, the fixed permanent magnet portion has a fixed magnetization, such that the direction of magnetization of the fixed permanent magnet portion remains the same during switching of the magnetization of the switching permanent magnet portion, given the magnitude and duration of the switching magnetic field used to switch the magnetization of the switching permanent magnet portion, and the switching permanent magnet portion has a switching magnetization, such that the direction of magnetization of the switching permanent magnet portion is switched during switching of the magnetization of the switching permanent magnet portion, given the magnitude and duration of the switching magnetic field used to switch the magnetization of the switching permanent magnet portion.