390 results about "Magnetic switching" patented technology

A magnetic switching device, includes a first electrode, a second electrode, and a nanoparticle having a magnetic moment and being disposed between the first and second electrodes. At least one of the first electrode and the second electrode includes a magnetic material which has a net spin polarization in its conduction band for injecting, into the nanoparticle, an electrical current including a net spin polarization for overcoming the magnetic moment of the nanoparticle upon selection of a predetermined magnitude for the electrical current.

An apparatus includes a pressure housing configured to be coupled to a vacuum source and a diaphragm sealingly coupled to the pressure housing. The diaphragm is configured to move in response to the vacuum source. A magnet is coupled to the diaphragm. A magnetic switch is disposed opposite the magnet and is configured to be actuated by the magnet when the magnet is a predetermined distance from the magnetic switch. The magnetic switch is configured to selectively actuate the vacuum source.

A system and method for detecting the presence of a medicament reservoir within the housing of an infusion pump. A medicament reservoir, affixed to a reservoir cap is removably inserted within the housing of an infusion pump. A magnet is affixed to or embedded in one or both of the reservoir or the reservoir cap. Alternately, the cap or the reservoir can be made of magnetic material. A sensing device embedded or otherwise affixed to the pump housing senses the presence or absence of the magnetic field created by the magnet. The presence of the magnetic field indicates that the reservoir is inserted properly within the housing and the absence of the magnetic field indicates that the reservoir has been at least partially withdrawn from the pump's housing.

A magnetic tunneling junction (MTJ) memory cell for a magnetic random access memory (MRAM) array is formed as a chain of magnetostatically coupled segments. The segments can be circular, elliptical, lozenge shaped or shaped in other geometrical forms. Unlike the isolated cells of typical MTJ designs which exhibit curling of the magnetization at the cell ends and uncompensated pole structures, the present multi-segmented design, with the segments being magnetostatically coupled, undergoes magnetization switching at controlled nucleation sites by the fanning mode. As a result, the multi-segmented cells of the present invention are not subject to variations in switching fields due to shape irregularities and structural defects.

A method to switch a scalable magnetoresistive memory cell including the steps of providing a magnetoresistive memory device (12) having two bits (18) and (20) sandwiched between a word line (14) and a digit line (16) so that current waveforms (104) and (106) can be applied to the word and digit lines at various times to cause a magnetic field flux HW and HD to rotate the effective magnetic moment vectors (86) and (94) of the device (12) by approximately 180°. Each bit includes N ferromagnetic layers (32) and (34, 42) and (44, 60) and (62, 72 and 74) that are anti-ferromagnetically coupled. N can be adjusted to change the magnetic switching volume of the bit. One or both bits may be programmed by adjusting the current in the word and / or digit lines.

Multiple embodiments of the invention are described which include at least two laminated ferromagnetic layers with differing magnetic anisotropy. The independent magnetic layer farther away from the recording head is selected to have a lower magnetic anisotropy to allow magnetic switching of the multiple magnetic layers to occur at approximately the same head write current even though the recording head field is reduced with increased distance from the head. The improved switching yields improved magnetic recording performance. Laminated magnetic media according to the invention can have a single peak in the normalized DC erase noise vs. head write current plot indicating that the magnetic transitions in the non-slave magnetic layers are written at the same head write current. As a result the magnetic pulse width (PW50) is reduced, overwrite (OW) is improved and media signal-to-noise ratio (SoNR) is improved. Alternatively one or both of the laminated ferromagnetic layers can be replaced with an antiferromagnetically (AF) coupled layer structure that has an AFC-master and an AFC-slave layer separated by a spacer layer selected to antiferromagnetically couple the AFC-master and AFC-slave layers.

An array of multi-state, multi-layer magnetic memory devices (10) wherein each memory device comprises a nonmagnetic spacer region (22) and a free magnetic region (24) positioned adjacent to a surface of the nonmagnetic spacer region, the free magnetic region including a plurality of magnetic layers (36,34,38), wherein the magnetic layer (36) in the plurality of magnetic layers positioned adjacent to the surface of the nonmagnetic spacer region has a thickness substantially greater than a thickness of each of the magnetic layers (34,38) subsequently grown thereon wherein the thickness is chosen to improve the magnetic switching variation so that the magnetic switching field for each memory device in the array of memory devices is more uniform.

A magnetic switching element includes a ferromagnetic layer which is substantially pinned in magnetization in one direction; and a magnetic semiconductor layer provided within a range where a magnetic field from the ferromagnetic layer reaches, where the magnetic semiconductor layer changes its state from a paramagnetic state to a ferromagnetic state by applying a voltage thereto, and a magnetization corresponding to the magnetization of the ferromagnetic layer is induced in the magnetic semiconductor layer by applying a voltage to the magnetic semiconductor layer.

A magnet switch which may be employed in automotive engine starters is provided. The magnet switch includes a stationary magnetic core made up of a disc assembly and a core body. The disc assembly is made of a stack of annular plate members superposed on each other. Each of the plate members has an opening through which a terminal lead of a magnetic coil extends. The core body has a boss with an edge which is plastically deformed outwardly in the radius direction thereof or staked to create an elastic nip which retains the stack of the plate members firmly on the core body. This structure ensures the joint between the disc assembly and the core body to withstand mechanical impact exerted on the magnetic core and stability in operation of the magnet switch without increasing a total production cost of the magnetic switch.

A magnetically actuated reciprocating motor utilizes the stored energy of rare earth magnets and an electromagnetic field provided by a solenoid to reciprocally drive a solenoid assembly. A converting mechanism, such as a connecting rod and crankshaft, converts the reciprocating motion of the solenoid assembly to power a work object. The solenoid assembly comprises a solenoid having a nonferromagnetic spool with a tubular center section and a coil of wire wrapped around the center section. A magnetic actuator has a permanent magnet at each end of an elongated shaft that is received through the center section of the spool. A switching mechanism switches magnetic polarity at the ends of the solenoid so the solenoid assembly is alternatively repelled and attracted by the permanent magnets. A controlling mechanism interconnecting an output shaft and the switching mechanism provides the timing to switch the polarity of the solenoid and reciprocate the solenoid assembly.