Magnetic recording media including permanent structures of aligned acicular particles have been proposed as a means of identifying and authenticating a medium. A structure which has an improved remanence difference signal is described. A method of making and examining such a structure is described. Arrangements of such media and record/read-out apparatus by which information can be recorded and read-out without interference from the structural remanence differences are described. The use of the ...

Clusters of elongated magnets are aligned in an end-to-end relationship to provide an elongated magnetic element that is insertable into the central cavity of an annular screen. A circulating stream of liquid, such as hydraulic fluid, is drawn through the screen and over the magnets for removal of ferreous particles or other magnetically attracted contaminants. The magnets of each cluster are arranged in a radial pattern around a common longitudinal axis and are retained in place by spacers loca...

A process for producing magnetic elements is disclosed in which magnetic material having a low copper content is utilized and, prior to deposition of copper for acting as a non-magnetic spacer, a layer of isolating material such as nickel is deposited to isolate the copper from the magnetic material so that, after mechanical working of the magnetic material to form an element and the element is annealed to restore its initial magnetic properties, the isolating layer acts to prevent the magnetic ...

Magnetic alloys of the general formula Sm.sub.2 Cu.sub.1.6 Zr.sub.0.16 Fe.sub.3.3 Co.sub.12-x M.sub.x are provided wherein M is Mn or Cr and wherein x is a value greater than zero and less than 2.1.

A magnetic head for tape recorders and the like is manufactured with cores made of alloys of elements such as Al and Fe which have relatively large potential differences. In order to avoid the galvanic effect which may be produced by segregation and impurities in the alloys, a part of the tape sliding surface is made of an element such as Zn which is lower in galvanic potential than elements forming the cores, and that part of the tape sliding surface is made electrically conductive to the cores...

A magnetic flowmeter whose electromagnet is excited by a low-frequency excitation current that is derived from an on-off alternating current whose frequency is higher than that of a commercial power line source, the on-off current being modulated by a low-frequency wave. A reference voltage-detecting transformer is interposed between the excitation coil of the electromagnet and an excitation current source. The primary of the transformer is constituted by a pair of windings wherein the excitatio...

A magnetic structure having a high magnetic bubble mobility which has the property that magnetic bubbles can be transported in it at very high velocities while using comparatively weak driving fields, comprising a substrate having a (110) oriented deposition surface on which a layer of rare earth -- iron garnet with a substitution of Mn.sup.3+ in iron lattice sites has been grown in compression in such a manner that the layer of rare earth-iron garnet has an orthorhombic anisotropy.

A magnetic compass has been devised which is of the type having a pivot point displaced above the plane of the permanent magnets so that the distance of displacement of the pivot point with respect to the center of force will reduce the tilt angle or tipping otherwise caused by changes in latitude when the compass is to be operated in different parts of the world and a spherical needle bearing can be employed at the pivot point as a result of the increased pendular effect achieved by displacing ...

Magnetic separators for cleaning liquid, pasty and dry materials by separating magnetic from non-magnetic substances contained in said materials, wherein means are provided to form a flow-through housing with at least one separation roll arranged therein which magnetically cooperates with an antipole, said separation roll, including a shaft on which it is mounted for rotation, and said antipole are mild iron parts of at least one magnetic system with a closed magnetic circuit.

An excitation system for a magnetic flowmeter provided with a flow tube through which the fluid to be metered is conducted, the tube having a pair of electrodes mounted at diametrically-opposed positions thereon and including an excitation coil to establish a magnetic field in the tube which is normal to the tube's axis and to a transverse axis passing through the electrodes, the fluid intersecting the magnetic field to induce a flow rate signal in said electrodes, the system including a full-wa...