Abstract: A permanent magnet, direct current torquer for a gyroscope of the two-degree-of-freedom, free-rotor, force-rebalanced type includes a primary magnetic circuit having axially polarized permanent magnets, preferably of the samarium cobalt type, and flux focusing means cooperating therewith for directing the axial flux thereof in a radial direction for reaction with fields of concentric, axially-effective, frame-mounted torquing coils. The focusing means includes secondary annular axially-polarized magnets and a further magnetic circuit to minimize leakage flux. The primary and secondary annular magnets closely surround the rotor axis so that the amount of inertia of the rotor is minimized, desirably improving the sensitivity of the instrument.

Abstract: A toroidal accelerometer including a toroidal shaped housing having first and second oppositely disposed arcuate shaped electrodes and a third electrode which is a common electrode, all three electrodes being partially immersed in an electrolytic fluid and subject to differential wetting in accordance with the angle of tilt about a horizontal axis of rotation or axis of symmetry of the toroid. A fourth electrode positioned between the first and second electrodes, equi-distant from the third electrode is at all times completely immersed in the electrolytic fluid.

Abstract: A brush and slip ring assembly in which specific resilient characteristics are developed in the brushes by forming them in shapes which will allow the brushes to be simultaneously displaced a finite amount with the slip ring assembly in a vibratory environment which would otherwise produce relative sliding motion therebetween. By preventing the relative sliding motion between the brushes and slip ring assembly, the formation of electrically insulating friction polymers on the points of contact between the brushes and slip rings is inhibited.