Abstract: A contactless magnetic switch is provided by utilizing at least one pair of hollow elongated tubular magnetic sensing elements which are each threaded with at least one sense wire and a movable permanent magnet which is positioned adjacent and over the sensing elements. The magnet has two straight edges which in a nominal zero position of the switch extend along the longitudinal axes of the sensing elements, preferably for a distance which is slightly longer than their lengths. The magnet is carried in a revolvable or otherwise movable carrier. If the carrier is revolvable, the magnet may be shaped as part of a circular disc and the two tubes may have their longitudinal axes disposed at an angle relative to each other so that when the permanent magnet is rotated in one direction from the initial zero position, one of the sensing elements will lie completely under the magnet while the other will be removed from the magnet and not affected by it.

Abstract: Sensors, or transducers, which utilize elongated magnetically saturable tubes with sense lines that run through the tubes for simultaneous sensing of a plurality of parameters are disclosed. One version involves a single sensing element which has a first pair of diametrically disposed magnetic poles responsive to one condition that is positioned adjacent to one end of the tube and a second pair of diametrically disposed magnets responsive to another condition that is positioned adjacent to the other end of the tube. Another version involves two elements which have temperature vs. inductance characteristics which intersect, and a pair of diametrically disposed magnets responsive to another condition positioned adjacent the two elements.

Abstract: Sensors, or transducers, which utilize elongated magnetically saturable tubes with sense lines that run through the tubes for simultaneous sensing of a plurality of parameters are disclosed. One version involves a single sensing element which has a first pair of diametrically disposed magnetic poles responsive to one condition that is positioned adjacent to one end of the tube and a second pair of diametrically disposed magnets responsive to another condition that is positioned adjacent to the other end of the tube. Another version involves two elements which have temperature vs. inductance characteristics which intersect, and a pair of diametrically disposed magnets responsive to another condition positioned adjacent the two elements.

Abstract: A positional transducer is disclosed which utilizes an elongated, hollow element of a magnetically saturable material which has at least one elongated, cylindrical passageway running through it. Two, or alternately, four, sense wires are associated with the device and are interconnected so as to form a sensing circuit, such as an inductance bridge network, for example. A pair of elongated, generally rectangular-shaped magnets of opposite polarities are positioned adjacent the exterior surface of the magnetic element at diametrically opposite locations. The position of the magnets, with respect to the magnetic element, determines the amount of magnetic saturation of the tube and the output indication from the sensing circuit.

Abstract: Temperature sensors utilizing either one pair or two pair of inductive magnetic elements are disclosed. The inductive elements of each pair are constructed of different magnetic materials so that the permeability of the two elements change at different rates with respect to temperature. A plot of inductance vs. temperature for the two elements, thus, provides curves which intersect at the temperature which is to be sensed. Permanent magnets are positioned adjacent the temperature sensing elements in order to provide a mechanism for adjusting the cross-over temperature point of the magnetic elements.