Abstract: A temperature sensing device which utilizes a pair of inductively wound magnetic cores is disclosed. The cores are constructed so that the permeability of one core changes with temperature at a rate which is different from the rate that the permeability of the other core changes, with respect to temperature. A plot of inductance vs. temperature, thus varies so that the curves for the two cores intersect at the temperature which is to be sensed. The cores are connected together in a four-arm inductance bridge network and a null detector is coupled to the bridge network to provide an electrical output signal.

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 thermal switch for automatically opening a circuit when the ambient temperature is increased to a predetermined level. A pair of conductor wires are arranged in side by side fashion with extremities extending in the same direction. A first spring portion is included in at least one of the conductor wires to provide stored energy when the spring is biased into electrical contact with each other. A localized contact region is included in the conductor wire in the region below the first spring portion. A second spring portion is also included in the conductor wire between the first spring and the associated extremity of the wire. The extremities, contact region, and spring regions being encapsulated with a heat fusible material which biases the conductor wires into contact with each other in a preloaded condition. A coating of rigid insulating material, retaining the conductor wires electrically insulated from each other except at the contact region, is provided over the heat fusible material.

Abstract: A contactless potentiometer which has a linear output characteristic is constructed with a pair of elongated, hollow cylindrical tubes which are made of magnetically saturable material and are aligned so that their axes form an angle less than 180.degree., with both of said tubes having at least one conductive wire coupled therewith which is interconnected with the wire that is coupled with the other tube, and a moveable magnet which is formed as a segment of a circle with a pair of straight sides that move adjacent to said tubes so that the total volume of said tubes that is magnetically saturated remains substantially constant while the inductance ratio of the tubes varies.