Abstract: Capacitive angle sensor that changes capacitance as a function of angular rotation by employing a vertical cantilever beam capacitor.

Abstract: A non-contact DC current sensor has a housing in which a pair of cantilevered compliant armatures are mounted. In one embodiment, a single magnet is mounted to a free end of one armature portion, and a nonmagnetic mass of the same moment and weight is mounted at the free end of the other armature to compensate for gravitational forces. Strain gages are mounted adjacent the magnet and the nonmagnetic mass on the pair of armatures. The strain gages are connected in a circuit to generate an output caused by a Lorentz force. The circuit includes provision for static gravity compensation, and in one embodiment l/r compensation.

Abstract: An assembly for protecting a conduit having a core and an axial length, which length is susceptible to being pinched by a structure is disclosed. The conduit includes an insulating coating in surrounding relationship about the core, with the assembly including a semiconductive layer in surrounding relationship about the insulating coating, and a switching layer in surrounding relationship about the semiconductive layer. The semiconductive layer being formed from partially vulcanized ethylene propylene rubber including particles of a conductive element in the form of carbon black, silver, nickel, aluminum or the like. The switching layer is non-conductive in its unstressed state and conductive when pinched such that the switching layer completes a current flow path between the semiconductive layer and either a grounded structure or another conductive layer, which condition may then be detected.

Abstract: A hydrocarbon vapor sensor which is simple and low cost and can easily detect the existence of hydrocarbon vapor. The device is temperature compensated so that a change in resistance due to a change in temperature is avoided and an accurate response is always provided. The sensor can be used in a system in which a number of sensors are provided at various depths to determine whether a leak or a ground spill has occurred.

Abstract: A hydrocarbon vapor sensor which is simple and low cost and can easily detect the existence of hydrocarbon vapor. The device is temperature compensated so that a change in resistance due to a change in temperature is avoided and an arcurate response is always provided. The sensor can be used in a system in which a number of sensors are provided at various depths to determine whether a leak or a ground spill has occurred.

Abstract: An apparatus for detecting excessive chafing of a cable arrangement against an electrically grounded structure includes a layer of semiconductive material positioned in surrounding relation with an elongated member such as an electrical cable, tube or hose. A layer of electrically insulating material surrounds the layer of semiconductive material. A detector circuit is electrically connected with a reference end portion of the semiconductive layer. The detector circuit is operable to detect at least momentary contact between the layer of semiconductive material and an electrically grounded structure due to erosion of the layer of electrically insulating material surrounding the semiconductive layer caused by excessive chafing of the layer of electrically insulating material against the ground structure.

Abstract: A conduit has a core and an axial length susceptible to being pinched and chafed by other structure adjacent the conduit. An inner semiconductive layer extends the length of the conduit susceptible to being pinched and has a reference point adapted to be electrically connected with a detecting circuit for detecting a pinch and/or a computing unit for determining the location of a pinch. A resiliently compressible electrical switching layer, which is nonconducting when not pinched and conducting when pinched, is superposed against the inner semiconductive layer.

Abstract: A test system for comparatively analyzing a complex signal indicative of the operational status of an electronic device to be tested includes means for sampling a signal whose characteristics are indicative of the unknown operational status of the electronic device to produce a comparison data base. The comparison data base is processed to produce comparison transform coefficients. These transform coefficients are compared with a set of reference transform coefficients, representative of a desired operational status of the device, to determine the actual operational status of the device. The sampling means includes a conductive element capacitively coupled to the device and permanently mounted in a fixed spatial relationship with the device.

Abstract: An apparatus for optically detecting electronic circuit malfunctions includes a light transmitting plate member which is adapted to be positioned adjacent to a plurality of individual electronic circuit elements positioned on a printed circuit board. First and second polarizing filters are positioned adjacent to opposing edges of the light transmitting plate. As the individual electronic circuit elements positioned on the circuit board are operated, the nonuniform heating of the light transmitting plate by the circuit elements produces mechanical stresses within the plate. As monochromatic or white light is passed through the pair of polarizing filters and the light transmitting plate, a light/dark striated pattern of light is produced on the surface of the second polarizing filter. By recording the pattern of a properly operating printed circuit board, a reference pattern may be obtained. Subsequent patterns of light are compared to the reference pattern in order to detect differences between patterns.

Abstract: A test system utilizing modulators responsive to signals to be tested positioned between a source of electromagnetic radiation and a sensor with the signal to be tested coupled to the input of the modulators. Preferably the modulators are positioned in optical wave guides with the modulators being electric-field operated devices to prevent any significant loading of the signals to be tested. Disclosed embodiments utilize light as the electromagnetic energy with lithium niobate substrates having titanium diffused therein forming the optical wave guides. Modulators are provided by planar electrodes affixed to the surface of the lithium niobate substrate to change the electric field across the optical waveguide. Coupling is conveniently provided to the wave guides through fiber optic bundles.

Abstract: A test system and method for comparatively analyzing complex signals especially those composed of combinations of pulsed signals related to the operational status of apparatus whose operational status is to be determined, is disclosed. In the preferred embodiment a probe, preferably a capacitive probe, is utilized to sense the electric field generated by electrical apparatus. The output signal of the probe is periodically sampled to generate an array of digital signals. This array is processed using Walsh transformations to generate a reference Walsh transform. A second data base is then generated by similarly sampling the electric field generated by an apparatus whose operational status is to be determined. The second data base is then processed to generate a comparison Walsh transform. The operational status of the apparatus whose operational status is to be determined, is then determined by comparing these Walsh transforms.

Abstract: A spring loaded probe pin for making electrical contact with a printed circuit board in particular, a solder pad, is disclosed. The pin has a contact face of deformable synthetic thermoplastic resin to provide an electrically conductive low resistance area contact.