Abstract: An optical fiber is surrounded by a protective cladding of a liquid crystal material and fabricated by passing the optical fiber through a die member which operates to deposit relatively thin individual high-strength layers built up to a desired thickness. In another embodiment, the desired thickness is achieved by surrounding the optical fiber or fibers with a plurality of individual high-strength strands of liquid crystal polymer collectively compressed about the optical fiber(s).

Abstract: An electromagnetic parallel rail launcher with an augmentation winding for post-firing inductive energy recovery. A power supply includes a storage inductor which, in conjunction with the inductance of the augmenting winding, provides the inductive energy storage prior to firing. As the launcher projectile exits, the storage inductor is substantially decoupled from the rail and augmenting winding inductance, so that a high efficiency inductive energy transfer may be accomplished between the rails and augmenting winding.

Abstract: Apparatus which provides an indication of gas leakage from the interior of an electric generator into a closed circuit water-cooling system for the generator's stator coils. The closed circuit water-cooling system includes a water tank for degasification with the closed volume above the water level being occupied by a gas of the same type as the generator interior. Sensors are provided for obtaining indications of pressure, temperature and volume of the gas, and from these indications the number of moles of gas in the tank are calculated in periodic time increments. The gas is maintained within certain pressure limits by the addition or venting of gas, and if an addition or venting has taken place from one calculation to a next, a projected value for the number of moles is calculated after the change, had the change not occurred. The difference between the actual and projected value is then added onto subsequent calculated values to obtain a history of gas leakage.

Abstract: A magnetometer system carried aboard a tethered underwater vehicle for confirming the existence of a buried naval mine which then may be neutralized by an explosive charge dropped by the vehicle. The vehicle carries two or more scaler magnetometers and is operated to obtain vertical and two orthogonal horizontal spatial gradients of the magnetic field above the mine location. The vertical distance to the mine is obtained, and this information, along with the known dip angle of the earth's magnetic field at the location, is utilized in conjunction with the spatial gradients for obtaining three mutually orthogonal components of the magnetic moment of the mine, from which the magnitude of the magnetic moment may be calculated. If the magnitude falls between upper and lower predetermined limits, a positive mine classification signal is provided.

Abstract: An electromagnetic launcher having spaced-apart rails for launching a projectile includes a plurality of stages connected to the rails for supplying makeup current during a projectile launch. Each stage includes an inductive power supply and an electrically conducting loop physically adjacent the rails for a predetermined length and including a conducting switch, such as a controlled rectifier array. As a projectile launching armature enters the loop area, a countercurrent is built up in the loop and at current zero the switch reverts to a non-conducting condition, thereby causing injection of the inductive current into the rails.

Abstract: A transducer array which includes backing and an acoustic window separated by a plurality of elongated parallel rail members having notches in the sidewalls thereof. Notches in adjacent rail members accommodate a stave member which carries a plurality of transducer elements. A stave member may be placed in the notch and slid into position from which it may be easily removed by reversing the process. The design is such that when used with a fairing to provide hydrodynamic shape, the assembly may be free-flooded with the surrounding water medium. In situ replacement of a transducer element may be accomplished by removal of a small section of the fairing and the subsequent removal of one or more stave members.

Abstract: A connect/disconnect switch which is partially immersed in a cryogenic coolant includes colinearly arranged electrically conducting hollow cylinders separated by an electrically insulating as well as thermally insulating support member. An electrically conducting plug member is moveable within the cylinders with the cylinders being electrically connected to bus bars. During current flow operation, an electrical path is established between the hollow cylinders by means of the moveable plug whereas when a disconnect is desired, the moveable plug is removed from contacts with at least one of the cylinders thereby breaking the electrical as well as thermal path.

Abstract: A DC power supply which generates little or no harmonics on the supply line includes a bridge circuit having high frequency controlled unilateral switching devices in the four legs thereof and a high frequency filter capacitor connected across two opposed junction points of the bridge to which is also connected a source of input power. The other two opposed junction points of the bridge are connected to a DC loop circuit which in one embodiment maintains a constant current through a load device connected in the loop and in another embodiment maintains a constant voltage. In the constant current embodiment a storage inductor is provided and energy is transferred to and from the storage inductor in accordance with the high frequency switching of the unilateral switch devices. The on and off times of the switch devices are governed by a control circuit which measures the current in the DC loop and compares it with a desired value.

Abstract: A safety switch for use in an inductively driven electromagnetic launcher system includes three tubular conductors each having a substantially cylindrical internal surface, wherein these internal surfaces have substantially the same internal diameter and are positioned at spaced locations along a common axis. A fourth tubular conductor having a cylindrical external surface with a diameter which is substantially equal to the internal diameters of the first three conductors. This fourth conductor is mounted for movement along the common axis such that its external surface is capable of making sliding electrical contact with the internal surfaces of the first three conductors. The external surface of the fourth conductors has sufficient axial length to be capable of making electrical contact with each of the internal surfaces simultaneously.

Abstract: A Tonpilz transducer having head and tail masses with an interposed active transducer section. The transducer unit is positioned within a housing which has a shoulder portion upon which rests a snubber member which extends to a position just behind the head mass. The transducer is supported from the head mass by means of a thin fiberglass tube which extends from the rear of the head mass and engages a flange portion of the snubber member in the vicinity of the housing shoulder. The housing has a waterproof covering as does the head member with the covering of the head member being secured to the covering by means of a removable strap such that the transducer assembly may be disassembled for repair.

Abstract: Apparatus which penetrates a hole through an ice cap from the water beneath the ice cap. A positively buoyant unit containing water under high pressure discharges the water through a nozzle causing erosion of the ice. The nozzle is connected to a telescopic tube arrangement the total length of which is at least equal to the ice thickness so that when penetration is made the tube arrangement can act as an antenna for a surveillance sensor package carried by the unit.

Abstract: TV cable apparatus wherein a stereo module unit at a user location automatically provides for the presentation of an FM audo channel associated with a particular TV channel. The FM frequency allocations associated with the particular TV channels are stored ina computer memory which may be periodically revised. The cable operator periodically sends out the latest TV channel versus FM channel frequency allocation in an FSK coded data signal which is recognized by the stereo module unit which then proceeds with an updating, if required. The data signal is sent on a normally unused FM channel and in one embodiment if this channel is changed, the apparatus is operable to find the new data channel for channel map updating.

Abstract: A diagnostic system for an electrical generator winding which has first and second passages for conduction of cooling gas. The temperature of the gas exiting the passages is determined and converted to a normalized value which may be either high, low or normal. A diagnostic computer determines the existence of predetermined combinations of high, low or normal for the two readings and these predetermined combinations are utilized by the computer which generates respective confidence factors in the existence of certain abnormal generator conditions such as open conductors, broken or blocked cooling gas passages, and sensor malfunctions, by way of example.

Abstract: A steam generator in an electric power generating system is controlled by controlling turbine steam flow with control signals generated by a programmed digital computer system during startup, synchronization and load operation. The digital computer control signals are generated as a function of monitored turbine system conditions and parameters, the digital computer having means for interrupting the normal computing of the control signals when predetermined operating conditions are monitored. Turbine system parameter signals are periodically scanned and operated on so as to condition them for use in generating the control signals.

Abstract: A liquid-filled tube placed next to a generator winding section provides an indication of an abnormal hot spot which may develop along the winding. The tube is filled with a liquid which vaporizes to form a vapor bubble at the hot spot location. Acoustic energy is projected through the liquid in the tube and is normally received at the distal end of the tube. Presence of a vapor bubble blocks the acoustic propagation and forms a reflective surface for the acoustic energy which then is utilized to calculate distance to the vapor bubble. With a known pressure versus temperature relationship, the pressure of the liquid is controlled such that the hot spot temperature may be determined.

Abstract: A cylindrical transducer for use as a low frequency hydrophone and having inner and outer electrodes at least one of which is deposited in a certain predetermined pattern having smooth continuous lines whereby the electrode coverage varies as a function of transducer axial length.

Abstract: A passive sonar system which forms multiple receiver beams for detection of possible targets. The transducer array for the system includes a plurality of pairs of transducers, the transducers of each pair lying along a generally radial line emanating from a central point. The output signal from the outer transducer of each pair is delayed by 90.degree. or .lambda./4C relative to the inner transducer, and the delayed signal is combined with the output signal from the other transducer of the pair in a summing amplifier so that only one signal per transducer pair need be sampled by a multiplexer for transmission via a coaxial cable to beamformer apparatus. The concept is applicable to groups of transducers with more than just a pair, i.e., with three or more transducers. Appropriate additional delays are provided with all of the output signals and delayed output signals of a group being received by a single summing amplifier.

Abstract: A plurality of proximity sensors are disposed in a turbine flow guide to measure flow guide-to-turbine blade tip distance at various points around the flow guide. The sensor signals are detected and the peak-to-peak voltage of the detected signals provides an indication of the desired distance measurement. The signals are also monitored and if ambient operating conditions causes the signals to exceed predetermined positive or negative thresholds, corrective signals are generated so as to bring the detected signal back into an acceptable range. A proximity sensor is also provided to measure axial movement of the rotor to which the blades are attached so that the other sensor signals can be modified as a function of the measured axial position.

Abstract: Diagnostic apparatus utilized to monitor a steam turbine-generator power plant. A plurality of sensors around the plant provide data to the diagnostic apparatus which utilizes a digital computer to come to some conclusion relative to actual or impending malfunctions in the plant components. The computer utilizes an expert system diagnosis which establishes a plurality of subsystems which are generic and can be applied to any sensor to obtain indications of (a) sensor output movement, (b) validated sensor readings and (c) malfunction indications based on conclusions reached in (a) and (b).

Abstract: Sensor based diagnostic apparatus for performing on-line realtime monitoring of an industrial or other operating system. The diagnostic apparatus has a rule network for propagation of belief leading to one or more possible malfunctions of equipment in the operating system. The propagation of belief is dynamically altered as a function of the operating conditions of the sensors themselves.