Abstract: In a steam turbine control system three overspeed protection circuits (OPC) are provided, each one being identical to the others and each having a programmable digital computer in two-way data communication with a master controller, as well as with the other OPCs. Speed transducers adjacent the turbine shaft provide speed indicative signals to the respective OPCs which calculate extremely precise RPM values utilizing an adaptive filter in the derivation process.

Abstract: A forward look sonar system in which speed and direction of a sonar platform is obtained. Each acoustic transmission towards the target area over which the platform is traveling is comprised of a plurality of frequencies. A plurality of receiver beams is formed and each individual beam from one transmission is cross-correlated with its corresponding beam from a selected subsequent transmission to derive a delay value. The later received signal for each beam, for each frequency is divided into a plurality of small segments each of which is cross-correlated with a portion of the first return signal corresponding to the same frequency and beam. The cross-correlation functions for the plurality of frequencies for each particular segment are added together to obtain a more precise delay value. The correlation functions for each of the beams are added together and compared to derive a value for platform direction in the intercomparison period and the delay values are utilized to derive a velocity indication.

Abstract: Apparatus which measures temperature in the high voltage environment of an electrical generator includes a temperature sensing element which includes a polarizing filter rotatable as a function of temperature. Light from a source is passed through the filter and the polarized light is again polarized through the use of a constantly rotating second polarizing filter behind which is a detector operable to provide an AC signal as a function of the doubly polarized light intensity. A reference beam is passed through the second rotating filter as well as a manually rotatable polarizing filter and is detected so as to provide a second AC signal. After an initialization, the AC signals are compared in phase, with the phase difference between them being a function of the temperature being measured.

Abstract: Apparatus which provides both range and bearing information between a transponder and a transponder interrogator. The interrogator transmits an acoustic interrogating pulse which is received by the transponder and in response thereto transmits back a first signal of a certain frequency f1. Two spaced apart hydrophones on the transponder provide their respective output signals to a phase meter, the output signal of which is indicative of the direction, that is, bearing, from which the interrogating pulse impinged. The phase meter output is converted to a corresponding time delay after which a second signal of a frequency f2 is transmitted. A counter in the interrogator starts counting upon transmission of the interrogating pulse and stops upon reception of the first signal of frequency f1. A second counter of the interrogator starts its count when the first counter turns off and terminates its count when the second signal f2 is received.

Abstract: A generator having stator windings which are water cooled includes a plurality of sensors each for measuring the temperature of cooling water as it is discharged from respective sections of the stator windings and prior to its collection in a common manifold. The outputs of the sensors are combined to obtain an average reading and during an initialization process, each sensor reading is subtracted from the average to derive a correction factor for that particular sensor, for that particular average. The generator is operated so that other averages are selected for the calculation of other sensor correction factors. When operating on line, the correction factors are utilized to obtain a value for a percent of average coil temperature in accordance with the relationship: ##EQU1## where T is the temperature indication provided by the sensor, AVG is the average of all of the sensor readings, and CF is the appropriate correction factor for that sensor for that average.

Abstract: A magnetostrictive transducer utilizing magnetostrictive material and a plurality of windings connected to current sources having a phase relationship so as to establish a rotating magnetic induction vector within the magnetostrictive material.

Abstract: A towed body deployment/retrieval system which includes first and second hollow arms for passage of a cable from a winch to the towed body. The adjacent ends of the arms include forked fittings which are in cooperative engagement with a slip boundary sheave having, in a peripheral channel thereof, an endless belt slidable in the channel and having a groove which receives the cable. The arms are movable relative to the slip boundary sheave over a limited distance during normal usage. The slip boundary sheave rotates about an effective center located outside of its contour and accordingly is much smaller and can fit into a smaller space than an equivalent circular sheave which would normally be required for the same diameter towing cable.

Abstract: A speed feedback loop for load control regulation of a steam turbine. A difference between rated and actual turbine speed results in a speed error to which a deadband function is applied. Operation is such that the deadband, rather than being centered about a fixed value, moves as a function of speed error.

Abstract: A sine wave generator which utilizes a PROM for storing a predetermined bit pattern which is converted to a corresponding pulse waveform generated in response to a very accurate and stable clock pulse. The pulse waveform is shifted to a very exacting voltage level and is filtered by a band-pass filter to derive the desired fundamental frequency sine wave. The amplitude and frequency stable sine wave may be utilized in linear variable differential transformer (LVDT) apparatus for measuring the position of a controlled object such as a turbine valve. The arrangement may also be utilized for generating additional sine waves bearing some predetermined phase relationship with respect to one another for other control or signal processing applications.

Abstract: An electric discharge gas laser utilizing a seedant material which is cooled prior to the main laser discharge. The seedant is ionized prior to the cooling process and prior to the main discharge, this pre-ionization maintaining the seedant material in a gaseous state even in view of the lowered temperature for a sufficient time so as to give the required ionization levels.

Abstract: A steam turbine generator power plant which includes a main steam bypass path and an auxiliary steam bypass path which bypasses the high pressure turbine. The auxiliary bypass path includes a steam jet compressor which functions to pump up the pressure at the high pressure turbine exhaust to a value compatible with discharge into the main bypass path, and does so in response to measurement of the high pressure turbine output temperature.

Abstract: A plurality of sensors are disposed equally about a blade row in a turbine with each sensor being operable to provide an output signal in response to a passing blade. A blade is selected for monitoring purposes by designating its degree location relative to a reference position .+-. some angular distance constituting a small window. As the selected blade passes a sensor, its output signal, properly conditioned to form a pulse, is gated during the time period corresponding to the window. The sequential pulses of the sensors form a pulse train which is modulated by any blade vibration. An FM detector is provided for demodulating the pulse train to derive vibration information.

Abstract: A torpedo having a nose section wherein the entire nose section is of a porous material. The volume behind the nose is divided into a plurality of annular chambers and a fluid delivery system provides filtered sea water to the chambers for expulsion through the porous nose. The filtered water passing over the nose and torpedo body is at a rate to alter the trajectory of any particulate matter that would tend to destabilize laminar boundary layer operation.

Abstract: An eddy-current sensor having a thimble shaped alumina housing into which is positioned first and second coils wound about an insulating coil support. A Kovar sealing ring seals the alumina housing to a metallic base member to which is secured a protective tube carrying an electrical cable which makes electrical connection with the coils. A multifaceted nut secured to the metallic shielding of the cable nestles within a complementary shaped insulating member to prevent the cable from being twisted or withdrawn from the sensor thus maintaining electrical integrity.

Abstract: A rub detector for rotating machines such as turbines wherein a grounding arrangement for the turbine rotor is monitored to detect coincidence between a rotor potential discharge and resulting current flow through the grounding arrangement. In the absence of such coincidence, a rub is suspect. In another arrangement in which a grounding strap is utilized, the strap is elevated from ground by means of a diode arrangement and the rotor voltage is monitored and compared with a predetermined reference which may not be exceeded. If the reference potential is attained by the rotor, then the rotor is discharged such that during cyclical operation, a certain discharge waveform is produced, and which waveform is modified in the presence of a rub condition. Means are also provided for imparting a potential to the rotor during initial start-up conditions.

Abstract: A steam turbine control system which includes a manual panel with pushbuttons for operator control of the steam admission valves. Each valve has its own control means and is responsive to pushbutton activation to govern its valve movement. If a pushbutton indicating valve opening or closing gets stuck, the operator pushes a pushbutton indicating opposite movement and the control means switches to a special control mode after a predetermined period of time. In the special mode valve movement stops after removal of the operator's finger pressure and valve movement is accomplished by activation of predetermined pairs of pushbuttons.

Abstract: Hydraulically operated turbine steam admission valves wherein each valve has its own microcomputer control. In the event the valve gets stuck due to possible contamination in the hydraulic system, the microcomputer control provides an oscillatory control signal to dither the valve. If the valve remains stuck after dithering action it is provided with a control signal of an initial magnitude greater than that normally required to close the valve.

Abstract: An optical fiber cable wherein the optical fiber is cushioned with an elastomeric material around which is provided a protective cladding of a liquid-crystal material.

Abstract: An electrical penetrator for use in high pressure situations includes a metallic penetrator body having a central aperture therein which includes a conical portion and a cylindrical portion. An electrically conducting pin member fits within the aperture and has a cone portion which fits within and is displaced from the conical surface portion. An encapsulating compound maintains the pin in its proper orientation displaced from the interior walls of the aperture with the compound including a polyamide cured epoxy resin mixed with silica.

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.