Abstract: Method and apparatus for correcting reversal points for a traverse for guiding a strand from a reference wheel onto a spool utilize signals indicative of the angular velocity of both a reference wheel and the spool to determine first the actual spool radius at a reference point away from the spool's flanges, then determining the proper spool radius at each reversal point and then determining the actual spool radius at each reversal point. The actual spool radius and the proper spool radius at each reversal point are compared and if a difference greater than a predetermined amount is present, the reversal point is altered by a selected incremental amount.

Abstract: A data hub for facilitating and effecting data transfers between signal processors with high efficiency is disclosed. The data hub receives low priority data transfer instructions from a master CPU and is capable of transferring such low priority data between processors without imposing significant overhead burdens on either the data source or destination. The hub may have the further capability of asynchronously receiving intermediate priority data transfers, storing the received data and transferring it to a destination unit before any further low priority transfers are effected. The hub may have the further capability of asynchronously receiving high priority transfer requests which are effected by the hub before both intermediate and low priority transfers. The hub may be used as a keystone building block for use in linking signal processors.

Abstract: A printed circuit board heat sink retainer is disclosed comprising a mating pair of sawtoothed bars with slidably engaging teeth. The bars are laterally spread apart and held by a forcing device, which may be a screw or a spring, in order to push against and hold a heat sink in a channel. The distance between successive teeth may be constant in both bars or may be constant in one bar and may decrease in a direction toward the forcing device in the second bar.

Abstract: An angular velocity sensor utilizing the Coriolis effect on a fluid jet employs increased spacing between the sensing elements to increase the scale factor and to reduce flow disturbances. A metal diaphragm pump is utilized to improve the ability to control the flow rate. Flow disturbances are further reduced by using a single, symmetrical central flowhole, eliminating curtain holes, and providing only two discharge paths oriented 180.degree. apart.

Abstract: A piezoelectric phase modulator for a fiber optic sensor is disclosed. The disclosed modulator is capable of relatively large amplitude mechanical vibrations, i.e., having a large converse piezoelectric effect, while at the same time having a relatively predictable and well-behaved direct piezoelectric effect. This result is accomplished by bonding a relatively active piezoelectric material, such as PZT, to a relatively stable piezoelectric material, such as quartz. An optical fiber may then be bonded to the relatively stable material, or to a structure attached thereto, as part of a fiber optic sensor loop. Excitation of the relatively active piezoelectric material will then produce a mechanical vibration in the relatively stable material and in the attached fiber comparable in magnitude to that experienced by the active material. Several embodiments of the invention are shown which are illustrative of devices which may be made according to the teachings disclosed.

Abstract: Apparatus and method for controlling a variable speed wind turbine-generator at improved efficiencies is disclosed. The method and apparatus of the invention control the rotor tip speed below the limiting torque of the wind turbine at a selected constant velocity ratio with respect to wind speed and, above the limiting torque, control the rotor tip speed at speeds greater than those dictated by the constant velocity ratio up to a speed or power limit. This may be accomplished by controlling tip speed above the point where limiting torque is attainable to maintain optimal wind turbine performance along the performance envelope.

Abstract: A Remote Subsystem for monitoring a large number of parameters relating to operating equipment at a remote site is disclosed. A monitoring system having a plurality of local service offices each reporting to a central office and each having a plurality of remote subsystems at remote sites reporting to it is also disclosed. Each remote subsystem reports only a first alarm condition detected for a particular unit of equipment to its local office and reports the unit back in a normal operating condition only after all detected alarm conditions have returned to a non alarm status. In this way, the local and central offices are not inundated with information of little value. Each remote subsystem also monitors conditions that are indicative of impending alarm conditions in order to alert local and central service offices of developing problems in the field. Similarly, each remote system monitors and accumulates miscellaneous data useful for a variety of monitoring purposes.

Abstract: An active Q-switch integral laser cartridge is made of an acoustic transmitting body having a photoelastic laser medium in a part thereof for propagating and coupling both optical and acoustic waves. The photoelastic laser medium and the acoustic transmitting body may be made of substantially the same or similar base material.

Abstract: A variable speed wind turbine is controlled in a way which avoids the turbine lingering at a critical speed which would otherwise tend to cause excessive vibration. The disclosed method and apparatus increases speed at a selected rate with respect to generator output power except in the vicinity of the critical speed. The selected rate is changed in the vicinity of the critical speed to a different rate which is selected slower in the selected embodiment, to avoid commanding the critical speed. After the output power increases or decreases beyond the critical point, a deliberate discontinuity in the speed command signal is induced. A rapid speed change through the critical speed is accompanied by a corresponding power output change.

Abstract: A synchronizer for use in synchronizing individual signal processors in a multi-channel system is disclosed. Each synchronizer has a counter for counting its associated processor's clock pulses and, upon reaching a selected count, providing a counter frame output signal at an output thereof for use by each of the other synchronizers in the system. Each synchronizer has a voter responsive to counter output signals from each of the other synchronizers, and from itself as well, at input ports thereof. Each synchronizer's voter provides a frame sync (macro sync) pulse in each counter frame after receiving a selected number of counter frame output signals from any of the synchronizers in the system.

Abstract: A runtogether sensor comprising a balanced beam having a plurality of tines for insertion between a plurality of parallel wires in motion for sensing a pair of stuck together wires by means of a switch associated with the balanced beam for providing a signal indicative of a runtogether condition to an annunciator which provides verbal announcements of runtogether conditions, as well as other conditions to maintenance personnel for immediate corrective action.

Abstract: A variable speed wind turbine includes a frequency converter which converts variable frequency AC from a turbine driven AC generator to fixed frequency AC for delivery to a power grid. The frequency converter is typically an electronic cycloconverter or rectifier-inverter and is also used to control the power flow from the AC generator to the grid which thereby controls the air gap torque between the generator stator and rotor. The turbine speed is maneuvered to increase efficiency by precisely controlling the air gap torque according to a schedule defining sensed generator speed versus sensed generated power.

Abstract: An asynchronous bus interface circuit manages the transfer of messages between a host processor memory, and one of two redundant serial data buses by separately processing command words thereby permitting efficient handling of status and data words.

Abstract: A method and apparatus for integral control of a dependent variable in a system having at least two independent variables which influence the dependent variable is disclosed. A difference signal indicative of the difference between the sensed dependent variable and a reference is integrated and provided to a hysteresis transfer function. The output of the transfer function is subtracted from the integrated difference signal and the resulting signal is used to control an independent variable which thereby influences the dependent variable only for small magnitude signal variations in the integrated signal. The integrated signal is used to control another independent variable for large magnitude signal variations in the integrated signal. The other independent variable is typically only capable of influencing the dependent variable for large magnitude signal variations.

Abstract: A metal diaphragm impulse jet pump with no valves is disclosed. The pump may be used in an angular velocity sensor utilizing the Coriolis effect on a fluid jet. A magnetic core is mounted within an anvil and a drive coil is wound around the core. The drive coil may be driven sinusoidally and the diaphragm responds with a vibratory motion in like manner. Sensing poles are provided in quadrature with the drive coils and may be used to sense the vibratory motion and thereby control the fluid flow.

Abstract: A differential torquer having at least one bifilar winding mounted on the torquer is disclosed. The bifilar winding has opposing polarities and the torquer is particularly well suited for use in reducing the temperature sensitivity of torquer servo loops.

Abstract: An improved slave propeller SYNCHROPHASER.RTM. device and mode logic for a multi-propeller aircraft is disclosed. A designated master propeller has at least one associated slave propeller which has its speed and phase controlled with respect to the master by initially controlling the speed of the slave propeller to within a selected constant number of RPM of the master so that the master and slave propellers are periodically in phase and then switching to phase control for controlling the speed of the slave propeller in the presence of a phase difference signal having an absolute magnitude less than a selected absolute magnitude. A selected phase difference relationship between the master and the slave may thus be effected with minimum transient effect on the speed of the slave propeller.

Abstract: Circuitry is disclosed for automatically coupling an asynchronous half-duplex bipolar serial data bus to an asynchronous half-duplex unipolar serial data bus by means of extremely simple circuitry.

Abstract: An improved slave propeller synchrophaser (10) includes a first control (14) responsive to a phase difference signal (28) and a phase difference reference signal (26) for providing a phase error signal (112) and for providing a propeller speed reference bias signal (40) for a speed governor (46), and also includes, according to the present invention, a second control (12) responsive to the phase error signal (112) for providing an engine power reference bias signal (80) for an engine power control for providing a very limited amount of propeller fine speed control within the dead band of the propeller speed governor while at the same time substantially maintaining engine power at the commanded power level.

Abstract: Phase information in a multiple-coil indictive displacement sensor is retained by summing the excitation signal with each of the secondary signals to provide augmented secondary signals which may then be converted to a digital format. A signal processor may then be employed to extract both the magnitude and phase information from the augmented secondary signals by subtracting the magnitude of the primary excitation signal from each of the augmented secondary signals. The resulting signals retain both phase and magnitude information.