Abstract: During assembly of a motor, a stator winding is installed in a jig in preparation of cleaning. A brush is moved axially through the central space of the winding. The shaft of the brush is equipped with fluid jets which direct solvent against the winding as it is being brushed. Dislodging of foreign matter from the winding is enhanced by pumping the solvent through the brush shaft in a pulsating manner.

Abstract: An inertial measuring unit gyroscope wheel dynamic braking and sequence inhibiting circuit is disclosed. The circuit comprises a first counter for counting a specified time interval and digital logic circuitry for applying an in-phase signal to the phases of a multiphase electric induction motor driving a gyroscope wheel during the time interval, for example, a vertical gyroscope motor wheel. By placing in-phase signals on the inputs of a multiphase electric induction motor, the motor is brought completely to rest in a short time by dynamic braking. In a preferred embodiment, a second counter counts a second specified time interval after the first time interval has terminated, during which second time interval a second electric induction motor is dynamically braked, for example, an azimuth gyroscope wheel motor. During the time period when the motors are braking, a signal is fed back to an automatic sequencing circuit to inhibit further sequencing of the inertial measuring unit.

Abstract: The torquer section of a gyro includes a plurality of torquer coils symmetrically positioned within a flywheel. A pair of parallel spaced radially oriented salient torquer magnets are located within the flywheel and are equidistant to each respective coil. The magnet pairs increase the flux density within the operating gap between coil and magnets while minimizing fringing flux. The torquer section is secured to the gryoscope housing by mounting materials which reduce unwanted thermal gradients during rapid warmup and high torquing rates thus virtually ensuring consistent torquer coil position over the operating temperature range.

Abstract: This solderless electrical connector for an electrical cable consists of a helical spring and loop joined together to form a ring. The helical spring provides a snug fit on a matching cylindrical post while offering strain relief protection for the electrical cable, which is routed through the helix of the spring.

Abstract: An inertial measurement unit using body dithered ring laser gyroscopes in which the individual ring laser gyroscopes are firmly attached to a common dithered structure and provisions made to cancel the reaction moment from the dithered structure by a passive resonator. The stable element, to which both the dithered structure and the passive resonator are attached with torsion springs, also serves as a non-vibrating foundation for strapped down accelerometers. The resulting structure contains fewer parts, has lower fabricating cost and permits a smaller package size than a conventional inertial measurement unit with individually body dithered ring laser gyroscopes.

Abstract: A multiplexed analog-to-digital converter is provided for use in an inertial navigation system comprising a multiplexer, a buffer, a feedback stabilized ramp generator and a comparator controlling a gated counter whose digital output is representative of the analog input signal.

Abstract: A ring laser gyroscope having a triangular block configuration is dithered about its center of gravity. An optical wedge attached to the output mirror allows the center of support to include the line of symmetry of the block, thereby reducing temperature gradients, which could cause output signals in the absence of an input angular rate across the instrument. The optical wedge, a mirror and a beamsplitter form an interferometer to compensate the output signal of the ring laser to produce an output free from influence of the dither motion. The mirror and beamsplitter are adjustable to allow for small corrections necessary to exactly compensate the dither-motion and to achieve 90.degree. phase shift between the outputs from photodetectors.

Abstract: A magnetic resonance gyroscope has auxiliary coils mounted adjacent the coils which normally produce the DC H.sub.o field for the gyro spin generators. The auxiliary coils establish an inhomogeneous H.sub.o field which results in a reduction of the rate bias shifts due to readout lamp plasma shifts. Alternately, rate bias shifts may be reduced by introducing a temperature differential between the two absorption cells employed in the gyro.

Abstract: A piezoelectric pick-off transducer is used for sensing dither velocity in a ring laser gyroscope. The pick-off transducer is mounted on a spoke connecting the hub and rim of the gyroscope and it comprises two spaced electrodes equidistant about the point of inflection of the spoke. A differential amplifier is connected at its input to the electrodes for generating a signal proportional to dither velocity.

Abstract: A magnetic resonance gyroscope wherein the pump lamp includes an isotopic mixture of Hg, which controls the optical spectra of the pump beam to eliminate .sup.201 Hg alignment moments and to reduce light-induced frequency shifts. The inclusion of quarter-wavelength plates, reflection polarizers, and adjustable magnetic fields acting on the pump and readout lamps permit fine tuning control over the respective spectra to further enhance the rate bias stability of the gyroscope.

Abstract: A gyro includes a rotatable hub with a flexing member centrally supporting a rotor. The rotor is further supported by a pair of piezoelectric force transducers angularly separated by 90 degrees. The rotor turns with the hub. Oscillators drive the transducers and, as the gyro undergoes angular displacement, the oscillators "follow" the instant natural frequency of the transducers. FM signals are generated which may be resolved into two digital signals indicative of angular rate about the gyro case X and Y axes.

Abstract: Bias shift caused by distortion of a ring laser gyroscope block is corrected by bending the block. Electromechanical bending devices may be piezoelectric crystals adherently attached to the block and resposive to voltage derived from distorting influences.

Abstract: A stand-alone digital processor based system includes a five-output state digital filter provided with magnitude and time data relative to a received TACAN signal. Threshold detection is provided for validating the received signal magnitude. The filter outputs produce phase signals which are combined in the digital processor, in accordance with an algorithm, to generate bearing data. The bearing data is stored and scaled prior to updating a display.

Abstract: A transducer for driving a spoke of a ring laser gyroscope is fastened at a point of neutral radius on the spoke. The transducer may be a piezoelectric crystal provided with a pair of electrodes which are driven in push-pull by an AC voltage to dither the gyroscope.

Abstract: A transimpedance amplifier is connected in a positive regenerative loop with a crystal resonator. The transimpedance amplifier includes a high gain amplifier with a parallel resistor and capacitor thereacross. A virtual ground is created at the node between the resonator and the amplifier input thereby eliminating circuit sensitivity to inherent capacitive changes between the resonator and true ground. Components are chosen to maintain oscillations at series resonance and achieve insensitivity to changes in the motional resistance of the resonator.

Abstract: The complexity of a memory driver system is decreased by minimizing the number of half-select current driver circuits and corresponding terminals and wires connected between the driver lines and the core stack. This is effected by maximizing the number of current paths between memory drivers.

Abstract: Electrical and mechanical synchronization of two or more synchronously driven gyroscopes, mounted on the same platform, to minimize cross-talk induced drift, is achieved by bringing one gyroscope to a speed which is slightly higher than the other by driving it at a slightly higher frequency. At speed, coincidence of mechanical position is established by means of signals from pick-offs on each gyro and the drive for the faster gyroscope is shifted to the lower frequency. Electrical synchronism is established by restarting the lower frequency generator to instantaneously establish a predetermined relationship between a pick-off signal and the frequency generator. Phase-lock start-up of a single gyroscope by instantaneous shift of the phase of the driving voltage, relative to the gyroscope wheel position, is also provided.

Abstract: An electro-static capacitive accelerometer is a square law device and includes two fixed plates and an intermediary movable plate. A control circuit detects unbalances in the accelerometer, due to acceleration, and generates a signal which induces a corresponding electro-static corrective torque on the accelerometer thus forcing it toward a null condition. The signal is proportional to the acceleration. The invention eliminates prior art summing amplifiers in the control circuit for linearizing the torque of the accelerometer.

Abstract: A digital to analog converter is provided, for making a digital to analog conversion, and including, an analog to digital converter portion which may be an existing converter, an arithmetic logic unit which is coupled to the analog to digital converter portion, a digital to dc converter portion which is coupled to the arithmetic logic unit, an ac multiplex circuit for an ac operation which is adapted to be coupled to the digital to dc converter portion, a dc multiplex circuit for a dc operation which is adapted to be coupled to the digital to dc converter portion, a switch which couples either the ac multiplex circuit or the dc multiplex circuit to the digital to dc converter portion and which is coupled to and operated by the arithmetic logic unit, and a multiplex control which is actuated by the analog to digital converter portion and which is coupled to the ac multiplex circuit and to the dc multiplex circuit for controlling the output signals from the ac circuit and dc circuit to the analog to digital con

Abstract: A low cost, simple to manufacture, two axis gyro having an outer flexure assembly and an inner flexure assembly. Each flexure assembly contains two flexure hinges which represent a reduction in the number of hinges and milled cuts from those required in prior art devices. The inner flexure assembly is designed to nest within the outer flexure assembly and both are mounted centrally on a rotatable shaft for rotation about the gyro spin axis. The two flexures of the outer assemblies are separated 180.degree. from each other and adjacent to two slots also separated by 180.degree. in the rim of the outer gimbal. Likewise, the two flexures of the inner flexure assembly are separated 180.degree. from each other and 90.degree. from each of the outer flexures. The outer flexure assembly axis is offset axially by a controlled amount from the inner flexure assembly axis to achieve nominal balance on both flexure axes.