Abstract: A method of counting a plurality of pulses representative of randomly occurring events includes the steps of counting the number of pulses, having an amplitude exceeding a first threshold amplitude, which occur during a predetermined sampling period to obtain a first count and counting the number of pulses, having an amplitude exceeding a second threshold amplitude, which occur during the sampling period to obtain a second count. The second count is compared to a predetermined number and the counts for that sampling period are rejected if the second count is too large. If the second count is not too large, the true count is calculated by subtracting the second count from the first count. This counting procedure is repeated for a preselected number of successive sampling periods. After the final sampling period, all of the true counts are added to obtain an accumulated count and the accumulated count is multiplied by a scaling factor to obtain an output count.

Abstract: A wound capacitor end connection is constructed by spraying a first layer of metal onto one end of a capacitor winding, positioning strands of a stranded conductor adjacent to the first layer, without mechanically securing the strands to the first layer, and spraying a second layer of metal over the strands and first layer to mechanically and electrically connect the strands to the first layer. In an alternative embodiment, the stranded conductor may be replaced by a perforated conductor having openings which provide additional electrical and mechanical connection points between the two sprayed metal layers.

Abstract: Rectifiers mounted on the rotor of a brushless alternator are tested by applying an AC voltage to an exciter field winding of the brushless alternator. This applied voltage induces current in a rotor mounted exciter armature winding which is inductively coupled to the exciter field winding and produces current flow through the rectifiers. The magnitude of an even harmonic component of the exciter field winding current is measured and compared to a predetermined magnitude to obtain an indication of the operational status of at least one of the rectifiers. This comparison may be done manually or may be performed electronically in accordance with known techniques.

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 integrated circuit socket is provided with an insulating member and a plurality of conductive socket pins extending from the insulating member. These socket pins are adapted to be electrically connected to the pins of an integrated circuit. A plurality of impedance elements are mechanically supported by the insulating member. Switches are provided for selectively connecting each of the impedance elements to, or isolating each of the impedance elements from, at least one of the socket pins, thereby providing the flexibility to terminate any combination of pins on the integrated circuit.

Abstract: Voltage regulation of a DC electrical power source having a generator with an exciter field coil for producing an AC output voltage which is rectified to produce a DC output voltage, is accomplished by producing voltage signals proportional to the AC output voltage of the generator and the current in the generator exciter field winding, and combining these signals to produce a control signal. An additional voltage signal proportional to the DC output voltage of the power source is compared to a DC reference voltage signal to produce a trim error voltage signal. The trim error voltage signal is combined with an AC reference signal to produce an additional control signal. These control signals are compared and the result of that comparison is used to control the current in the generator exciter field winding.

Abstract: To leak test a cavity in a test item, a pressurizing gas, at a preselected pressure is applied to the test item and the flow rate of the pressurizing gas during pressurization is recorded. This recorded flow rate is compared with a threshold level based on gas flow signature data for a reference test item. If the recorded gas flow exceeds the threshold level, an excessive leak signal is produced. This leak testing method significantly reduces the time required to perform low flow rate leak detection in large volume test items.

Abstract: A microwave oscillator circuit having a voltage controlled oscillator for producing a controllable frequency microwave signal and a high overtone bulk acoustic resonator coupled to receive the signal is provided with a light source for directing a light beam onto the resonator such that the light is diffracted in response to the presence of acoustic waves produced in the resonator by the microwave signal. Diffracted and undiffracted portions of the light beam are measured and compared to provide an indication of resonance phenomena within the high overtone bulk acoustic resonator. This technique is particularly applicable to frequency agile stable local oscillators in radar equipment. Optical data extraction is completely non-invasive with respect to the microwave circuit functions, resulting in unimpaired stable local oscillator operation.

Abstract: A tinning station for axial lead electronic components includes a presentation system for arranging a plurality of axial lead components in an elevated linear array with adjacent components lying parallel to each other. A pair of grippers, have a pair of parallel bars each having a longitudinal slot and a length at least as long as the length of the component array. These bars are moved toward or away from each other by an actuator which is mounted on a robotic arm. This arm is programmed to position the grippers adjacent to the array so that the actuator can cause the grippers to clamp the ends of the bodies of the components in the array. Then the arm dips the leads on each side of the array into the solder flux and subsequently into molten solder, thereby tinning the leads. The thickness of the grippers defines an untinned length of each component lead. A release fixture is used to dislodge any components which do not fall from the grippers when the grippers are separated.

Abstract: Power sources of a parallel AC electrical power system are synchronized by producing a voltage difference signal representative of the difference in output voltages of the power sources and demodulating that signal to produce a frequency control signal and a voltage magnitude control signal. The output frequency and voltage magnitude of at least one of the power sources is varied in response to the frequency control signal and voltage magnitude control signals, respectively, to minimize the difference in output voltages between the power sources.

Abstract: An absolute shaft position sensing circuit uses a magnetic sensor and a toothed wheel to produce two pulse trains which are used to determine the absolute position of a shaft which is coupled to the toothed wheel. One pulse train includes regularly spaced pulses which are fed to a phase locked loop to produce an oscillating output signal. A counter counts this signal and produces an output count which is representative of the relative angular position of the shaft. A second pulse train includes an irregularly spaced pulse. Circuitry is provided to detect the occurrence of this irregularly spaced pulse and to reset the counter in response to that occurrence, thereby making the count representative of the absolute angular position of the shaft.

Abstract: A DC link variable speed constant frequency power system is provided with a voltage boost circuit connected to receive voltage from a pair of DC link conductors and to supply voltage to an auxiliary supply bus. During normal system operation, the voltage boost circuit transfers the DC link voltage to the auxiliary supply bus. When a system fault occurs, such that the DC link voltage is reduced, the voltage boost circuit is activated to boost the reduced DC link voltage level and supply that boosted voltage level to the auxiliary supply bus.

Abstract: A sub-nanosecond rise time megavolt pulse generator is disclosed. The generator utilizes an induction energy store together with electron beams for generating a sub-nanosecond high voltage pulse wave-front. The electron beams are deflected to establish the wave-front. In a preferred form multiple electron beams together with a waveguide of particular shape provide simultaneous converging wave-fronts that are directed to a local area.

Abstract: A power active filter circuit for an electric power system includes a reference generator for producing a plurality of balanced, constant amplitude, positive sequence, AC reference voltages, each being phase-locked to a corresponding phase voltage of the power system. Error signals are produced by subtracting the reference voltages from their corresponding phase voltages and a plurality of correction signals, which are proportional to the error signals, are combined with the phase voltages to produce a plurality of output voltages having substantially only a fundamental component.

Abstract: A control circuit for controlling the operation of a parallel source electrical power system produces a pair of load current signals representative of the load current delivered by corresponding phases of individual channels of the power system. At least one of the load current signals is scaled by a scaling factor to obtain a scaled load current signal that is combined with the load current signal for the other channel to obtain a feedback signal. The feedback signal is used to control the output of one of the paralleled power sources such that the ratio of load currents delivered by the power sources is proportional to the scaling factor.

Abstract: Three terminal, six and twelve pulse unrestricted frequency changing circuits are provided by inserting controllable bidirectional switching circuits between open star configured coils in multiple phase windings of isolation transformers. Where the switched winding are secondaries of the isolation transformer, interphase transformers are provided between each pair of three pulse circuit groups and additional interphase transformers are required between six pulse circuit groups to provide a three terminal output. Where the switched windings are primary windings of the isolation transformer, the secondary windings are electrically connected in series with each other to provide the three terminal output.

Abstract: A starter generator system is provided with a dynamoelectric machine having a stator and a rotor which is mounted for rotation with respect to the stator. The rotor carries a main field winding, an exciter armature winding and means for rectifying the output of the exciter armature winding to provide DC excitation for the main rotating field winding. A main armature winding is mounted on the stator and magnetically coupled to the main field winding. An exciter portion of the stator supports both a multiple phase AC exciter field winding and a distributed DC exciter field winding, both of which are mounted to be magnetically coupled to the exciter armature winding. A variable voltage, variable frequency power converter is capable of being alternatively connected to drive the dynamoelectric machine as a starting motor or to receive power from the machine during generator operation.

Abstract: A projectile for use in an electromagnetic projectile launcher is provided with a conductive open loop which is mechanically attached to the body of the projectile. Means are provided for electrically connecting the open loop between a pair of generally parallel projectile launching rails when the open loop is in a predetermined angular orientation with respect to the rails. Current flowing in the loop then interacts with magnetic flux produced by current flowing within the rails to place a torque on the loop which can be used to spin-stabilize the projectile or to prevent rotation of the projectile depending upon the particular application.

Abstract: A continuous wave radar system arrangement for improving the dynamic range of the radar receiver. The transmitted carrier signal is frequency modulated by a periodic sawtooth waveform causing a predetermined peak frequency shift. The radar receiver includes a plurality of separate receiving channels each selective to a small portion of the transmitted bandwidth. As the sawtooth modulation causes the carrier signal to sweep in frequency, the received leakage and clutter signals in the selective receiving channels are blocked momentarily and individually in each channel. The outputs of the separate receiving channels are combined to form a composite signal of the echo returns. Gaussian filters with quadratic phase compensation are used to provide the selectivity of the receiving channels.

Abstract: An electromagnetic interference filter assembly includes a pair of magnetic cores each having a central opening. The cores are mounted with their openings aligned along a common axis and feedthrough conductors pass through the openings. Two arrays of capacitors are mounted on opposite sides of the cores and capacitor bus bars serve to electrically connect corresponding ones of these capacitors in each array. A portion of each capacitor bus bar includes an aperture which is aligned along the common axis and through bolts which lie along the common axis are used to hold the feedthrough conductors and capacitor bus bars in electrical contact with each other.