Abstract: In circuit modifications of dual in line packaged (DIP) devices are realized by a circuit modification device that interfaces the DIP and its companion device. A first pair of single in line packaged (DIP) header pins are mounted on a printed circuit (PC) board such that they form a socket for the DIP device. A second pair of SIP header pins are mounted adjacent to the first pair and extend through the PC board to form a plug for the companion device. Header pins are interconnected by the printed circuit to effect the desired DIP device circuit reconfiguration. Packaging is accomplished with commercially available components and does not impact system size, weight or power constraints.

Abstract: The performance of an adaptive digital doppler tracker having a sample data phase locked loop is improved by a circuit that detects and demodulates interfering signals. The tracker has a coherence sensor that provides signals indicating coherence and non-coherence conditions. An amplitude sensor generates a strong signal when interfering (time coincident) signals are received. The tracker includes both a coherent data detector and an SSB processor. An interference detector receives the outputs of the coherence sensor and the amplitude sensor and generates an SSB enable signal in response to the coincidence of a strong signal and a non-coherent condition signal. The SSB enable signal disables the coherent data detector and enables the SSB processor which detects both interfering signals.

Abstract: Precise phase acquisition and tracking of a data modulated pulse signal in order to recover the data in a low signal to noise ratio environment is achieved by a sample data phase locked loop that is adaptive, second order, and uses baseband polar coordinate processing. The circuit utilizes an adaptive second order loop where the loop bandwidth can be adjusted by a coherence measurement. This provides wide bandwidths during initial acquisition, medium bandwidths during acquisition/track transition and narrow bandwidth during tracking.

Abstract: The inherent temperature instability of surface acoustic wave (SAW) clock oscillators is improved by the use of a thermometer oscillator circuit that senses temperature changes in the SAW substrate. The thermometer oscillator is used in combination with a calibrated programmable read only memory and a logic circuit and provides frequency corrections to the clock oscillator. The basic device is an oscillator clock circuit using a SAW substrate having a delay path orientation with good temperature stability. A second oscillator, the thermometer oscillator circuit, and the electronic compensation scheme are added in order to produce minimum temperature coefficient of delay over all temperatures in the range of interest. The thermometer oscillator delay path utilizes a high temperature coefficient of delay orientation of the same SAW substrate and at an appropriate angle to the clock oscillator delay path orientation.

Abstract: A power circuit utilizing a switch comprised of Hall-effect-active resistive elements for interrupting a current flow in an inductive energy storage system. Interruption of the flow of current causes a high-voltage pulse which drives the current flow into a circuit leg which is parallel to the interrupting elements. The Hall effect switch is controlled by means of an exciter coil that is connected in parallel with the Hall-effect-active resistive elements to provide self excited operation.

Abstract: A synchronous digital delay line that can be programmed by variable delay increments to independently delay the leading and trailing edges of a digital signal and that can be utilized to provide a wide range of digital delaying requirements. Bipolar input data is processed to develop a mark data pulse stream representing the leading edges of input data pulses and a space data pulse stream representing the trailing edges of input data pulses. Each data pulse stream is delayed separately by a programmable random access memory delay circuit and the delayed outputs are recombined by a line driver latch to provide output data pulses that are delayed, delayed and compressed, or delayed and stretched in accordance with the programmed delays and system requirements. The programmable random access memory delay circuits each comprise a random access memory used as a variable length register having an address counter operating as a ring counter.

Abstract: A programmable arithmetic logic unit for performing high speed bit sliced, pipelined computations at very low power is fabricated as an LSI component using CMOS/SOS technology. It is microprogrammable and operates in conjunction with a fast microprogram store program memory and controller. Dual input ports which supply data from eight sources are latched and operated on while new data is simultaneously fetched. Instruction bits shift data in either port left or right, select complements and select an operand between device input and output data in one port. The data processed in each port is compared and is added to provide a latched tri-state output to an external device.

Abstract: A precision digital sampler utilizes a sample rate clock providing pulses driving a tapped delay line where the total delay equals the Pulse Repetition Interval (PRI) of the sample clock. The outputs of the tapped delay line are tied to a buffer register having a storage cell for each delay line tap. The data from the delay line is stored in the register on receipt of a command signal designated "sample initiate command". In storing the outputs of the delay line, the state of the sample clock is known to the resolution of the taps. A decoder studies the states and the time for locating the leading edge of the sample clock is calculated. The calculated time is used by a control switching circuit to determine which tap should be enabled. The leading edge of the sample clock is thus enabled at the resolution of the delay line taps.

Abstract: A metal vapor laser, and, in particular, a lead vapor laser having a main discharge tube mounted within a pair of electrode support collars. A discharge electrode is mounted at one end of the laser which is sealed by a conventional window and reflector assembly. One of a pair of recirculating wick structures is situated adjacent the discharge electrode and is supported by an elongated support collar outside of and adjacent an end of the main discharge tube. In addition, this wick structure is isolated from the support collar by a separate auxilliary tube. The auxiliary tube is situated in abutting relationship with the end of the discharge tube. This recirculating wick structure does not protrude into the main discharge tube and is kept separate therefrom. A metal foil thermal shield is isolated from the main discharge tube and electrode collar by insulating standoffs. Such an arrangement allows for a high output lead vapor laser in which discharge tube breakage is essentially nonexistant.

Abstract: Alarm and intrusion type identification signals are derived from the output of a security system transducer by a signal processor. The signal processor conditions the transducer output signals to provide rectified and unrectified high pass and low pass frequency signals; develops signals representing either human or vehicle intrusions from the high pass frequency signals; develops signals representing intrusion events from the low pass frequency signals; and, logically classifies each intrusion event as either human or vehicle. Intrusion type identification signals are developed by counting zero crossings of the unrectified high pass frequency signal, measuring current energy of the rectified high pass frequency signal and logically comparing the two values.

Abstract: Sequential firing of strings of flashbulbs arranged in a parallel array is controlled by a shift register that functions in response to an IC 555 timer. The timer delivers a pulse train (the PRF of which can be set for appropriate firing intervals) that drives the shift register which in turn provides firing signals sequentially from each stage. The firing signals are applied to the gates of silicon controlled rectifiers that are located in each flashbulb string. Firing due to spurious signals is prevented by diodes that short each silicon controlled rectifier gate to ground through a normally closed relay contact. During the arm and fire operational sequence the relay contact opens removing the ground from the silicon controlled rectifiers and enabline their operation.

Abstract: A current transformer and copper sulfate water resistor are combined to provide a probe capable of measuring very fast, high voltage pulses. The resistor is connected in series with the primary winding of the current transformer and consists of an elongated plastic tube filled with an aqueous solution of copper sulfate. The series arrangement of resistor and current transformer primary winding is applied across the source of voltage to be measured and the current transformer secondary winding output is a function of the measured voltage. The current transformer secondary output is applied to and displayed on an oscilloscope.

Abstract: A multifrequency antenna for a missile is realized by an arrangement in which four microwave antennas are located under a narrow circumferential slot in the skin of the missile forming four separate antennas each with its own input connector. Each antenna consists of a probe fed annular quarter wavelength microwave cavity which radiate out of a top wall end slot. The cavity antennas are fed by a stripline distribution network directly under the antennas. Two L band antennas are positioned directly adjacent the inner surface of the missile skin and an S band antenna and a C band antenna are positioned beneath the L band antennas. A radome covers the circumferential slot.

Abstract: An input-output converter permits the integration of terminals and transmit and receive equipments that operate at given logic voltage levels and character formats into communications system that operate at different logic voltage levels and character formats. The input-output converter includes a universal asynchronous receiver transmitter that converts m bit serial data into n bit parallel data in a receive mode and n bit parallel data to m bit serial data in a transmit mode while stripping and adding asynchronous start-stop bits. The input-output converter also includes logic voltage level converters that convert digital data to appropriate logic voltage levels for each function.

Abstract: The detection and indication of volleyball out of bounds occurrences is realized by means of a light beam type system that distinguishes between the volleyball and other beam disrupting agents. Two juxtaposed light beams, one over the other, and separated by a distance equal to 1.5 volleyball diameters are projected along and 0.5 volleyball diameters outside of the sideline and endline bounds of the volleyball court. The beams are separately monitored by detectors that respond to beam interruptions. The lower beam is spaced from the playing surface by about three inches. Visual out of bounds indicators are actuated by a control circuit that responds exclusively to lower beam interruptions.

Abstract: The maximum instantaneous value of analog signals from multiple sources is detected by means of an analog OR gate circuit in which the analog signal from each input is connected to both a positive and a negative half wave rectifier circuit. The outputs of the positive half wave rectifier circuit are OR wired together and the outputs of the negative half wave rectifier circuits are OR wired together and the OR outputs of both are summed to provide an output signal that is the maximum peak instantaneous signal. Because the maximum instantaneous signal from any channel reverse biases the other rectifiers, other signals are neither added nor subtracted from the output.

Abstract: An acoustic target sensor and ranging system automatically detects military targets and provides a munition firing signal at the appropriate target position and time. An amplitude-doppler circuit is utilized to predict the time of closest approach to a munition by a target by measuring the time interval between zero crossings of the second and third derivatives of the received acoustic wave amplitude function. The circuit produces a firing signal by logically ANDing the closest point of approach signal it develops with a signal that indicates when target range is within specified limits. The circuit is realized by means of conventional electronic zero crossing detectors, an up-down counter, dividers, sample and hold devices and voltage comparators. The acoustic target signal is obtained from an omni-directional microphone the output of which is amplified and rectified.

Abstract: The selection and designation of an aimpoint on a known type of target appearing in the field of view of a video tracking system imaging sensor is accomplished by (a) developing binary target patterns from quantized sensor data generated in the video tracking system video preprocessor; (b) measuring the moments of the target patterns; (c) developing and storing a target reference pattern data base; (d) computing from real time binary coding and moment measurement data and from the stored target reference pattern data base an ensemble of estimated aimpoints; (e) testing the validity of the estimated aimpoints; and (f) averaging valid estimated aimpoints to provide an output aimpoint signal. Mechanization of the invention comprehends the use of video tracking system functions to provide quantized binary coded target patterns and the use of dedicated accumulators to generate pattern moment measurements.

Abstract: Munition actuation signals are generated by an acoustic target ranging system that predicts the time and distance of closest approach of a moving target to a munition. The predictive capability of the system is based on the rate of change of the sound level emanating from the target compared to its absolute magnitude. The system generates munition standby, arm and fire signals by differencing the received acoustic amplitude function signal and its first derivative and subsequently comparing the difference signal with various reference level signals. The reference level signals are a function of munition effective range and target conditions. Mechanization of the system is realized by simple circuitry consisting of an acoustic signal detector and processor, a differentiating operational amplifier, a programmable gain amplifier, a reference level signal source, an adder and a comparator circuit.

Abstract: A maintenance training system capable of precisely simulating both the inner and the outward functions of original electronic equipment is realized by utilizing a programmable waveform generator, a microcomputer and interfacing input/output circuits in a modular design that can be adapted to use with virtually any desired electronic system maintenance trainer. The system provides genuine waveform generation and display in a real time maintenance trainer with positive input/output control through line replacable unit read/write modules. The programmable waveform generator develops analog waveforms from digital control and picture data received from the micro-computer. The analog outputs of the programmable waveform generator drive the maintenance trainer's external meters, displays and oscilloscope and can be programmed to simulate point by point circuit tracing of the original electronic equipment.