Abstract: A shaped bridge slapper having a pair of spaced conductive lands on a substrate; a bridge member between the spaced conductive lands, the bridge member having a curved shape and a cavity herein, and a flyer layer extending over the bridge member.

Abstract: A ballast circuit for a high intensity discharge lamp includes a boost converter, responsive to a dc input voltage, for providing a boosted dc output voltage; a boost controller, responsive to the boosted dc output voltage, for driving the boost converter to maintain the boosted output voltage at a predetermined level; a buck converter, responsive to the boosted dc output voltage, for providing a reduced dc output voltage; and a buck controller, responsive to the reduced output voltage, for driving the buck converter to operate the discharge lamp in a transition mode and maintaining the reduced dc output voltage at a preselected level for operating the discharge lamp in a steady state mode.

Abstract: A general purpose programmable optical analyzer employs a nonlinear gain at the input stage of an analog to digital converter in order to limit the number of bits used to resolve shot noise.

Abstract: Apparatus for filling an electrophoresis cassette of the type having a gel layer between two glass plates. The filling system includes a filling manifold which is brought into abutment with the bottom edges of the glass plates. A rubber gasket provides a seal between the manifold and the cassette, The gasket includes a trough extending along the bottom edge of the cassette which communicates with an opening adapted to receive an injector. Liquid gel material in the injector fills the cassette from the bottom to the top.

Abstract: A light beacon for marking tall obstructions which may present a navigational hazard to air traffic comprises a transparent cover and a plurality of linear light sources, each having a central axis. The linear light sources are positioned within the transparent cover in a substantially horizontal orientation relative to a reference plane which will typically be parallel to the horizon. The plurality of reflectors corresponding to the plurality of linear light sources are positioned behind respective ones of the light sources. Each of the reflectors has an optically reflective surface and is configured as a partial cylinder having a parabolic or pseudo-parabolic cross-section. The reflective surface having the parabolic or pseudo-parabolic cross-section defines an optical center comprised of a focal line. The linear light source is disposed with its central axis being substantially coincident with the focal line or optical center of the respective reflectors.

Abstract: A remote sensing system including a control module coupled to a remote device module via an optical fiber is disclosed. The device module includes circuitry for detecting changes in physical parameters and for transmitting data relating thereto back to the control module in serial form via the optical fiber. Power for the circuitry within the device module is obtained from a photodiode which receives light from the control module via the optical fiber and no power multiplication is utilized except which the remote module is transmitting serial data back to the control module. Data signals are also provided from which monitoring of the integrity of the device module and connections thereto can be obtained.

Abstract: An electrophoresis cassette system which when used with a detector can automatically perform an analysis of radio-labelled molecules. The cassette system is easily assembled and may be reused. The cassette includes a new type of side spacer which incorporates nylon monofilament and which includes a buffer zone for increased accuracy. A new clamp and other improvements further enhance the accuracy of the cassette and reduce variations in the electric field at the bottom and sides of the cell to provide increased accuracy. A new cassette filling system is shown for use with the cassette which permits rapid filling of a cassette with gel material while providing a more uniform gel layer than was previously attainable.

Abstract: A spacer for an electrophoresis cassette of the type having front and rear plates, such as glass, with a gel material in the space between the plates in which electrophoresis separation is performed. The cassette includes a spacer between the plates in the form of a thin disk whose thickness is equal to the desired plate separation. A stud projects outwardly from the disk and is received in a hole in one of the plates to locate the stud. Preferably the stud is made of stainless steel.

Abstract: An ovenized oscillator having a temperature sensitive section of an oscillator and a heater supported in a chamber within an enclosure having an insulating gas surrounding the oscillator section and heater. Insulating walls may be added within the chamber to reduce convective heat loss through the gas. These walls form cavities around the oscillator section and are separated from each other except for small vent holes to equilibrate the pressure between cavities.

Abstract: A retainer is provided for holding a printed circuit card between spaced surfaces which comprises a plurality of wedge-shaped members mounted end-to-end on a rod, with at least select ones of those members being each urged in a corresponding transverse direction relating to the adjacent member upon effective shortening of the rod to hold the printed circuit card between the spaced surfaces. A spring is attached to each of the select members to bias those members each in a direction opposite the transverse direction for that member.

Abstract: The output of an alkali vapor lamp for use in an optical pumping system is stabilized by use of a feedback circuit which regulates current flow from a power supply to an electronic power oscillator used to excite the alkali vapor lamp. Starting of the alkali vapor lamp is facilitated by increasing supply current to the oscillator until the alkali vapor lamp is lit.

Abstract: A system for concurrent, non-destructive evaluation of partially completed welds for use in conjunction with an automated welder. The system utilizes real time, automated ultrasonic inspection of a welding operation as the welds are being made by providing a transducer which follows a short distance behind the welding head. Reflected ultrasonic signals are analyzed utilizing computer based digital pattern recognition techniques to discriminate between good and flawed welds on a pass by pass basis. The system also distinguishes between types of weld flaws.

Abstract: A radiation source directs light at a mirror which reflects to a first photosensor. As a dew point is reached, scattered light is reflected to a second photosensor to indicate dew point. Rather than periodically interrupting operation to test reflectivity of the mirror or to perform a heating cycle, operation is monitored continuously. The common mode output of both the first and second photosensors is monitored. When below a threshold level, the output indicates the need for cleaning the mirror. It may also be used in a closed loop to increase light source intensity as mirror reflectivity decreases.

Abstract: An optical-physics package used in an atomic frequency standard is miniaturized and the performance thereof improved. The optical-physics package includes a microwave cavity in which is positioned a filter cell and an absorption cell, preferably located in close physical proximity to one another. The microwave cavity may double as an oven, and is preferably designed to operate in the TE111 mode with "E" probe microwave coupling. Dielectric loading is provided by the filter cell and absorption cell to reduce the internal dimensions of the microwave cavity.

Abstract: A method and apparatus for determining lane count error in a conventional navigational system which gives the position of a vessel in an integer and fractional lane count format but has an inherent integer lane count ambiguity. A second navigational system capable of determining the distance between the vessel and a surveyed transponder or other fixed element is placed on board the vessel. Readings are taken from both the conventional and the second navigational system at at least two separate positions of the vessel. By combining and comparing the data obtained from both systems, an operator can determine the lane count error in the conventional system.

Abstract: A miniaturized vapor discharge lamp assembly that includes a light transmissive bulb containing a buffer gas and a vaporizable light radiating substance such as rubidium. Lamp excitation is provided by the use of a capacitor in the lamp assembly in conjunction with an RF oscillator. The capacitor establishes a substantially longitudinal electric field which ionizes the rubidium vapor to cause emission of light. The need for an RF excitation coil is eliminated.

Abstract: Methods and apparatus for rapidly and automatically syntonizing the frequency of a passive atomic resonator of an atomic clock with a reference frequency which corresponds to the frequency of an external reference signal. Any difference between the hyperfine transition frequency of the resonator and the reference frequency generates an error signal which is used as a basis for automatically determining the magnitude of a quantity which adjusts the actual hyperfine transition frequency of the resonator.

Abstract: A method and apparatus for producing a linear plan view display of a seabed, employing a side scan sonar signal system, have circuitry for repeatedly determining the height of the transmitting source relative to the seabed, circuitry for sampling the returning sonar signals, and circuitry for providing from the height determination and the sampled signals, the slant range correction needed to provide a linear output display, at least in a direction normal to the direction of movement of the transmitting source. The preferred method and apparatus also have elements for determining the velocity of the transmitting source and for effecting a one-to-one aspect ratio linear plan view of the seabed topography. In other aspects of the invention, a method and apparatus for controlling the display and for implementing the mapping transformation are described.

Abstract: A dew point hygrometer wherein separate reflective surfaces reflect light from separate light sources to a single light sensor. One surface is cooled to develop a coating of condensation. The other surface provides a standard to detect contamination build-up on both surfaces, and to detect variations in the operation of the single light sensor.

Abstract: A dew point hygrometer which employs two cooled reflective surfaces with one surface being held at a lower temperature than the other. The lower temperature surface provides a wet mirror to detect dew formation and the dry mirror provides a standard which may be used to compensate for contamination build up on both surfaces.