Abstract: A power supply circuit for generating true sine wave signals by regulating the average value of the signal, whereby the RMS value of the signal is regulated accordingly. By monitoring the circuit through the load, represented by a monitored voltage value, a feedback network is coupled to a variable resistor in conjunction with other circuitry to maintain a constant voltage ratio to the power transformer assuring a properly shaped wave at a larger or smaller variation.

Abstract: Powder cloud development apparatus for developing latent electrostatic images on an insulating member, such as a photoconductive layer, wherein a cloud of charged developer particles is introduced into the development chamber through a first port in the chamber wall and air is introduced through a second port in the chamber wall opposite said first port. A baffle is positioned above the ports and below the surface of the insulator, the baffle extending between the opposed walls. A development electrode comprising a series of parallel wires, electrically biased in the development area, is connected at each end to a continuous loop drive mechanism, the upper plane of the grid wire being closely spaced from the insulator surface. The wire to wire spacing with respect to wire diameter is sufficiently large to allow the passage of toner therethrough.

Abstract: A data processing system includes a control processor in communication with the various devices comprising the data processing system. Communication between the control processor and the data processing system devices occurs on a separate maintenance and diagnostic bus. The control processor initiates diagnostics stored within several of the data processing system devices. The self-diagnosing devices provide an indication to the control processor of successful completion of the diagnostic stored therein. The device being diagnosed and the control processor operate asynchronously of each other and utilize a register bit to indicate successful completion of the diagnostic test.

Abstract: Improved apparatus for wiring through a wall of a sealed enclosure is disclosed. A printed circuit board is mounted on and extends through a slot in the wall, said board etched so that a plurality of conducting lines are provided from inside to outside the enclosure. Standard printed circuit board connectors are mounted on and soldered to the board providing convenient means for the attachment of cables to the board. Finally, the slot space between the printed circuit board and the wall is sealed with a rubber grommet to complete the sealing of the enclosure.

Abstract: A process for manufacturing printed circuit boards wherein a layer of Nickel is plated atop a layer of copper in a pattern corresponding to a desired circuit configuration. The Nickel is used as an etch resist to remove copper from the board in the non-conductive areas. Subsequently, the Nickel is chemically activated such that it will accept a coating of solder particularly at the connection points and in the through-holes.

Abstract: A laser structure for generating white laser light when energized by a source of dc voltage. The laser tube structure comprises a gas-filled envelope having a longitudinal axis, an anode electrode forming a portion of the envelope. A hollow cathode is positioned within the envelope and coaxially disposed with respect to the anode electrode portion of the envelope. Members are coaxially aligned with the ends of the envelope such that a structure is provided for confining a gaseous medium therein, a dc voltage applied between the cathode and anode electrode creating a discharge therebetween, the discharge stimulating continuous wave laser emission along the longitudinal axis of the cathode, the laser emission comprising simultaneous multi-line emissions in the form of white light.

Abstract: A holding device for holding a printed circuit board or other flat plate-like article having a supporting body and a pair of legs extending therefrom to which the article is attached. The attaching means comprises, on each leg, a transverse groove and a notch forming two lips, the outwardly disposed lip having a pin thereon which extends through the article to be supported.

Abstract: During the reading of certain combinations of bits from a magnetic disk memory surface, wider than normal separations may occur between positive and negative peaks. In order to eliminate false peak readings to be decoded by the decoding circuitry, a delayed readback signal is compared with the undelayed signal in a pair of polarity discriminators. The delayed signal is also differentiated to provide a complementary output. Zero crossing detectors are connected to receive the complementary outputs and are gated by the polarity discriminators. The output of the detectors is connected to a latch circuit which sets and resets according to zero crossing detections. An output circuit develops a peak indicating pulse whenever the latch changes state, which is utilized by subsequent circuitry to generate the decoded digital signal.

Abstract: A light focus sensor having first and second grids comprised of interlaced light transmissive and light reflective portions and a rotating optical modulator comprised of a plurality of alternate light transparent and light opaque portions. The modulator portions are half the size of the reflective portions of the grids and the modulator is positioned in relation to the grids such that the phase relationship between the portions of one grid and the portions of the modulator is 180.degree. different than the phase relationship between the portions of the other grid and the portions of the modulator such that the composite signal passing through the modulator is indicative of the directional movement required to achieve focus.

Abstract: A scanning system is provided which uses directed light from a scanning element, which directed light is reflected from a curved reflective surface for scanning across a medium with a planar object surface. The scanning element includes a planar reflective facet, such as the planar mirrored surface of a galvanometer, which scans the light across the curved reflective surface in a direction normal to its axis of curvature. To provide a linear focal line, the planar surface is tilted from its optical axis by a first angle and is off-set for rotation about an axis at a second angle from an optical axis orthogonal to the optical axis of the curved surface.

Abstract: Method and apparatus for moving a plurality of transducer heads to and from an operative position adjacent the magnetic surfaces of a plurality of rotating disks in a magnetic disk storage system. The transducer heads are supported on a "T" Bar attached to a carriage. The transducer heads are loaded or urged towards their respective disk surfaces in pairs of one up (left) and one down (right) or one down (left) and one up (right) by means of a torsion bar. A like plurality of camming elements are mechanically linked with the carriage and are movable radially with the elongated supports to restrain the heads from contact with the disk surfaces until a loading position is reached substantially inward of the circumferences of the disks, after which the camming elements are moved to a withdrawn position and held there by a solenoid-operated latch, thereby allowing the transducer heads to be moved to any desired radial position.

Abstract: Apparatus is provided for automatic production testing of large digital circuit modules. A test station, under computer control, applies test bit patterns and clock pulses to the module under test, analyzes the resultant outputs, and isolates any fault found to one or several IC's. The test station contains power supplies and air cooling for the module, and a keyboard display and printer for use by the test operator. Test programs are developed off-line and are loaded from magnetic tape into a disk pack where they are available to the computer. The flip-flops on the module to be tested are used as an extension of the test station through the addition on the module of circuitry to allow the flip-flops to be reconfigured from their normal circuit configuration into a shift register connected at one end to one of the module connector pins.

Abstract: To eliminate reflections and oscillations when a low impedance level circuit is to be connected to a high impedance level circuit on a printed circuit board, a microstrip/stripline impedance transformer is inserted in between. This transformer is passive and bi-directional, i.e., it can be step-up or step-down. It is made of a continuous folded microstrip (also called a surface etched line) or a continuous folded stripline (also called a buried etched line) wherein each folded section is run in parallel with its preceding one. Because of the mutual coupling between each section with its preceding one, the line impedance of each section will be step-up or step-down depending on the impedance levels at both ends of the interconnection.

Abstract: A concave web guide is disclosed wherein the direction of motion of a web may be changed by a concave web guide which contacts the convex surface of the web. This contact is maintained through the use of a vacuum supplied through spaces in the web guide surface. To minimize contact, air under high pressure emanates from small holes in the guide surface creating an air bearing. This concave web guide may be used in a single capstan symmetrical web feeding system wherein all elements contact the same surface of the web and is particularly applicable to magnetic tape drive systems.

Abstract: This digital circuit generates a window during which the data bit transitions of phase encoded data may be read from magnetic tape. This circuit contemplates a system for reading nine track tape and comprises one phase lock loop and window generator for each track, and the logic and control circuitry necessary to deskew and output the data in the form of nine bit bytes. Each phase lock loop is individually free to correct itself to conform to the variations of its own track, and the control circuit can compensate for a total skew of up to four bit times.

Abstract: Disclosed are methods and apparatus for multi-way program branching in a digital computer based on the contents of a data register. This is accomplished by loading any data field of interest into a data register and using the output lines as address lines to a plurality of read-only memory devices. Each device contains a set of random memory addresses. Logic circuits under program control select and enable one device, thereby producing one address. Finally, circuits under program control force a program branch to the location address produced. Thus, by programming the read-only memory devices and the computer appropriately, a plurality of sets of data fields are associated with and result in branches to a plurality of sets of locations, thereby giving the programmer the general capability of branching to any one of the plurality of locations within one instruction execution cycle based on the interrogation of any one data word.

Abstract: Radiation transmitting apparatus which is smaller, lighter and less expensive than prior art systems, provides approximately 360.degree. azimuthal coverage and has the capability of operating in an infrared countermeasure mode when in a hostile area and as a collision avoidance beacon when in a non-hostile area. In particular, a rotatable reflector is positioned adjacent a fixed infrared source within a protective member capable of being mounted to an object to be protected, such as a helicopter. In the infrared countermeasure mode of operation, the reflector is rotated at a first angular velocity. An infrared filter is positioned relative to the infrared source and the rotating reflector whereby only infrared radiation is transmitted through the protective member.

Abstract: A simple optical correlation system for preventing unauthorized copying of selected documents wherein documents (and copy paper) comprise paper having coded information thereon (visible or invisible) which is optically correlated with a protection device within a copying machine. When light emanating from the copying machine light source is directed to the document, light transmitted from the coded area of the document, which may comprise the entire page area, is sensed by optical detectors within the machine. A reference pattern is positioned between the document and the optical detectors. When the document code and the reference pattern are correlated, the output signal from the reference document is detected and coupled to appropriate circuitry wherein the copying machine is allowed to initiate a copying sequence. If the code on the document and the pattern on the reference document are not correlated, the copying machine is inhibited from operation.

Abstract: Method and apparatus for dynamically braking a multiphase motor wherein, in a first embodiment, the stator windings of the motor are connected in a six winding delta configuration and direct braking current is applied between two center taps of the configuration. A damping diode is connected across two of the delta center taps to minimize voltage transients in the windings when the direct current is removed.In a second embodiment, the stator windings are connected in a twisted Y--Y configuration, the connections to the neutral points of the two Y's of one phase winding set being interchanged and direct braking current being introduced between the two neutral points. A damping diode is connected between the center points of each Y to minimize voltage transients in the windings when the direct current is removed.

Abstract: Apparatus for the automatic inspecting, programming and testing of programmable read-only memory (PROM) devices. Under computer control, this PROM Handling System will test a sequence of PROMs against new part specifications, program them in any sequence of bit patterns required by the next piece of machinery on the assembly line, mark the PROM with a four digit part number identifying the bit pattern contained therein, dry the ink in a heated chamber for a fixed amount of time, dynamically test each PROM bit for access time in a hot and cold environment, program and test replacement PROMs for the ones that had failed at any point in the process, sort the PROMs into the correct order as required by the next assembly line machine and output said tested and ordered parts into output sticks for manual delivery or automatically deliver them by a track arrangement to the next machine.