Abstract: A three input Exclusive OR-NOR gate circuit. The circuit comprises inverters for receiving three input signals and for providing three inverted input signals, a power potential terminal, a reference potential terminal, and an Exclusive NOR output node and an Exclusive OR output node. The circuit also includes transistors of a first conductivity type responsive to the signals on the output nodes for connecting the power potential terminal solely to one of the output nodes, and transistors of a second conductivity type responsive to the input and inverted input signals for connecting the reference potential terminal solely to the other of the output nodes.

Abstract: A converter device for converting signals between an RS-232 device and an RS-422 device. The converter device can either be self-powered, using signals at the I/O port of the RS-232 device to derive its operating voltages, or can be powered by an external voltage source when the I/O signals are not of sufficient magnitude to derive the operating voltages or there are a large number of devices connected in parallel by the converter device.

Abstract: A simple and reliable liquid level control for controlling the level of a cryogenic fluid within an enclosure for an electrical component. This totally mechanical system varies the flow rate of the cryogenic fluid from a supply conduit until the full level is attained at which point the flow is completely turned off. Details of materials used and construction considerations made in order to operate in this somewhat unstable environment are presented. The design includes the passages for exhausting the evaporated cryogenic fluid that is boiled off by the heat from the electrical component in the enclosure.

Abstract: A heat sink for conducting heat from an electronic device is disclosed. The device has a mounting base and two U-shaped members. Each U-shaped member has first and second walls integral with a top ridge. The first wall is integral with the base and extends away from the base and the second wall has a terminus portion proximate the first wall. Each U-shaped member is adapted to retain an electronic device between the first wall and the terminus portion.

Abstract: A digitally controlled timing circuit for providing an output pulse signal precisely delayed with respect to an input signal irrespective of the time of occurrence of a system clock, but which uses the precision of the system clock to self-correct any inaccuracy in the delay includes a plurality of delay elements, the delay period of a respective one of which is adjustable, coupled between an input terminal, to which an input terminal is applied, and an output terminal, from which a delayed output signal is to be derived. Coupled to the input terminal and the plurality of delay elements is a toggled flip-flop which, with the delay elements, during a calibrate mode, forms an adjustable oscillator and generates a sequence of signals the lapse of time between successive ones of which is established by delays imparted by selected ones of the delay elements. The delays imparted by selected ones of the delay elements.

Abstract: The subject invention is a separation device for first and second generally parallel printed circuit boards connectable by a plurality of pins projecting normally thereto. The separation device comprises a first member attachable to the first board and having a hole extending laterally therethrough. The device also comprises a second member having a shaft mateable with the hole, an eccentric body, and means for rotating the second member. When rotated, the eccentric body provides a separation force on the boards.

Abstract: A tool for inserting and removing a component, such as a programmable gate array integrated circuit (PGA IC) chip. At least two blocks are mounted on a threaded rotatable shaft, the shaft for causing relative movement between the blocks when rotated. Resilient flanges which are biased outward are attached at one of their ends to the uppermost block, while rigid support flanges are attached to a lower block. The free ends of the resilient flanges contain catches for gripping a PGA IC or its socket (mounted on a printed circuit board, e.g.). For removal of the chip, the catches grip the IC, and the shaft is rotated to cause the IC to be pulled from the socket. For insertion, the catches grip the socket, and shaft rotation causes the lowest block to push the IC into the socket.

Abstract: A simple, yet fluid tight seal for a cryogenic enclosure. The seal between two portions of the enclosure becomes tighter as the temperature is lowered because both portions contract against a third member which does not contract with temperature to the same degree. Further, this contraction is elastic and therefore the enclosure may be disassembled and reassembled numerous times without damage to the seal. This is particularly advantageous for sealing lids or containers for cryogenic electronic components.

Abstract: The subject invention is an apparatus and method for cooling an electronic device. The apparatus comprises a vessel having upper and lower regions and inlet means for delivering a flow of cooling fluid to the upper region. The apparatus also includes means for positioning the device within the lower region but above the bottom of the vessel, and divider means within the vessel disposed between the flow and the device.

Abstract: A power supply for producing a single level D.C. output voltage in response to a 110 or 220 A.C. input voltage is disclosed. The power supply automatically selects a full wave diode bridge or voltage doubler configuration and provides series capacitors to filter the D.C. output voltage. The selection is controlled by a switch which responds to the charge on one of the output capacitors. Latching means are also provided to prevent the power supply from switching to the voltage doubler configuration once 220 volts is applied.

Abstract: A data process system has a plurality of stations or terminals linked to a star coupler over cables comprising separate sending and receiving transmission lines, the cable shield being connected to system ground. To minimize bit error rate when a station is powered down, the transmitting differential amplifier at each terminal station is connected between a bias voltage and a virtual ground created by a pair of diodes connected in parallel, their anodes being connected to a voltage source through a current limiting resistor, the cathode of one diode being connected to system ground, the cathode of the other diode being connected to one side of the transmitting amplifier to define the virtual ground. To further enhance noise rejection, a balanced differential network is connected to the outputs of a transistor pair at the amplifier output to the differential wire transmission line.

Abstract: A pump and method for delivering a cooling fluid from a reservoir of fluid to a destination is disclosed. The pump comprises a vessel for holding fluid to be delivered, the vessel being submersible within the reservoir. The vessel has a fluid inlet near its bottom for receiving fluid from the reservoir and a gas discharge outlet near its top. The pump has an inlet valve for preventing fluid from flowing out of the vessel through the fluid inlet, and a gas discharge valve for opening and closing the gas discharge outlet. The discharge valve is responsive to the level of fluid within the vessel. The pump also comprises a conduit for conducting fluid from inside the vessel to its destination, and heating means for evaporating the fluid within the vessel. This heating creates a pressure head within the vessel when the gas discharge outlet is closed thereby causing the fluid to flow through the conduit.

Abstract: A fluid level controller having a thermal expansion element in the form of cylinder made from polytetrafluoroethylene. The cylinder is located in a container which is connected to a supply of cryogenic fluid by a ball valve. When the cryogenic fluid in the container reaches the level of the cylinder and cools it, the cylinder shrinks and causes a lever to close the ball valve. When the cryogenic fluid falls below the level of the cylinder, the cylinder expands and the lever opens the ball valve and permits cryogenic fluid to flow through the valve and into the container. The cylinder has a heating element disposed in its interior to hasten the response of the cylinder to a change in the fluid level.

Abstract: The subject invention is a power supply having an input for receiving a power signal, a DC storage device connected to the input, a primary output connected to the DC storage device and connectable to a battery, a DC to DC converter for converting the voltage at the DC storage device to an auxiliary DC voltage, the converter having a supply voltage input, and a switching circuit. The switching circuit includes first, second and third switches. The first switch is responsive to the power signal for providing the DC storage device voltage to the converter supply voltage input. The second switch is responsive to the voltage on the battery for providing the DC storage device voltage to the converter supply voltage input. The third switch is responsive to an auxiliary voltage on/off signal for overriding the second swtich.

Abstract: Line broadening is eliminated in dry heat-developed films by using a development temperature which is higher than the manufacturer-recommended standard temperature, so that a much shorter development time can be used, and masking the edges of the film to prevent exposure thereof. The hot/short development cycle and the masking of the film edges substantially eliminate image smearing caused by emulsion shrinkage and migration.

Abstract: A MOS circuit for trimming a digital pulse signal by delaying the rising edge of the pulse signal for a predetermined period of time and passing the falling edge without delay. The circuit includes two MOS output transistors and a signal buffer. The signal buffer has a number of stages for delaying the pulse signal, with the number chosen to control the delay in the rising edge of the pulse signal. One of the output transistors receives the pulse signal at its drain and is enabled by the delayed pulse signal from the signal buffer to pass the pulse signal after the predetermined period of time to its source at the output of the circuit, so that the rising edge is delayed, but the falling edge is not. The other output transistor is enabled to ground the output of the circuit after the falling edge of the pulse signal. A self-booting circuit drives the gate of the one output transistor to assure that the voltage level of the trimmed signal will not be reduced by dissipation across the transistor.

Abstract: An improved connector for attaching a mother board to a daughter board, having a slotted housing, a slotted elastomeric member, and a flexible circuit with numerous conductors. The flexible circuit is wrapped around the elastomeric member with its two free ends ending at the slot of the elastomeric member. The wrapped elastomeric member is located in a chamber in the housing with the slot in the housing communicating with the slot in the elastomeric member so that when the daughter board is inserted into the housing, it engages the free ends of the flexible circuit within the slot of the elastomeric member. The elastomeric member has two semi-cylindrical portions which are separated by a channel at the bottom thereof. The elastomeric member with these semi-cylindrical portions is slightly larger than the chamber of the housing when mounted by fasteners to the mother board.

Abstract: A double walled vessel having a styrofoam filling between the double walls internally supports a semiconductor circuit to which is attached at least one flat ribbon cable. The semiconductor circuit is immersed in liquid nitrogen with at least one flat ribbon cable extending to the top lip of the vessel. Carbon conductors are connected to each conductor of the flat ribbon cable and extend to the outer wall of the vessel. Another flat ribbon cable is connected to the carbon conductors and to an electrical connector. A double walled top having a styrofoam filling is secured to the vessel such that the carbon conductors are sealed between the styrofoam filling of the top and the double walled vessel thereby preventing the formation of frost on the flat ribbon cable and connector that is external to the sealed vessel. Various tubings are inserted through the double walled vessel to permit the insertion of liquid nitrogen and the drawing off of gaseous nitrogen.

Abstract: A power supply which automatically configures itself to correctly respond to either a low or a high level of an A.C. supply voltage to supply a single level D.C. output voltage. The supply switches between a voltage doubler and a full wave rectifier operation dependent on the level of the A.C. supply voltage. Once the supply switches to the full wave rectifier configuration, a latch prevents the power supply from switching to the voltage doubler configuration until the A.C. supply voltage is removed from the power supply. The latch prevents damage to components by preventing the power supply from switching to a low input voltage configuration when, in fact, a high input voltage is present.

Abstract: A plotter for recording data from a modulated laser beam onto a recording medium mounted covering the aperture of an aperture card wherein the aperture is located toward one end of the aperture card with a blank margin on either side of the aperture, the plotter including an aperture card supply module for supplying the aperture card from a plurality of aperture cards, a carriage module having a recording station and a platen member for stepping the aperture card past the recording station, a laser scanning module for scanning a row of data from the modulated laser beam laterally across the recording medium through the recording station as the recording medium is stepped past the recording station by the platen member, a dry developer module for developing the data recorded on the recording medium by the laser scanning module, a feed path from the aperture card supply module through the carriage module and the dry developer module, and transport apparatus for transporting the aperture card along the feed path