Abstract: A clasp or catch for jewelry items or the like, comprises: a first member, for attachment to one end of a jewelry item, having two parallel sides and two transversal bars interconnecting the two sides; a second generally O-shaped but not closed member having one end pivoting around one of the two transversal bars, and the other end securely engaging the other of the two transversal bars; and a third member, for attachment to another end of the jewelry item, similar in construction to said first member, having at least one cross bar for retaining said other end of the second member when not engaged by said other of the two transversal bars.

Abstract: A magnetic bubble memory based floppy disk emulating system is provided which is capable of emulating available industry standard floppy disk drives with a simple, microprocessor controlled system in which direct memory access techniques are used to free the microprocessor to perform the control functions necessary to emulate single/double density and floppy/minifloppy disks.

Abstract: A simple but versatile communication switching system suitable for air traffic control and the like applications is provided. The system utilizes a central pulse amplitude modulation bus, is modular in structure, and provides the time division multiplexed representations of the auxiliary circuit terminations, such as radio and trunk circuits, on the central bus for direct access by all modules.

Abstract: An electronic circuit module and a compatible module holder are provided which are particularly suitable for magnetic bubble memory applications. The holder has power-down warning and write-protect circuits utilizing light emitting diodes (LEDs) and photo-transistors to detect motion prior to removal of the module, and to detect the presence of a reflective sticker to write enable, respectively. Moreover, the module has separate ground buses for each power supply voltage to prevent circuit damage due to relative polarity reversal in case of ground non-connection upon insertion or removal of the module from the holder.

Abstract: An improved circuit for synchronizing signal recovery particularly suitable for mobile radiotelephone operation is disclosed. The initializing circuit of the phase-locked loop in the data receiver is inhibited for a predetermined duration upon triggering of a "window mode" by either of a rising or falling pulse-edge in a sequence of "ones" or "zeros" in the received data. The window mode masks the invalid transitions in such sequences and prevents retriggering by such transitions.

Abstract: A telephone answering system is disclosed capable of accommodating geographically dispersed customer stations and obviating the need for any dedicated concentrators or distributors. The TAS bureau comprises a plurality of stations each having access to two telephone lines, with the whole bureau having a single access number. The customer station has full control over the mode of service desired at any given time, and a modem in the customer station communicates necessary information as needed to its counterpart in the TAS station.

Abstract: A receive circuit for binary signals in time compression multiplexing systems mitigates effects of the local data decay tail and zero line wander by means of a sample-and-hold circuit, having a fast attack and a decay time constant equal to a combination of the transmission line, and dc blocking device time constants followed by a subtracting difference amplifier. Power feed of the line via dc blocking capacitors is thus possible. Also higher receiver gain is possible when sampling switch is left on during local data transmission without receiver instability.

Abstract: Method and apparatus are provided for mitigating the effects of temporal filtering in a transmitted DPCM encoded video signal wherein the signal is conditioned in the receiver by the inverse temporal filtering function without the disadvantageous use of video frame memory.

Abstract: A stove for burning solid fuels such as wood and coal with improved efficiency has three generally distinct combustion zones namely a primary zone, a secondary zone and a tertiary zone, thus ensuring fuller combustion of residual combustible gases in the tertiary zone just after the primary flue exit. The novel tertiary zone is situated only at the lower portion of the base of the flue gas exit chamber, is encased by firebrick and is fed only with combustible gases from the primary zone.

Abstract: An analog signal is sampled in response to a sampling command. Each time that the analog signal, or the difference between the analog signal and the previous sample thereof, crosses a respective reference level, a digital signal is produced. Each digital signal consists of a code representing the level crossing or incremental change in level which has occurred and a count representing the time which has elapsed since the last sample command. A digital signal is also produced if the elapsed time reaches a predetermined period. On production of each digital signal, a sampling command is produced and the elapsed time counting is recommenced. The digital signals constitute a digital representation of the analog signal. The converter is particularly useful for converting analog signals having both very high and very low frequency portions, such as current surges which occur on telephone lines affected by lightning (high frequency) and 60 Hz induction (low frequency).

Abstract: A modular system for interconnecting multiple insulated wires contained in a plurality of cables includes as basic elements: a module having a channel-like base member, two support members one each side of the channel for releasably supporting a plurality of connector blocks thereacross, a plurality of designation strips supported between said conductor blocks between said support members and split distribution rings for guiding cables and wires and acting as spacers between modules.

Abstract: A device for organizing optical fibers and the like at splice or slack points is provided. The device comprises a plurality of stacked tray-like supports having partially turned-up edges, with each separately hinged at one side thereof to a carrier. Each tray-like support is adapted to retain a looped fiber portion without damage by having a width at least equal to twice the minimum bending radius specified for that fiber.

Abstract: An apparatus as disclosed for displaying a stored single frame NTSC color video signal on a TV monitor comprising a delay line for delaying every alternate retrieved frame by one-half the color sub-carrier period prior to their application to the monitor.

Abstract: The present invention provides a pulse amplitude modulation sampling gate using inexpensive integrated devices having a novel feedback arrangement. The addition of a few passive components to the basic sampling gate allows the gate to coact as a three pole high pass filter. Costs are reduced by this approach by a large factor.

Abstract: A terminal post is provided, for terminating buried cable, made of extruded aluminum and providing full access to the connector blocks housed inside by means of fully removable cover and a doubly hinged panel.

Abstract: An improved negative impedance converter is provided comprising an additional differential operational amplifier to improve signal handling capability.

Abstract: A method for substituting one memory module for another, faulty, memory module comprises designating and marking a memory module as the substitute module, which, upon detection of a fault in the other memory module, is inhibited from responding to its own address when called, and responds to the address of the faulty module whenever the latter is called.

Abstract: During encoding of voice frequency (VF) signal in a PCM channel bank the encoder encounters direct current (d-c) offset component resulting from the particular VF signal. Such d-c offsets cause errors above and beyond the normal errors inherent in the normal encoding process. The present invention alleviates this problem by providing an automatic d-c offset cancellation circuit which closely follows the d-c offset component and provides a d-c component of opposite sign to cancel it.

Abstract: A novel photodetector circuit utilizing both the generated photovoltage, as well as its inverse, to improve the signal-to-noise ratio at the optical receiver output.