Abstract: A method of making a channel substrate buried heterostructure InP/(In,Ga)(As,P) laser avoids the need to use two separate stages of epitaxial growth by using a channel in a (100) surface substrate 1 extending in the [011] direction with {111}B sides. This allows the channel to be made before the growth of an (In,Ga)(As,P) blocking layer 3 which can be grown under conditions which do not require the use of a mask to prevent nucleation on the channel sides. The same technique is also applicable to the manufacture of a terraced substrate laser incorporating a blocking layer.

Abstract: An associative processor is described wherein an array of associative processing cells is configured to achieve variable length multiplication of numbers, such as binary two's complement numbers, under mask control. A configuration suitable for signal multiplication is described wherein the processing sequences in all cells are compatable, each to the other, whether the cells are at the edges or the middle of an array row, and regardless of the computational sequences required to be performed. An associative cell structure is described, including an improved arithmetic logic unit having separate carry and borrow save paths which may be enabled and active simultaneously or alternately.

Abstract: At least one metallic element is incorporated into a cable during the manufacture of optical fiber cables, along with one or more elongated optical fibers. Such metallic element with its insulation is similar in diameter to an optical fiber with its sheath. The electrical resistance of the metallic element varies very little with temperature, but does vary with strain. Hence, by monitoring the resistance of the metallic element, the strain to which the fibers are subjected can also be monitored.

Abstract: A frequency down-converter down converts an input signal having a frequency in a given bandwidth and a frequency up-converter up converts the down converted input signal and imparts a doppler shift to the up converted signal to generate an output signal having a frequency with doppler shift in the given bandwidth.

Abstract: A soft clipping circuit for a telephone subset limits the output signal amplitude to the line thus preventing output stage saturation with consequent reduction in impedance. The circuit includes a variable gain input stage (I/P), a main speech signal amplifier (AMP1) and a rectifying amplifier feed back stage (AMP2) that generates a control current whenever the output speech signal exceeds a predetermined threshold. This current is fed to the input stage so as to reduce its gain. Typically the input stage comprises a long tailed transistor pair amplifier, the control current being fed to the tail of the pair.

Abstract: A method of synchronizing a digital radio pager receiver with incoming digital data signals. At switch-on the receiver first attains a "course" bit synch during the first quarter-word period and then a "fine" bit synch during the next half-word period. The receiver then examines incoming data bits to determine simultaneously (a) whether valid data is being received and (b) whether the incoming data contains a preamble sequence. If either determination is successful the incoming data is then examined to determine whether it contains a synchronizing word or an address word. The synchronization and address word determination is also carried out while bit synch is obtained and the valid data/preamble determination is effected.

Abstract: A line switch for a digital telephone switching system utilizes distributed processing. The line switch comprises one or more switch modules. Each switch module is coupled to a central office switching system via one or more PCM lines which utilize common channel signaling. Each switch module comprises groups of line circuits, each line circuit being coupled to a subscriber line. Three separate distributed processor functions are provided in each line switch module. A first processor is utilized to communicate with the central office switching system and to coordinate the operations within the line switch module. A second processor is provided to control clock generation and rate conversion circuits. Each group of line circuits includes a third processor to control the operations of the line circuits and to gather information from the line circuit. A busing arrangement is provided within the line switch such that both control information and PCM voice data are routed throughout the line switch.

Abstract: A device for guiding a submersible pump unit to and from its operation position includes an essentially vertical thin guide member the lower end of which gradually changes into a broader portion and the upper end of which is tilted to make possible an easily releasable connection to a guide formed on the pump unit.

Abstract: A relay with a contact making independent from environmental conditions with two hermetically sealed contact pills is described. Each contact pill comprises a switching-over contact and a diaphragm made of electrically and magnetically conducting material which diaphragm is the movable member adhering on corresponding contact poles due to the magnetic flux caused by a permanent magnet and flowing through the core of a drive coil. To change the contact condition of the relay it is sufficient to produce a current pulse through the drive coil causing a control flux of a magnitude which exceeds that of the permanent magnet flux by a small amount only because the two fluxes add their strength when the change-over operation is initiated. Due to this adding the needed drive power is so small that a direct driving by TTL-circuits is possible. By other arrangements of the permanent magnet within the magnetic circuit monostable relays can also be realized.

Abstract: Floor-sweeping machine consisting of a housing with a revolving brush mounted rotatably therein and having pinions which are provided at its two ends and which are themselves each connected operatively by engagement to a pair of running drive wheels, the two running drive wheels belonging to a particular pinion being mounted rotatably in a wheel case and the wheel cases being mounted in appropriate housing receptacles so as to be vertically displaceable for adjusting the height of the revolving brush mounted fixedly in the housing, wherein, for a permanent adjustment of the height of the revolving brush without impairing the drive of the revolving brush by the running wheels, each wheel case (26) is retained by means of a wheel-case holder (38) to swing on one leg (44) of a U-shaped adjusting shackle (45), and the U-shaped adjusting shackle (45) is mounted pivotably in appropriate bearings (55) of the housing (11) by means of angled portions (54), shaped on the free ends of the legs (44), and an adjustable we

Abstract: In the manufacture of optical fiber having a core of a core material and a cladding of a cladding material by drawing the fiber from an optical glass preform, the preform is manufactured by reacting a first plurality of initial reactants in their vapor state to obtan core material particles, by producing a coherent core body from the core material particles, by reacting a second plurality of initial reactants in their vapor state to obtain cladding material particles, by providing a coherent porous cladding on the core body from the cladding material particles, and by sintering the resulting composite body to convert the same into the preform. The core body can either be sintered before combining the same with the porous cladding material, or it may remain in its initial porous state until the sintering of the composite body.

Abstract: Electrical resistance heating element including a number of metal strips arranged in a meander-like pattern. In the resistance metal strips, which are made from a non-expensive base sheet material like lead, there is incorporated at least one fuse which will operate if the heat transfer from a randomly placed area of critical size (a critical area) is substantially blocked. The fuse or fuses are preferably constituted by a lead/tin alloy rolled into intimate contact with the lead base material.

Abstract: A radiation detecting arrangement for measuring or counting an ionizing radiation contains a compensating filter arrangement which safequards a measurement of the radiation dose which is either independent of the energy, or independent of both the energy and the direction thereof. The compensating filter arrangement contains a supporting tube made from a slightly absorbing metal having an ordinal number not higher than about 35, which surrounds a tubular radiation detector and which, on its surface, carries several ring-shaped filter parts. These filter parts are made from one or more metal sleeves of a heavy metal or of a heavy metal alloy slipped onto the supporting tube and soldered or cemented thereto. These filter parts, as regards position and shape, are manufactured by a metal-removing process with only the supporting tube being clamped by the metal-removing machine.

Abstract: A gain regulation circuit e.g. for a telephone subscriber's instrument, includes a plurality (2n+1) of long tailed transistor pairs one of which has a significantly higher gain than the remainder (2n). The circuit may be adjusted to a composite gain value between limits defined by the high and low gain pairs by providing a suitably weighted combination of these pairs. Typically, this weighting is achieved by control currents fed into the tail circuits of the pairs.

Abstract: An electronically tunable narrow band tuned cavity filter includes a housing which bounds a tuned cavity, a plurality of resonator bars secured to the housing, extending across the tuned cavity and having respective extensions that pass through respective openings of the housing to the exterior of the tuned cavity, and a set of tuning capacitor plates for each of the resonator bars. The tuning capacitor plates associated with the respective resonator bar are arranged outside the tuned cavity around the extension in a compartment surrounding the opening, together with respective switching networks driven by an electronic drive and operative for including the capacitor plates in or excluding the same from electric circuit with the respective resonator bar. The capacitor plates may be directly juxtaposed with associated facets of the extension to form respective tuning capacitors therewith.

Abstract: In a repeater for a communication system a continuously running local oscillator (P) injects a pilot tone into the repeater input, ahead of all the non-linear functions. The repeater may include an input amplifier 1, a re-shaping amplifier 2 and an output amplifier 3. The pilot frequency is unique to the repeater and is sufficiently close to the clock frequency in a digital system or the carrier frequency in an analogue system to allow the pilot to pass through all the repeater filters. The pilot effects a small phase modulation of the carrier or clock. Measurement of the amount of phase modulation and also the pilot amplitude at the receiving terminal indicates degradation or failure of the system performance. The pilot frequency is used to identify the repeater.

Abstract: In a fiber optic receiver of the type comprising a photodetector, a preamplifier, a postamplifier and a voltage comparator for quantizing the output to a logic level signal, the improvement comprising symmetrical clamp means interposed between said postamplifier and said voltage comparator.

Abstract: A laundry handling machine for performing both a washing operation and a drying operation includes a blower which directs air over the motor during both the washing and drying operations to cool the motor and additionally directs air over a heating element during the drying operation to provide heated air through the vat. A rotational speed reduction arrangement is provided for controlling the timing of both of the operations. A drying operation timing device is driven by the washing operation timing device. A rinsing device is coupled with a supply conduct for a rinsing liquid and also with a siphon drain tube which has a larger cross-section than the supply conduct.

Abstract: A time division multiplex digital data communication system with reduced band width. The system operates on independent digital signals so they can be multiplexed by encoding the time of transition of the digital data on each channel and transmitting serially the encoded times along with a bit for indicating the direction of transition or state after the transition plus bits for synchronization and/or overhead, as necessary.