Abstract: A circuit for operating an electric discharge lamp wherein a change in the mode of operation of the circuit is effected in response to a change of phase of a voltage or current in the circuit which occurs during operation e.g. when the lamp strikes or as the lamp runs up to full current.

Abstract: A discoidal armature for dynamoelectric machines has its winding conductors bonded together in a rigid structure by means of a resinous material, and its commutator bonded to the structure. The structure has a disc portion containing the coil sides and outer and inner ring portions containing the coil end-heads and other end connections. The coils have their sides and end-heads of shapes which permit them to nest closely together in an annular array of overlapping coils. They are stranded and have the strands in their side arranged to provide a tapered disc portion which is thicker at the inner ring portion than it is at the outer ring portion. The commutator consists of an annular array of segments bonded to the disc portion adjacent the outer ring portion and presents a working face on the side of the disc portion. A similar array of segments can be bonded to the other side of the disc portion to obtain a duplex commutator.

Abstract: The printing elements of a tape printer of the "dot matrix" type are provided by ends of a stack of metal strips which co-operate with an anvil having a rectilinear edge. The anvil is carried by a member which is pivoted on a support structure and is held in its working position by engagement with a tray carrying a spool of tape to be printed in a manner that provides a resilient mounting for the anvil. For the purpose of fitting a replacement spool of tape, the tray is movable from its working position to another position in which such fitting is more easily effected.

Abstract: In a loudspeaking telephone arrangement using voice switching a closed-loop circuit is used to apply an averaged rectified ambient-noise signal to the comparator from one or both channels to enable proper voice switching regardless of ambient noise levels or line length.

Abstract: According to the invention electrically conductive paths are provided between the coil armor and the core laminations of dynamoelectric machines by placing a semiconducting elastomeric material between the coil sides and the walls of the core slots. The elastomeric material is of a type which has a controlled resistance and will deform sufficiently under pressure to flow into the irregularities between the coil side and the slot walls, and in so doing provide conductive paths for electric charge to flow from the armor to the core laminations. This material must be capable of retaining its strength, elasticity, conductivity, etc., and remaining in place between the coils and core under vibration, coolant flow, electric stresses, repeated temperature changes, etc., for the operating life of the machine. Preferably, these paths will be heat conductors as well.

Abstract: A current sensor provides a voltage signal which is proportional to the average current flowing through a semiconductor device junction. This voltage signal is applied to a first analogue circuit which produces an output voltage indicative of the average power dissipated at the junction. The output of the first analogue circuit is applied to a second analogue circuit which outputs a voltage signal indicative of the temperature difference between the junction and a heat sink associated with the semiconductor device and to a third analogue circuit which outputs a voltage signal indicative of the temperature difference between the heat sink and ambient. The ambient temperature is sensed by an ambient temperature sensor which outputs a voltage signal indicative of the ambient temperature. A voltage summing circuit sums the output voltages from the second and third analogue circuits and from the ambient temperature sensor, and produces an output voltage indicative of the junction temperature.

Abstract: An axial gap synchronous dynamoelectric machine consists essentially of a disc-shaped rotor having axially oriented permanent magnet pole bodies with faces lying in an annular surface; a stator core spaced axially from the pole faces; and a discoidal AC winding linked with the pole bodies and the core. The winding consists of a plurality of coils laid overlapping in an annular array and bonded together with a resinous material into a unitary structure having an annular disc portion containing the coil sides and inner and outer ring portions containing the coil end-heads. It is supported by the stator with its disc portion in the space between the stator core and the pole faces, and its disc portion is spaced axially from the pole faces.

Abstract: A traffic signal housing particularly suitable for moulding modular units frm engineering thermoplastics. The back body portion is generally cylindrical; each end portion of the cylinder is reinforced with radial webbing connecting to a coaxial inner cylinder, thus forming a stiff load transfer structure extending into the housing to a depth of about 10 percent. The peripheral edges of a one load transfer structure are shaped to mate and seal with those of an adjacent unit. Units are coupled with a pipe bolt passing through adjacent inner cylinders to place the reinforced ends under compression. Thus assembled units have a great rigidity and load may be transmitted without the undue flexing or cracking common in prior known units.

Abstract: A television transmission system of the kind in which some of the line scan periods of a conventional transmission that are left blank (as far as picture content is concerned) between successive frame transmissions are utilized for signalling data for selective display on the screen of a television receiver. The improvement over previous systems is that the information to be displayed as a line of data may be transmitted in a single line scan period. This is achieved by transmitting in a line scan period a page number and then in subsequent line scan periods the lines of data for that page. New page numbers are then transmitted followed by their respective lines of data in sequence. A receiver for the transmission system is described.

Abstract: A receiver for a television transmission system of the kind in which some of the line scan periods of a conventional transmission that are left blank (as far as picture content is concerned) between successive frame transmissions are utilized for signalling data for selective display on the screen of a television receiver. The information to be displayed as a line of data may be transmitted in a single line scan period. This is achieved by transmitting in a line scan period a page number and then in subsequent line scan periods the lines of data for that page. New page numbers are then transmitted followed by their respective lines of data in sequence. The receiver selects a desired page of data by identifying the desired transmitted page number and then recording all lines of information subsequent to that page number until it identifies a further page number whereupon it ceases to store any further information.

Abstract: A demodulator for a digital code differential phase shift modulated signal comprising: an input transducer for launching surface acoustic waves corresponding to a received modulated signal; a plurality of output transducers each of which is arranged to produce an output signal dependent on the relative phases of a number of successive code elements of said surface acoustic waves, each output transducer producing a larger output signal, in a predetermined sense, than any other output transducer when said successive elements have a particular phase relation, different for each output transducer; and means responsive to the relative magnitudes of the outputs of said output transducers.

Abstract: A method for removing an impurity from a liquid metal in which: a flow of the liquid metal containing the impurity is passed into a chamber containing a quantity of the liquid metal and an electrolyte in which the impurity dissociates to form positive and negative ions; a voltage is applied between a pair of electrodes disposed respectively in the electrolyte and liquid metal to effect electrolytic extraction of the ions from the electrolyte; a flow of liquid metal is extracted from the chamber for circulation through an associated equipment; and an appreciable quantity of the electrolyte is circulated with the extracted liquid metal.

Abstract: An electric tank heater for heating the engine coolant system of an automotive vehicle comprises a tubular tank shell having an open end in which is secured an annulus having a U-shaped wall. The outer leg of the annulus is circumferentially secured and sealed the shell. The inner leg extends inwardly through the end of the shell and is spaced from the inner surface thereof. A removable closure plug member from which an electric immersion heating element depends for projection into the shell is inserted into the annulus and seals against the inner leg thereof with an O-ring seal. The closure plug member is retained in place by a yoke engaging the edge of inner leg.

Abstract: An electrical filter for extracting from an applied input signal a pseudo-random sequence signal contained in the input signal comprises: an analogue delay line; means for applying to the input of the delay line an input signal containing the pseudo-random sequence signal; feedback means for producing a feedback signal in response to the signals appearing at two or more points along the length of the delay line; and combining means for combining said feedback signal with said input signal; said feedback means being constructed in dependence on said pseudo-random sequence so that, at the input of the delay line, said pseudo-random signal in said input signal is reinforced by said feedback signal.

Abstract: A pushbutton telephone semiconductor dialling circuit power supply comprising a capacitor fed by a diode bridge placed in series with the line looping circuit during dialling. The capacitor size is chosen to charge to at least minimum circuit supply voltage during make periods of line looping, and to keep the circuit supplied during break periods. A constant current charging circuit may be employed to charge the capacitor from the bridge to improve performance, with a diode to power the circuit directly from the bridge while the capacitor is still charging.The microphone-bridging off-normal contacts may be replaced by a transistor switching circuit.

Abstract: A data signalling system in which binary `0` is transmitted as `01` and binary `1` is transmitted alternately as `00` or `11`. This code gives good timing information for use at the receiving terminal of the system regardless of the data actually being signalled. Negative transitions of the transmitted waveform (i.e. from `1` to `0`) occur only at the ends of data bits periods and such transitions are utilised at the receiving terminal to synchronise a clock pulse generator which controls the operation of decoding apparatus at that terminal.

Abstract: A repertory dialler has a main digital data store for the storage of information required for impulsing to line upon operation of a selected call push-button. This store is a circulating dynamic store. The dialler may be operated either in a recording mode or in an impulsing mode as determined by the position of a manually-operable switch.In the recording mode, the identity of a call push-button that has been operated is first written in digital form into a circulating buffer store. This is followed by the decimal digits of the exchange and/or directory number of a subscriber which are entered by means of a digit keypad. When all the required digits have been so stored, the data temporarily stored by the buffer store is transferred to the main store and in the main store is added to the end of the block of data circulating therein.

Abstract: A core for a nuclear reactor of high specific power output is provided with an arrangement of fuel bundles in which at least some bundles incorporate tubular pencil elements mounted between end plates, having coolant flow restricting means secured to the bundle to control the balance of coolant flow between external flow along the outsides of the pencils and internal coolant flow within the hollow pencils.