Abstract: A gas valve which has provision for a reverse flow pulse of high pressure gas. The valve includes a reservoir which is loaded with high pressure gas during normal operation which is released into the main flow path by an applied pressure reduction. The valve is fitted to a porous ceramic "candle" filter between dirty and clean gas zones. The high pressure gas pulse reverses flow through the filter and blows off any aggregated dirt. A shut-off valve is arranged to shut the valve in the event the ceramic filter breaks. The valve is efficient and uses only a metered amount of high pressure gas with little loss of pressure between supply and flushing.

Abstract: A Contact Smart Card (3) is inserted in a contact card reader and its capacitance is measured by applying a square wave generated by an oscillator (1) to it via a resistor (4). The capacitance effect of the smart card (3) affects the amplitude of the output from the resistor (1) and the output is monitored in an amplitude detector (2) connected to receive the signal output from the resistor (4) and to compare it against a threshold level for the signal previously established and stored for an acceptable card.

Abstract: An optical controller is capable of surrounding a player with a radiation screen from a plurality of panels, and enables the player to produce control signals for interface with a controlled instrument such as a musical instrument, a video game processor, etc. The insertion of the appendage of the player can produce a functional control signal. The relative position of the insertion of the appendage can be determined, for example, as a result of the intensity of the reflected radiation in the dispersing radiation screen and adjusted in elevation. The video game processing unit can play either a conventional video game that usually accepts eight functional control signals, or it can utilize the full capacities of the control signals available from the optical controller for enhanced play action.

Abstract: The drive speed of a drive shaft of a screwdriver is selectable by a user by holding a gear transmission housing. Two sets of pinch rollers are employed to rotate the drive shaft at one speed. When the housing is held, one set of pinch rollers is disengaged from the drive shaft, while the other set is engaged through a step-up gear transmission to rotate the drive speed at a greater speed.

Abstract: A meter reading arrangement has an optical fiber transmission path made up of a pair of optical fibers connecting between a meter to be read and a meter interface unit. Light is transmitted over one of the fibers to an indicator on the meter and reflected light is transmitted by the second fiber to a transducer in the interface unit.

Abstract: A method of testing the electrical conductivity of a connection between an integrated circuit device (9) and a circuit board (7) to which the device (9) is connected. The device (9) includes a current path between a further connection (13) thereto and the connection (15) to be tested. The method comprises the steps of, while the circuit is inoperative: applying via the board (8) a potential of a first amount to the further connection (13); applying via the board (7) a potential of a second different amount to the connection (15) being tested; and positioning a probe adjacent the device (9) to sense indirectly current in the current path, the presence of current indicating that the connection (15) being tested is conductive.

Abstract: There is a demand for user access to ISDN services at the two-wire interface point. The frequently raised objection to such access is the problem of determining the location of a fault and hence the responsibility for the fault. This is solved by the use of a voltage sensor responsive to a DC voltage less than a normal line feed voltage within a voltage range not used in normal operation to control a switch operative to disconnect a subscriber termination unit from the line, and to provide a known linear terminating impedance for the line for the duration of the application of the DC voltage.

Abstract: A wire stripper and/or a wire looper are integrally formed in a mounting strap or body of an electrical device, such as a duplex receptacle or wall switch, in order to simplify a wiring installation without requiring an installer to use separate tools.

Abstract: A distribution transformer has a wound magnetic core (50) of overall circular shape and rectangular cross-section with between two and four overall rectangular shape electric coils (20,30) extending through the core window. The coils (20,30) are pre-formed and assembled so that their parts (20A,30A) which meet form a circular section solid cylinder. A mandrel (40) is then located around this cylinder (20A,30A) and continuous non-amorphous steel strip is wound thereon to form an unannealed, uncut wound magnetic core of axial length in the range 250 mm to 1 m. In a modification, amorphous steel strip is first wound on to another mandrel, annealed, and then transferred from the other mandrel on to the mandrel around the coils.

Abstract: In a speed control arrangement for an induction motor or an a.c. permanent magnet motor in which any one of a number of power frequencies may be selected for application to the motor, there is provided circuitry to control the rate of change of frequency from one selected power frequency to another to control the acceleration or deceleration of the motor.

Abstract: A family of wideband amplifier circuits using series and shunt feedback over two stages to achieve constant impedance, including single-ended, single-ended input/differential output and differential input/differential output forms.

Abstract: Device for the precise coupling of two cylindrical parts, especially to form compound tools, with the aid of two cylindrical bodies, one of which has a seat for accepting a pin projecting from the other cylindrical body, it being provided that the front end of the body with the coupling seat be given an inclined wall engageable with an inclined wall branching away from the base of the coupling pin of the other cylindrical body, that the transverse hole in the projecting pin accepts a threaded bush which engages with a cylindrical-headed screw, and that the free ends of the threaded bush and of the screw head have inclined circumferential surfaces engageable with inclined circumferential surfaces defining the transverse holes on the side facing the coupling seat.

Abstract: An amplifier comprising an emitter-coupled pair of transistors having inductive load impedances, with capacitive feedback elements tuned with the inductive loads and the capacitive input of the following stage to be resonant at the range of frequencies to be amplified. The reactive loads and feedback elements introduce less noise than with resistive components.

Abstract: Partially overlapping display elements have light string sets mounted thereon and sequentially illuminated to simulate animation of a decorative part of an outdoor light display.

Abstract: A one-piece, front-opening brassiere has independently adjustable front panels accessible solely from the front of the brassiere, to provide a custom fit especially useful during athletic activities.

Abstract: An optical analysis or processing system for use, for example, in the analysis of microscopic spots of material by their effect on a very fine polarized beam of light (e.g., FPIA). For multiple "spot" analysis the spot samples are disposed on a substrate in predetermined relation with an optical pattern, bars, chevrons, etc. The substrate is mounted in the path of the fixed and focused beam with three degrees of freedom of movement. A video camera records the optical pattern very accurately and controls the substrate mounting to position a selected sample spot at the beam focus. Multiple and rapid sample analysis can thus be performed.