Abstract: A key device for producing binary codes, wherein an output shaft is rotated by any of separately provided keys in sliding contact with the inner wall of a hole penetrating an outer casing; a plurality of push pin assemblies are provided; a plurality of switch means are arranged each corresponding to each push pin assembly; there are separately provided a plurality of keys for rotating an output shaft, each of which has longer and shorter grooves to push each push pin assembly; each push pin assembly normally locks the output shaft to the outer casing; each push pin assembly is formed of at least first, second and third linearly arranged unit pins; when pushed by either or both of the longer grooves and shorter grooves, each push pin assembly unlocks the output shaft for rotation; when the output shaft is rotated through a prescribed angle, each push pin assembly selectively operates the corresponding switch means according to the lengths of the longer and shorter grooves by which said push pin assembly is pus

Abstract: An audio frequency power line carrier control system utilizing an inverter as the carrier control transmitter with the output phase voltages of the inverter fed to a distribution network through a series inductance, a filter circuit and a current transformer in which a starting control is provided which modulates the audio frequency pulses at the beginning of clock pulses for transmitting data using a control signal which is pulse width modulated, modulation being terminated when the pulse width of the control pulse width falls below a predetermined minimum duration thereby permitting small series inductances to be used.

Abstract: Stencil cutting apparatus for electrically burning information from an original document into a stencil material having non-linear burning characteristics by the application of electrical pulses to a stylus contacting the stencil material positioned on a rotatable cylinder, includes a photomultiplier for scanning the original document and providing an output signal the amplitude of which is proportional to the light reflected by the information thereon, a circuit including a square wave oscillator and wave shaping network which alters the square wave in relation to the burning characteristics of the stencil material to produce a resultant train of pulses and a comparator circuit which adds the photomultiplier signal and train of pulses. The comparator provides output pulses having a width determined by the addition of the last-mentioned signal and pulses which are fed to the stylus for burning the stencil.

Abstract: Apparatus as described for indicating, for alarm and/or safeguard control purposes, when the value of a second parameter lies beyond (i.e. is above or below) a predetermined limit. The apparatus includes two or more sensors each arranged to provide a respective warning signal when the parameter lies beyond a respective specified value, the value for at least one of the sensors being equal to or beyond the predetermined limit; and logic means including a validation circuit connected to the two sensors and arranged to provide a "parameter-beyond-limit" signal, which may be used, for example, to operate an alarm and/or an emergency trip, only when both sensors provide a warning signal. Various forms of apparatus are described in which the parameter sensed is the level of water in various items of steam plant as used in power stations, e.g. boilers, vacuum condensers, bled steam lines and direct contact feed heaters, to provide an indication of high and/or low water level.

Abstract: A magnetic device which can be driven by means of electromagnetic radiation and has a radiation-sensitive element consisting of cobalt-doped yttrium-iron garnet. Exposure to electromagnetic radiation produces a decrease of the magnetic permeability of the element which decrease is permanent until the element is demagnetized and occurs at temperatures from 77.degree. K to room temperature.

Abstract: A method and apparatus for providing vigilance alarm in or about a multiple station installation as may be used basically in an apartment complex or neighborhood but may be extended to include any number of station alerts wherein an undesired disturbance at one station will be made known with characteristic identification at all remaining stations in the system. The apparatus includes at each station a similar type of unit which consists of a radio transmitter and receiver, the transmitter of which can be energized to transmit an alarm signal indicative of that particular station to all receivers of remaining stations; and receivers of remaining stations thereafter energize frequency selective response circuitry in order to indicate and give audible alarm of disturbance at the transmitting station.

Abstract: An intersection emergency warning apparatus, remotely controlled from an emergency vehicle, for warning persons in proximity to an intersection as to the approach of the emergency vehicle, independent of other intersection traffic control devices. A transmitting device is mounted on the emergency vehicle for transmitting activation signals to a receiver which is mounted on a housing adjacent to the intersection. A visual warning device and an audible warning device are also attached to the housing and to the receiver. As the emergency vehicle approaches the intersection the activation signals are transmitted from the vehicle and received by the receiver located at the intersection. The activation signals activate the audible and visual warning devices, thereby alerting persons in the proximity of the intersection as to the approach of the emergency vehicle. This warning is independent of other intersection traffic control devices.

Abstract: A transparent keyboard switch which is suitable for use in switch arrays is disclosed. Switch nomenclature may be positioned behind the switch and viewed from in front of the switch. The transparent switch comprises a relatively rigid electrically insulating transparent substrate having a "lower" electrode disposed on the upper surface thereof and a relatively flexible transparent film having an "upper" electrode disposed on the underside thereof and a layer of electrically insulating fluid spacing the upper electrode from the lower electrode. The switch is rendered conductive by pressing on the flexible film to locally displace the electrically insulating fluid from between upper and lower switch electrodes and bring them into contact, thereby making the switch a closed circuit.

Abstract: An emergency traffic control system is disclosed for use with emergency vehicles to control traffic signal lights. A coded transmitter employing frequency shift keying is provided in the emergency vehicle and upon actuation, transmits a coded signal to a traffic signal light which is provided with a receiver. Upon reception of a verified signal, the receiver causes the signal light to indicate a steady red in all directions. The emergency system further includes a test circuit for positively determining whether the traffic signal is under control of the emergency vehicle to prevent an accident if two emergency vehicles are simultaneously trying to control the same traffic signal light.

Abstract: An optical system for guiding the pilot of a ground-maneuvering aircraft towards a parking bay has, an illuminated target positioned behind a fixed stop aperture along a line of sight of the pilot which is inclined to the direction of approach of the aircraft to the bay. As the aircraft advances different areas of the target come successively into sight by parallax, and these may be differently colored to indicate the correct stopping position and also whether the aircraft is to the left or right of the correct approach line.

Abstract: A remote meter-reading system interrogates meter stations over power lines and receives encoded meter readings over the power lines in synchronism with the power line frequency by superimposing a digitally modulated signal over the 60-Hz power frequency. The central control station transmits at a data rate of 60-baud and receives at a data rate that is 60-baud or a submultiple thereof, to reduce the demands on the remote meter station transceiver as compared to those on the central control unit transceiver. The bit clock at the central control unit and the meter stations is derived from the 60-Hz power line phase available at each station. Each meter station achieves message synchronization by continuously monitoring the data bit stream for a preset synchronization code and thereafter treats the following 21 data bits as address and function codes.

Abstract: A multiple data channel wireless data coupling system which transmits measured data from a plurality of rotating data sources to a stationary receiver. It includes several rotating transmitters, each producing a unique carrier frequency, which are capacitively coupled to a stationary receiver. The transmitters are supplied power from a relatively low frequency power source through an inductive coupling. The low frequency power source is also utilized to synchronize all of the transmitters as well as the receiver.

Abstract: An apparatus is described for reading a radiation-reflecting record carrier on which information is stored in an optically readable track-shaped phase structure. The apparatus inter alia includes a radiation source, an objective system and a radiation-sensitive detection system. By a suitable arrangement and a suitable choice of the power of a cylindrical lens, which lens in conjunction with a four-quadrant detector supplies a focussing signal, it is possible to detect centering-errors with the aid of only two additional detectors in the plane of the four-quadrant detector.

Abstract: A rotating electric field is generated in the vicinity of a rotating member, the electric field having an axis of rotation coinciding with the axis of rotation of the member. An electric-field sensing or reading device is positioned at the rotational axis of the electric field and associated therewith for detecting variations therein as the electric field passes the rotating member, and creates an electrical output whose relative phase is dependent upon the angular orientation of the rotating member.

Abstract: A code practice blinker light is to be used in conjunction with a tape or record player sending code. The output signal of the tape or record player drives the input base circuit of a transistor, the switching action thereof causing the closing of a series circuit including a lamp which flashes on and off in response to the input audio signal.

Abstract: A visual communication system using color coded lights through which the RAPCON facility at an airport keeps the control tower informed as to the status of aircraft under its control. Three approach zones based on distance from the runway are defined by the colors white, amber, and green, green being closest to the runway. Keyboards are provided at the RAPCON and the control tower, each having three illuminated primary white, amber, and green keys and three illuminated secondary white, amber, and green keys, the primary keys representing the lead aircraft in their zones and the secondary keys representing a second aircraft, if any, in the zone. Upon entry of an aircraft into a zone, the RAPCON operator actuates a primary or secondary key for that zone, as appropriate, causing flashing illumination of the key. The control tower acknowledges by momentarily depressing the flashing key, which steadies its illumination.

Abstract: A memory content is cleared by a clear signal which is formed from a combination of input information known by only a specified person. Said clear signal is developed by a combination of keyswitch inputs, or a combination of a keyswitch input and dial switch input, which dial switch is spatially separated from a clear unit.

Abstract: A sensor for remotely monitoring a physical stimulus is rendered completely self-contained by utilizing the equivalent electrical signal transduced from the stimulus to power an A. C. signal source as well as to modulate the A. C. signal generated therefrom before transmitting the modulated A. C. signal to the remote monitoring location.

Abstract: A method with wide process margins for producing a plated-wire memory elet with both good unipolar disturb resistance and burst read resistance. The method comprises adding the additional process step of dipping the wire after the first permalloy layer or a portion thereof has been plated into a bath of a chromium chloride solution so that a thin, discontinuous chromium chloride film overlays this inner permalloy layer. The rest of the first permalloy layer (mated-film process) or the second permalloy layer (mated-film process) may then be plated over this chromium chloride film.

Abstract: In a laser beam scanning system for recording information on a recording material employing a rotating mirror, a photodetector is provided to receive a laser beam in the start position of rasters. The photodetector supplies a synchronizing signal for making a synchronization between the laser beam scanning and a video signal supplied to a light modulator to modulate the laser beam. The frequency of base clock pulses is several times as large as that of the video clock pulses, whereby the start positions of the effective rasters on the recording material are aligned with each other.