Abstract: A transistor bridge rectifier circuit, which is capable of being monolithically integrated, is designed to connect the electronic circuits in a user's telephone set to a two-wire telephone line. The circuit includes a transistor bridge with a "Graetz bridge" circuit arrangement, a current generator, a pair of current mirror circuits connected thereto, which alternately conduct according to the polarity of the line, and a pair of controlled current gain transistors, each controlled by the output of one of the two current mirror circuits. The transistors belonging to the opposite sides of the bridge, the bases of which are respectively connected to the emitter and collector of the same controlled current gain transistor, are biased with the same base current which flows through the controlled current gain transistor.
Abstract: A method and apparatus of variable structure for controlling asynchronous motors. More particularly, methods and apparatus for control of flux, torque, angular acceleration, angular velocity, and/or angular position of the rotor of an asynchronous motor, supplied through a converter having switched elements.
Abstract: In an electrical connection system between a payment card (10) including an integrated memory circuit (11), and an information transfer apparatus (15) for reading and writing data in the memory circuit, terminals (14) of the card (10) are covered with a protective layer of a plastic material (13) which is perforable and recoverable (self-healing), and the transfer apparatus is provided, for each terminal, with a projection (16) of hard metal ending at a point (17) to be urged with a defined force on to the corresponding terminal in the card through the protective layer.
Abstract: A cabinet assembly or enclosure which provides an electronically and thermally benign environment for printed circuit boards and the electronic components carried thereby. A wire program device operable from the front of the cabinet permits a changeable interface between the circuits within the cabinet and an external wiring harness. Thermal management for plural solid state power controllers or other heat generating components is achieved through the wire program, and from the use of metal printed circuit boards clamped to a cold plate within the cabinet. A coolant from a remote source may be circulated through the cabinet in contact with the cold plate. The electrical, thermal and mechanical connections are of the zero insertion force type. A novel circuit board for solid state power controllers is also disclosed as is the thermal management of such controllers.
Abstract: In a laminated structure, such as a structural component of an aerospace vehicle or the like, which is fabricated of layers of filament composite material, means is provided for protection against lightning strike damage and electromagnetic interference. In particular, the outer surface layer of the filament composite material is fabricated of conductive metallic-coated filaments to provide a conductive barrier to disperse the current from lightning or other electromagnetic sources. The filaments may be fabricated of a composite material such as glass which has an aluminum coating. The structure may be woven or filament wound with intermixed resin, and the metallic-coated filaments are cured simultaneously with the entire laminated structure of filament composite material.
Abstract: An energy discriminator is employed in conjunction with an adaptive filter to control updating of the filter transfer function characteristic. Specifically, the discriminator is employed to distinguish whether any significant received far end energy is only partial band or whole band. If the received energy is partial band the adaptive filter is inhibited from updating the transfer function characteristic during intervals that such energy is being received. On the other hand, if the received energy is determined not to be partial band and, hence, is whole band, the filter is enabled to update the transfer function characteristic during intervals that such energy is being received.In a specific example, the discriminator is employed in an adaptive echo canceler to inhibit updating an echo path estimate being generated by an adaptive transversal filter when partial band energy is being received and enabling updating of the echo path estimate when whole band energy is being received.
Abstract: The specification discloses a two-directional switched driver for use either independently or in a method of controlling production processes and apparatus therefor. The driver, whether used independently or in a process controller, utilizes polarity signals and a retriggerable timer to produce separate forward and reverse output signals which may be used to drive reversible motors or two-directional actuators by way of standard switching techniques. Examples of such uses are the use of most any reversible motor, or two-directional actuators to control mechanical, pneumatic or hydraulic circuits, such actuators operated by the driver may be rotational or non-rotational in nature.
Abstract: This invention relates to a new system for generating electrical energy by wind power.The wind generator is suspended in the air like a kite by wind currents and is attached to the earth by a high strength cable to which are attached electric cables and a natural gas pipe.The numerous small wind generators are mounted in a box-like kite enclosure, which are raised to the desired elevation by rotary blade power with the assistance of a gas balloon.The wind generator kite is raised and lowered to the proper elevation for maximum electrical output.A complete system, including control methods, permits the production of electricity at a lower cost than conventional methods and provides means for generating large amounts of power with a high load factor.
Abstract: An elevator control system includes an ROM device having control data common to all elevator cars stored therein, and a setting device having a plurality of switches which are selectively closed and opened to designate the ordinal binary numbers of floors of a building served by an associated elevator car. When the building has many floors, the setting device may similarly designate the ordinal binary number of the lower ten floors and those of the remaining floors are additionally stored in the ROM device.
Abstract: A rack for a wall-mounted telephone has an adjustable mounting structure, so that the rack may be mounted alongside different size telephones. The rack is also nestable within another similar rack to facilitate shipping and display of the racks. The rack may be used as a mini-data center independently of the telephone.
Abstract: An echo control system for an adaptive echo canceller which forms a pseudo-echo or its residual signal by combining respective outputs from a tapped delay line holding an estimated characteristic of an echo path as a tap weight and receiving a received signal or its residual signal as an input signal, subtracts the pseudo-echo or its residual signal from an echo signal or its residual signal, and corrects the tap weight using an amount of correction obtained by the resulting residual echo signal or its residual signal and the received signal or its residual signal.
Abstract: An audiometer which can be battery operated, is reliable and economical in current consumption has a digital control unit (10) which controls a LCD in matric form (11, 26). The digital control unit, in its simplest form, includes a data input stage (12) having two inputs (16, 18) receiving, respectively, input signals representative of amplitude and tone, or a spoken word, and a further input (14) which is test-person controlled, to provide a perception signal, operated by the person to be tested when the level of a certain tone, generated by a tone generator (G, 21) is perceived, or a spoken word is correctly heard. The data input stage is connected to a data bus which provides the respective data to a driver circuit (24) to drive the LCD matrix.
Abstract: A transducer for generating a feedback signal representative of the position of a movable member includes a signal generating mechanism for providing an electrical feedback signal representative of the position of the movable member. The signal generating mechanism includes a first shaft portion having a first longitudinal centerline and a drive mechanism having a shaft member coupled in driving engagement to the first shaft portion. The drive mechanism is adapted to be cable connected to one of a plurality of movable members having maximum travel spans different one from the other. The shaft member has a shaft longitudinal centerline which is concentric with the first centerline, the centerlines defining a first axis. An alignment mechanism is coupled to the drive mechanism and the signal generating mechanism and permits limited movement of the first axis with respect to a reference axis. The alignment mechanism thereby isolates the signal generating mechanism from misalignment reaction forces.
Abstract: In a device for producing artificial reverberation by means of a one-dimensional waveguide, a one-dimensional waveguide is utilized, which is obtained using digital circuits which contain at least two line sections of different length, each line section consisting of two parallel digital delay arrangements, one for each direction of propagation. At least one three-gate adapter of the digital wave filter type is arranged between two line sections lying side by side, each of two gates of the three-gate adapter being connected with one of the two mutually facing ends of these two line sections, and the dependent gate of the three-gate adapter being terminated with a frequency-dependent absorber of the digital type. By using a digital one-dimensional waveguide with discontinuities and absorbers, it is possible to reverberate a signal diffusely and with a programmable frequency response of the reverberation time without the disadvantage of a reduced sound to noise ratio due to limit cycles.
January 29, 1982
Date of Patent:
October 2, 1984
AKG-Akustische u.Kino-gerate gesellschaft m.b.H.
Abstract: The disclosure is directed to a steady state signal noise eliminator generally used with fire-fighting equipment including a pair of capacitance and resistance circuits series connected to the input having output signals representative of noise that is phase shifted with respect to the audible signal and is applied to a pair of operational amplifiers connected to the phase-shifting circuits and having their outputs connected to an emitter follower for summing the signals received. A voltage divider is connected to the inputs of the phase-shifting circuits and is connected to a difference amplifier having inputs connected between the voltage divider and an emitter follower to provide an output signal in which only the audible sounds without interference are connected to the output.
Abstract: A loudspeaker system is provided wherein the coils, capacitors, and loudspeaker drive units and combinations thereof are resistively damped to provide electrical damping of the back EMF of these components and thereby reduce ringing in the loudspeaker crossover networks. The result is a measurable and clearly audible improvement in the accuracy of the sound produced by the loudspeaker system.
Abstract: Method and apparatus for automatically controlling exposure of a photographic film by evaluating non-visible spectral scene light frequencies. Particularly for artificially lit scenes, an evaluation of predominantly infrared frequencies is preferred. In one embodiment, the IR scene lighting is evaluated under control of the shutter aperture system while in another embodiment, the strobe itself is controlled by its own photodetector responsive to IR scene light.
Abstract: The invention relates to a process and device for deburring mechanical pieces by laser radiation. The device makes it possible to generate a laser beam of determined power Pa. The laser beam is focused in a focusing spot of a diameter 2.omega.o on the edges of the mechanical piece to be deburred. The focused laser beam causes a volatilization of the burrs of the edge considered: axis ZZ' of the laser beam is approximately concurrent with the edge to be treated and the material is vitrified over a width .omega.o. To obtain, on the edge, a given angle of sharpening .alpha. of a skew surface constituting the edge of a given radius of curvature R, the emission power ##EQU1## where K represents the heat conductivity coefficient of the material of the pieces and Tv and Ts its vaporization and fusion temperatures respectively.
Abstract: A specially designed ribbon for a ribbon loudspeaker is disclosed which prevents ribbon snaking associated with prior art corregated ribbon. The elimination of snaking enables the use of extremely small gaps between the side edges of the ribbon and the magnetic pole pieces which in turn greatly reduce transient distortion of high fidelity sound. Relatively large amplitude corregations are formed within suspended terminal ribbon portions and substantially smaller amplitude corregations are formed within the suspended centralized ribbon portion.
Abstract: A non-conventional electric power source including a reciprocating hydraulically powered ram coupled to an electric generator. A pair of matched nozzles coupling a hydraulic fluid supply to the ram. Reciprocation of the ram is effected by a flapper disposed between the nozzles which alternatingly cuts off hydraulic fluid flow through the nozzles responsive to the ram approaching its travel limit.