Abstract: The present invention comprehends a circuit arrangement for detecting and interpreting interferences with automatic machines and particularly coin telephones. Free use of the automatic machine by manipulations (statically charged persons, electronic cigarette lighters or gas lighters) is prevented by means of a highly sensitive interference discriminator whose input is connected to the housing of the automatic machine or to an antenna, and whose output controls the malfunction detector in such a way that the latter blocks the use of the automatic machine when the discriminator responds.

Abstract: An oxyhydrogen torch for use in drawing an optical fiber from a preform without axial rotation includes four coaxial tubular elements bounding respective passages. The fiber is coaxially drawn through the innermost passage, and hydrogen, oxygen and an inert gas are respectively individually admitted into the successively outer passages at their upstream ends in the circumferential directions of the respective passages. Oxygen and hydrogen become mixed with one another and combust after leaving the downstream ends of the respective passages to form an annular oxyhydrogen flame in a heating zone of the torch around the portion of the preform from which the fiber is being drawn. The inert gas, such as argon or nitrogen, flows past the flame in the heating zone to shield the flame from environmental disturbances.

Abstract: A method of connecting a mechanical seal ring made of hard metal or ceramic to a supporting ring made of aluminum or stainless steel includes pressing the two rings against each other with such a force that the material of the supporting ring yields.

Abstract: A non-volatile programmable integrated semi-conductor cell comprises a semiconductive substrate of one conductivity type, a reading insulated-gate field effect transistor partially incorporated in said substrate and having an insulated gate at the active surface of the substrate, and a floating gate electrode juxtaposed with and extending beyond the boundaries of the insulated gate, a pair of programming electrodes constituted by planar regions of the other conductivity type in the substrate, including a writing electrode and an erasing electrode each having an insulated gate of a thickness permitting junction crossing by hot carriers in partial overlap with floating gate electrode for capacitative coupling thereto, the region of overlap at said writing electrode being larger than that at said erasing electrode, and a diffusion region of the one conductivity type in said substrate next to and at a small distance from said writing electrode and having a surface area smaller than that of said writing electrode,

Abstract: In the method of making an electrodynamic transducer, the magnet part and the coil-diaphragm part are made in separate steps and are then assembled. The coil-diaphragm part is made in a plurality of successive stations; first a plane diaphragm material is adhered to one side of the carrier ring (10), and then a heat activatable glue is applied to the diaphragm in the region where the coil (15) is to be attached, and finally the diaphragm is formed with a heat emitting tool simultaneously with the coil (15) being pressed against the heat activated glue.The transducer has a diaphragm (13) connected to a coil (15) which is moveable in a slit (6) between the pole shoes (3, 4) of a magnet (5), the pole shoes (3, 4) being fitted coaxially on a guide pin (2).

Abstract: A process of treating surfaces of silica or silicate glass, especially in preparation for subsequent coating in the manufacture of optical waveguides includes introducing a gaseous medium containing at least one component which forms hydrogen fluoride when sufficiently heated to the surface to be treated, while an etching zone which covers only a portion of the surface is thus heated, so that the hydrogen fluoride etches the surface only at the etching zone. The temperature is so selected that silicon tetrafluoride formed during the etching is oxidized and the resultant silicon dioxide is deposited from the gaseous medium onto the surface outside of the etching zone to form a fused fluorine-doped vitreous layer on the previously etched portion of the surface.

Abstract: Connection to a tantalum capacitor electrode (17) is effected using a conductive paint layer (15), incorporating pure silver and pure copper particles, which minimizes silver leeching by a tin-containing solder alloy (18) by which the lead wire (17) is connected to the conductive paint layer (15), and thus minimizes power factor degradation.

Abstract: In a Sagnac effect optical fibre gyroscope, which uses a phase nulling photo detection technique to drive a feedback loop controlling one or more non-reciprocal elements connected in series with the coil, a commutating switch reverses the direction of propagation of oppositely directed beams of light directed through the coil and non-reciprocal elements. The null balance is detected as the absence in the photodetector output of any a.c. component in phase or out of phase with the commutation switching. This removes a source of systematic error occasioned by drift in optical parameters of unbalanced components.

Abstract: A switch machine which is connected by two throw rods to the respective switch points to be operated includes an internal locking arrangement which includes two holding elements pivotally mounted on the respective throw rods and accommodated between a sliding member and a displacement member of the switch machine which are disengageably connected to one another. Each of the holding elements has a free end which is enlarged by two tongues respectively extending toward the sliding member and the casing of the switch machine. Depending on the position of the sliding member, the tongues are received in the associated recesses in the sliding member or in the casing to thereby either lock the throw rods in their positions relative to the casing or to entrain the same for movement with the sliding member.

Abstract: In a contactless keyboard including for each key a transformer with a core displaceable by the key operation and including a compensation transformer common to all key the compensation transformer is so designed that with an unactuated key the signal component of the compensation transformer in the signal applied to the evaluation circuit exceeds the component of the key transformer, whereas with an actuated key the signal component of the key transformer predominates. Therefrom results a phase change of the signal applied to the evaluation circuit with the actuation of a key. The evaluation circuit compares the phase of the key output signal with that of a reference signal. For increasing the immunity from disturbance the evaluation circuit delivers an output signal (key operated or key nonoperated) only when several successive comparison operations give the same result.

Abstract: A hydraulic braking system, particularly for motor vehicles equipped with anti-skid devices, includes a housing having at least one chamber accommodating a pressure control unit controlling the pressure of hydraulic fluid admitted into brake circuits leading to respective brake-operating cylinders. The pressure control unit includes an actuating piston which subdivides the chamber into an actuating compartment, a working compartment, a supply compartment therebetween which is sealed from the actuating compartment and communicates with the working compartment through a gap between the piston and the housing, and another compartment at the end of the piston remote from the working compartment. An auxiliary piston is accommodated in the last-mentioned compartment and subdivides the same into two spaces into one of which the auxiliary pressure is admitted at the same time that it is admitted into the supply compartment.

Abstract: Keep-fresh storage container having a two-part lid consisting of a stiff part with handle webs and rim and of a deformable sealing part fastened thereto.

Abstract: In a Sagnac effect optical fibre gyroscope a commutating switch (SW) is included immediately before the Sagnac coil (C). Operation of the switch synthesises turning the coil upside down. This provides the advantages of producing an a.c. signal in response to a constant rotation rate and in certain arrangements remove a source of systematic error occasioned by drift in optical parameters of unbalanced components.

Abstract: Powder is coated with valve-metal by rotating it in a drum 15 so that it is presented to valve-metal vapor derived by evaporation of a source of valve-metal. In the case of coating with aluminum, the vapor may be produced by directing aluminum wire 10 on to a heater 11, and oxygen or air is admitted to control agglomerate formation. Aluminum and tantalum coating are both described using electron beam evaporators.

Abstract: Crystalline semiconductor material is produced in strip or sheet form by a gas process. The corresponding amorphous semiconductor is vapour deposited on to a substrate material which is subsequently removed from the amorphous semiconductor. The semiconductor is then selectively heated to induce crystallization. Devices may be fabricated on the crystalline material in tandem with the deposition and crystallization processes.

Abstract: Encased miniature relay comprises a magnet system with a core, a coil arranged on the core, an L-shaped yoke connected to one end to the core and an angular tilting armature which is, tiltably supported on the edge of the free end of the yoke. To obtain a holding force for the tilting armature, a permanent magnet is arranged in the free end of the magnetic path between the core and the yoke in the proximity of the arms of the armature.

Abstract: A monolithically very large scale integrated circuit (VLSI) having any arbitrarily given structure and an internal test circuit only requiring one, two or three additional outer terminals wherein the test circuit is integrated therein. In one embodiment the test circuit contains a counter and a combinational circuit interconnected with the counter reading outputs thereof as well as selection switches associated with test points and where the first of the additional terminals is connected to the counting input of the counter.