Abstract: An elastomer seal is described which is useful for forming a sealed, flat mounting surface on a curved housing. The elastomer seal has a flat sealing face opposite a curved sealing surface. An angled transition surface is adjacent to the curved sealing surface forming a bevel. The bevel assists the seal in properly deforming so that a sealing area is formed across the curved housing. This seal provides peripheral and central contact so that the distribution of compressed seal material is well spread over the surface of the sealed area. The elastomer seal is able to effectively seal housings with radii of curvature from 1 to 6.4 times the curvature radius of the curved sealing surface.

Abstract: Monitoring a room is accomplished by measurement of air pressure where air passage resistance between a secured room and an outside atmosphere is measured and an alarm actuated, if the air passage resistance drops below a predetermined value. Evaluation of typical air pressure fluctuations in a frequency range between 0.01 Hz and 10 Hz is advantageous. The air pressure resistance may be determined by difference measurements of air pressure fluctuations in the outside atmosphere and the secured room, or as a singular process wherein a connecting tube is provided between the room to be secured and the outside atmosphere, where air movements varying as a function of air pressure fluctuations are measured. Devices for the carrying out of the process are described. The devices and the process provide a simple and cost effective alarm system that operates reliably and is secure against outwitting and sabotage.

Abstract: A circuit layout for an infrared space surveillance detector with a sensor and a field effect transistor following the sensor. An operational amplifier with a negative input is connected to the drain electrode of a field effect transistor. The output signal of the operational amplifier is fed back to its negative input. The stabilization of the operating voltage by the operational amplifier is utilized and the drain electrode of the field effect transistor may be supplied with a stable voltage, so that filtering of the operating voltage by a filter factor of 100 to 120 dB, that would otherwise be required, may be eliminated. It is possible further to apply a constant current and/or regulate the current supplied by utilizing the output signal of the operational amplifier to the source electrode of the field effect transistor.

Abstract: A circuit layout for continuous display of power consumption of an electric device includes a light emitting diode actuated by voltage pulses, the frequency whereof corresponds to the current draw of the electric device. It is possible to determine directly whether the instantaneous power consumption of the electric device, in particular a household device, is low or high in case of varying loads as the frequency of the voltage pulses and thus the flashing frequency are below the flicker limit resolvable by the human eye. The power consumption display can be manufactured in a highly cost effective manner and in a compact configuration, so that it may be placed in an electric outlet housing.

Abstract: A circuit layout operating in the current mode for an infrared room surveillance detector includes a high impedance operational amplifier connected directly to a pyroelement used as an infrared sensor. This results in a high sensitivity detector circuit with a low noise component in the detector output signal and maintaining a high impedance detector circuit. The detector circuit has a constant amplification over a relatively broad frequency range. The reaction resistor of the operational amplifier is chosen to have a high impedance, preferably in a range higher than 10.sup.11 Ohm. It is advantageous to take the reference voltage required for the evaluation of the detector output signal from the operational amplifier, so that aside from the simplified circuit layout, no further structural parts capable of increasing the interference sensitivity of the detector circuit are required.

Abstract: When a light-emitting diode is controlled for transmitting high-frequency signals, such as video signals, or quick-changing analog signals, the electro-optical signal conversion is subjected to distortions due to temperature variations in the barrier layer of the diode which arise due to rapidly varying power losses. The circuit presented herein includes a compensating stage operatively connected to the diode, for alleviating such signal distortions. The system is capable of differentiating between the respective conditions of rising and falling edges of the control in the representative signal of signals to be transmitted.

Abstract: A cardan ball suspension having a concentric strap relative to the ball or sphere to be adjusted. The strap exhibits a transverse slot. A radially protruding cog having a rectangular cross-section projects into the longitudinal slot and slides therein. The ball may be pivoted within a spherical angle zone without rotation of a surface element of the ball in relation to its normal or axis. The strap is preferably made of an elastic material and presses the ball against a holder ring.

Abstract: An alarm system for the surveillance of space, with at least one sensor of electromagnetic, in particular infrared radiation, located on the closed inner frontal surface of a rectangular tube having mirror surfaces on its internal surfaces, the use of focusing means, such as lenses, concave mirrors, objectives, and the like, is avoided by that the sensor is essentially adjacent at least in one direction to the opposing mirror surfaces. This yields an alarm system that is highly compact, has small dimensions, and may be produced cost effectively. The sensor preferably consists of two spaced apart sensor elements operated in a push-pull mode.

Abstract: A motion detector of the space surveillance type wherein an elongate box has parallel walls and an aperture opening toward sensors, and a pair of upwardly divergent reflectors is provided for at least one of the two sensing field planes, the reflectors making an angle of 20.degree. or less with each other.

Abstract: A motion detector with at least one sensor to receive electromagnetic radiation, in particular in the infrared range, from a radiation receiver surrounding a monitored object at least partially, and with an evaluating circuit to trigger a control signal upon a change in the intensity of the radiation. A motion detector of this type may be manufactured cost effectively and is suitable for the reception of electromagnetic radiation from an angular range of up to 360.degree. of closed fields of sensitivity because the closed field or fields of sensitivity are formed by the shape of the sensor or sensors.

Abstract: A motion detector responsive to infrared radiation, e.g. for use in burglar-alarm installations, comprises a pair of juxtaposed sensors monitoring adjacent fields of view of a space to be surveyed, giving rise to output signals of opposite polarity upon detecting a disturbance in their respective fields. These output signals are fed to an evaluator comprising two complementary transistors with interconnected emitters and interconnected bases whose junctions are separated by a resistive branch of an RC network, the emitter junction receiving the output signals while the base junction is capacitively coupled to ground or some other point of fixed potential. The collectors of these transistors, energized via respective resistors from opposite terminals of a d-c supply, are connected to respective timers working into a common AND gate which triggers an alarm when an alternation of output signals from the two sensors renders the timers conductive for overlapping periods.

Abstract: A motion detector responsive for infrared radiation, e.g. to use in burglar-alarm installations, comprises an elongate frustopyramidal box with an entrance opening at one end, a concave mirror at the opposite end and four flat, internally reflecting longitudinal walls, two of them converging toward the entrance end on opposite sides of a plane of symmetry with which they include an angle between about 8.degree. and 15.degree.. A pyroelectric radiation sensor near the entrance end, lying in the vicinity of the focal point of the concave mirror, is disposed for illumination by beams of parallel rays in a limited number of fields of view; these beams approach the entrance end at different azimuthal angles, included with the preferably vertical plane of symmetry, but occupy closely adjoining regions inside the box. A planar deflector at the entrance end, bisected by the plane of symmetry, also establishes a limited number of elevational angles for the beams focused upon the radiation sensor.

Abstract: An assembly for mounting an antenna on the body of an automotive vehicle comprises a substantially cylindrical mounting sleeve with an outwardly facing circumferential groove for gripping the edge of a preformed hole in the vehicle body upon an insertion of the sleeve through the hole in a mounting operation. The sleeve is formed with a substantially spherical inner surface in the region of the groove for engaging a matching spherical surface at one end of an antenna casing, the matching spherical surfaces providing a water-tight seal while enabling the casing to assume any of a plurality of orientations with respect to the vehicle body. The sleeve has a bellows-like wall formed at an end opposite the groove with a bead for engaging a cylindrical surface of the antenna casing in a water-tight form fit regardless of the orientation of the casing with respect to the body. A mounting bracket provides mechanical support and an electrical ground for the antenna casing.

Abstract: A cable underpinning usable, for example in spark-plug assemblies, comprises a pipe stub connected to a spark-plug housing and a deformable sleeve provided with a plurality of longitudinal slits or apertures. The pipe stub has a first inner cylindrical surface connected by means of a frusto-conical surface to a second inner cylindrical surface which is smaller in diameter than the surface of the sleeve when the same is in an unstressed or uncompressed state, the second cylindrical surface being provided with a plurality of sharp-edged recesses. Upon the passing of the cable through the sleeve and the force-fit insertion of the sleeve into the pipe stub, bulges are formed in the sleeve which protrude into the recesses, thereby preventing rotary and axial motion of the sleeve relative to the pipe stub. The flexible outer layer of the cable also bulges into the slits, which bulging locks the cable to the sleeve.

Abstract: A reversible d-c motor, driving a load such as a vehicular radio antenna, has its armature winding connected in a transistorized energizing circuit which is activated by a start circuit and locks operated as long as the motor speed surpasses a certain threshold, i.e. until a major obstacle or a terminal position is encountered. The threshold may be determined by a voltage sensor detecting the counter-e.m.f. induced in the armature winding, by a Hall-effect device in the magnetic field of the stator, or by a speed sensor. The armature winding lies in series with a current limiter which determines the maximum torque applied to the load and may also transmit a no-load signal to a protective circuit when the motor is found idling, the protective circuit including a timer which cuts off the motor after a predetermined idling period. Alternatively, the operating period may be determined by a pulse counter de-energizing the motor after a preferably settable number of rotor revolutions.

Abstract: An astable multivibrator with an R/C coupling network establishing a nominal operating frequency in the KHz range works into a chain of binary divider stages stepping down that frequency to the order of one Hz. The last stage output or outputs of the divider chain are connected to the coupling network through a feedback path including a switching transistor, driven into conduction during alternate half-cycles of the multivibrator, whereby the charging rate of the network capacitance is modified in slow steps with corresponding changes in operating frequency. Several intermediate stage outputs of the divider chain are tapped by way of a coincidence gate to energize a loudspeaker via an audio amplifier with a pulse train having a basic cadence of several hundred Hz, modulated by the feedback, and an on/off ratio well below 1:1.

Abstract: A frequency-modulated ultrashort-wave signal is received, but due to wave-reflection phenomena from physical bodies reflecting towards the receiving antenna is amplitude modulated, this amplitude modulation being dependent upon frequency. An amplitude-indicating signal and a frequency-deviation signal are derived from the received frequency-modulated signal and, instead of merely being applied to the x- and y-deflection inputs of an oscilloscope for partly subjective analysis by a skilled analyst, are applied, preferably via low-pass filters, to first and second differentiators, the two output signals of which are transmitted to a divider which produces a differential-quotient signal indicating the rate of change of the amplitude of the frequency-modulated signal with respect to the frequency deviation of the frequency-modulated signal.