Abstract: An ultrasonic transmitter is disposed on one wall inside the air induction tube of an internal combustion engine and an ultrasonic receiver is disposed on the opposite wall, downstream of the transmitter. A second transmitter-receiver pair is similarly located, but with the positions of transmitter and receiver reversed. Thus, the signals from one transmitter travel generally with the air flow, whereas the signals from the second transmitter travel generally against the air flow. Since the travel time of the signals depends on the velocity of the flowing air, the frequencies of signals from the two receivers are different and this difference is used to determine the air velocity and, hence, the air flow rate.

Abstract: To provide a suitable number of display fields (e.g. ARRIVAL; TIME; etc.), each of which characterizes and identifies the significance or import or meaning of a displayed numerical value on a display device (16), the display fields are associated in groups or sets (11-15; 42-45) having a particular geometric position (columns; segmental), and a plurality of keys (21-25) are provided with each key being associated with a group or set of the display fields, and connected to a counter (61) to select a particular one of the display fields within the group or set by the number of key operations, the numerical value associated with the display field then being displayed on the numerical display (16).

Abstract: A meander-shaped layer of nickel is deposited by evaporation on a ceramic wafer over an intermediate layer of tantalum serving to improve adhesion, and covered by a protective coating of silicon or epoxy resin is used as a temperature sensor in the intake pipe of a supercharged internal combustion engine. The low mass of the sensor element thus provided enables the resistance of the nickel path to follow rapidly, by its variation, the variations of temperature of the intake air. The sensor has a casing made up of two parts, the lower one of which has two connection prongs molded into it, the ends of which are flattened into tabs that are soldered to contact areas of the ceramic wafer. The upper casing portion has a cavity for the ceramic wafer, the lower part of which is filled with a potting compound to protect the solder joints. The width of the nickel paths that provide the temperature sensitive resistance is about 50 .mu.m and the thickness is from 0.2 to 1 .mu.

Abstract: The variable inductor and the comparison inductor of a semi-differential variable inductance both have a pair of coils magnetically coupled together. The output current of an amplitude-controlled oscillator flows through the series combination of one coil of each pair and the other coil of the comparison inductor is used to supply a signal which is rectified in order to regulate the amplitude of the oscillator. The remaining coil, the other coil of the variable inductor, is rectified to provide an output signal representative of the ratio of the variable inductance to the comparison inductance and also representative of the displacement of the short-circuiting ring of the variable inductance, which is mechanically linked to the control rod of a fuel injector of a diesel engine as required for a system controlling the fuel injector. The oscillator and the rectifiers can conveniently use operational amplifiers of the same type designation.

Abstract: The variable inductor and the comparison inductor of a semi-differential variable inductance both have a pair of coils magnetically coupled together. The output current of an amplitude-controlled oscillator flows through the series combination of one coil of each pair and the other coil of the comparison inductor is used to supply a signal which is rectified in order to regulate the amplitude of the oscillator. The remaining coil, the other coil of the variable inductor, is connected in reverse polarity and in series with the coil last previously mentioned to provide, through a rectifier, an ouptut signal representative of the difference between the variable and comparison inductances normalized to (divided by) the comparison inductance. The output variation corresponds to the displacement of the short-circuiting ring of the variable inductance, which is mechanically linked to the control rod of a fuel injector of a diesel engine as required for a system controlling the fuel injector.

Abstract: In order to provide immunity against vibrations, a pressure sensor for detecting the prevailing manifold suction pressure in an internal combustion engine, for example, has a movable chamber which responds to the varying pressure and thereby changes the distance between a diffuse reflector and an optical detector assembly. The detector assembly includes a light source, a first light-sensitive detector and a second light-sensitive detector. The second detector is connected to a regulator which so controls the electrical power to the light source that the induced photo current in the second detector remains substantially constant independently of the distance between the reflector and the detectors. A number of embodiments is presented.

Abstract: A pressure pickup for measuring the pressure in the intake manifold of an internal combustion engine. The pressure pickup comprises a part, movable in response to the manifold pressure, to which is coupled means for short-circuiting the magnetic flux lines of an electromagnet so that the change in flux lines is detected by the electromagnetic coil and measured by an induction evaluation circuit and thus indirectly measuring the manifold pressure.

Abstract: A leveling control mechanism for motor vehicles includes an electric pump and a solenoid valve for raising and lowering the vehicle body and a leveling switch with an electronic damping device. The periodic measurement of the distance from the vehicle axle to the vehicle body is carried out by a mechanical-electrical converter, which converts the rotation of a shaft into an electrical signal. During acceleration and deceleration of the vehicle, as well as during the occurrence of centrifugal forces, suitably situated inertial switches inhibit the response of the leveling control mechanism.

Abstract: A Wiegand wire forms part of a stator coil facing a rotor on which permanent magnets are located. The stator coil has two coil portions or coil sections which are wound or connected to provide opposing inductive outputs upon passage of the magnets in front of the coils to cancel each other, the Wiegand wire change of magnetization providing the additional read-out output, the amplitude of which will be independent of speed, but the recurrence rate will depend upon speed of the magnets passing the stator of transducer.

Abstract: A core with at least three elongated legs, at least one leg being centrally located among all the elongated legs, is joined at at least one end by a yoke portion connecting all the legs. The central leg or legs is wound with a magnet winding close to the yoke portion of the core, with which the core is excited with an alternating field. A short-circuiting ring structure, which may be in the form of an apertured plate, encircles at least the central leg or legs of the core and is movable in the direction of elongation of the core in accordance with the movement of a body the displacement of which is to be measured. The legs of the core may be bent in order to measure rotational or angular displacement. Movement of the short-circuiting ring along the length of the core varies the inductance of the coil in a predetermined manner, which may be a linear relation to displacement. A yoke and a winding may be provided at the other end in order to increase the sensitivity by a differential method of measurement.

Abstract: A group of information carrying flaps are pivoted to the circumference of a drum so that, upon rotation of the drum, the flaps drop down, one by one; the flaps carry information conveying indicia, for example trouble indication during operation of a motor vehicle. The drum is rotated by a motor. To display a specific information item, that is, to permit a specific flap to drop, the flaps are formed with conductive portions which are coded at an edge, the edges being engaged by the holding springs. If the code, which preferably is a binary code, matches that of a binary number entered into one terminal of a comparator, to which the holding springs are connected, the motor is stopped, thus displaying the specific information carried on the flap having the code which matches that of the code entered into the comparator.

Abstract: An inductive transducer is provided with a core with legs extending in opposite directions from a yoke on which a coil is wound. On the leg portions extending on one side of the coil a short-circuiting ring displaceable in accordance with the displacement of a body the movement of which is to be measured is provided and on the leg portions extending on the other side of the coil a compensating short-circuiting ring is provided having a mass corresponding to the total mass of the first short-circuiting ring and the movable portion of the body to which it is connected and the connection therebetween. The effect of acceleration forces produces an equal shift of both short-circuiting rings in the same direction, leaving the total flux linking the coil substantially unchanged. The device can be adapted to measure either linear or angular movement.

Abstract: A variable inductor having a U-shaped magnetic core with a short-circuiting plate providing a short-circuiting ring for both legs of the core movable along the core legs in response to a displacement to be measured is connected in an electronic circuit to generate oscillation of a frequency that is either directly or inversely proportional to the displacement. For the inversely proportional case, the variable inductance component can be combined with an integrator function and connected to an operational amplifier, for generation of the output frequency with a small number of electrical components. The thickness and spacing of the core legs are varied along their length to produce a highly linear inductive transducer characteristic. The core legs are bent in a circle when it is desired to measure an angular displacement.

Abstract: A variable inductor having a U-shaped magnetic core with a short-circuiting plate providing a short-circuiting ring for both legs of the core movable along the core legs in response to a displacement to be measured is connected in an electronic circuit to generate oscillation of a frequency that is either directly or inversely proportional to the displacement. For the inversely proportional case, the variable inductance component can be combined with an integrator function and connected to an operational amplifier, for generation of the output frequency with a small number of electrical components. Additional circuit means may be used to improve linearity at higher output frequencies, or to provide arbitrary non-linear displacement-frequency characteristics.