Abstract: Methods and/or devices for detecting the flow rate of a flowing medium, in particular the flow rate of a flowing air mass, are described, in which the flowing medium is detected with two evaluation methods that operate according to different principles and the two measurement signals obtained are set in relation to each other in order to determine correction methods. Since the two measurement methods react differently to interference effects, the comparison of the two output signals permits conclusions to be drawn as to the type and the order of magnitude of the interference effects and a corrected measurement signal can be obtained, which is independent of the interference effects.

Abstract: Methods and/or devices for detecting the flow rate of a flowing medium, in particular the flow rate of a flowing air mass, are described, in which the flowing medium is detected with two evaluation methods that operate according to different principles and the two measurement signals obtained are set in relation to each other in order to determine correction methods. Since the two measurement methods react differently to interference effects, the comparison of the two output signals permits conclusions to be drawn as to the type and the order of magnitude of the interference effects and a corrected measurement signal can be obtained, which is independent of the interference effects.

Abstract: A device for detecting a pulsating variable, for instance the air flowing in the intake tube of an engine, is disclosed in which the signal processing and the correction of the pulsation error are done in an evaluation device which is a constituent of the sensor. At the output of the signal processor, the sensor, for instance a hot-film air flow rate meter, outputs a corrected output signal, which is directly a measure of the variable to be determined, such as the mass of the air flowing in the intake tube of an internal combustion engine.

Abstract: A gas sensor for determining physical values of gasses has a capacitor with a dielectric which is bringable into contact with a gas so that a change of a physical property of the gas leads to a corresponding change of a dielectricity constant of the dielectric, and a gas layer arranged on the gas sensor in a region of the dielectric.

Abstract: A device for determining the throughput of a flowing medium is described, wherein a heater resistor heats at least one upstream and downstream located, temperature-dependent resistor, wherein the resistors, which are cooled at different rates by the flowing medium, are wired to form a bridge, whose diagonal voltage is a function of the temperature difference of the resistors. In the end the mass of the flowing medium is determined from this processed voltage (UM). The control of the temperature of the resistor is performed with the aid of its own heater control circuit which regulates the current through the heater resistor in such a way that the temperature of the heater resistor is a predeterminable function of the temperature of the flowing medium. A temperature compensation, with the aid of which the measuring voltage (UM) is compensated at high temperatures, is performed with the aid of a high temperature compensation stage (DT) and of a converter circuit (UMS).

Abstract: The invention proposes a device for measuring the mass of a flowing medium, in particular the mass of air aspirated by internal combustion engines. The device has a platelike sensor element which is accommodated in a recess of a sensor carrier, and which with a sensor region that has at least one measuring resistor is exposed to the flowing medium in order to measure its mass. The sensor element is accommodated essentially flush in the recess and is retained in the recess by being glued to a bottom face in the recess. The bottom face of the recess of the sensor carrier has a troughlike indentation, which extends at least partially along the circumference of the sensor element outside the sensor region that has the at least one measuring resistor. The device according to the invention is intended to measure the mass of a flowing medium, in particular for measuring the mass of air aspirated by internal combustion engines.

Abstract: A mass flow sensor includes a measuring element arranged on a membrane that is clamped in a frame. The sensor is formed by introducing a recess into a silicon wafer. Through the application of a recess having perpendicular walls, the thickness of the frame can be reduced, thus allowing the required surface area of the wafer to also be reduced.

Abstract: A mass-flow sensor includes a measuring element on a membrane and a media-temperature measuring element on a separate membrane. By configuring the media-temperature measuring element on a membrane, the mass-flow sensor quickly reacts to changes in the temperature of the flowing medium.

Abstract: The invention is directed to a flow sensor having a heater, two temperature measuring sensors, a heater temperature sensor and a medium temperature sensor. A control circuit is provided which controls the overtemperature of the heater in dependence upon the temperature of the flowing medium. With this arrangement, the influence of the temperature dependency of the following on the sensor characteristic are compensated: viscosity, thermal conductance and thermal capacity of the medium. The relationship between the heater temperature and the temperature of the medium is adjusted in a slightly nonlinear manner by means of special evaluation circuits. In this way, a further improvement of the temperature compensation is obtained.

Abstract: A method and apparatus controls the temperature of a precision resistor and, in turn, measures the flow rate of a flowing fluid mass. The precision resistor is a hot wire or hot film of an air mass meter of an internal combustion engine of a motor vehicle. Through timed current flow, the operating temperature of the precision resistor is maintained at a higher temperature than the temperature of the flowing fluid mass. The timing of the electric current for maintaining the operating temperature of the precision resistor is controlled based on the magnitude of the gating voltage supplied to heat the precision resistor.

Abstract: A method and a circuit arrangement for measuring the air flow in the air intake passage of an internal combustion engine provide an output pulse signal which can be easily processed in digital control devices. The unbalance voltage of a measuring bridge, which is thermally coupled with a flow measuring member, is supplied to a voltage-to-frequency converter; a frequency which is proportional to the unbalance voltage of the bridge circuit is provided at the output of the voltage-to-frequency converter for further processing. At the same time, this frequency is used for triggering a monostable multivibrator which connects the flow measuring member with a voltage source in a timed manner.

Abstract: A device for noise peak suppression during a potentiometer evaluation has a potentiometer located between a reference voltage and mass and having a slider with a slider output, a control device adapted to receive a signal from the slider output of the potentiometer, and an amplifying unit located between the potentiometer and the control device so that a signal picked up from the slider output is amplified in the amplfying unit before being supplied to the control device.

Abstract: An apparatus for measuring the mass flow rate of air has a resistance bridge circuit, whose diagonal voltage is applied to a switching control element, which is in turn supplied with voltage pulses for heating a flow sensor probe. The switching control element regulates the heat output conveyed to the probe, and emits an output signal proportional to the mass flow rate of air over the probe. The voltage pulses (U.sub.T) for heating the probe are supplied to a first closed loop control circuit. The first closed loop control circuit emits a first output signal (U.sub.a1), which is a function of the voltage measured across the diagonals of the resistance bridge circuit. A second closed loop control circuit is adapted to receive the first output signal (U.sub.a1) and an input signal (V.sub.2 U.sub.R). The input signal (v.sub.2 U.sub.R) depends on the voltage pulses (U.sub.T) for heating the sensor's probe, a reference variable (U.sub.R), and the first output signal (U.sub.a1).

Abstract: An inductive position indicator in particular for determining an angular position of a throttle flap of an internal combustion engine comprises an oscillator circuit, reversible oscillating circuit branches, a position detecting element cooperating with the oscillating circuit branches for position-dependent change of their inherent frequencies, and an evaluating circuit which determines the position from the current inherent frequencies, the oscillator circuit having two oscillators which in one reverse position cooperate with an associated first respectively second oscillating circuit branch and in another reverse position oscillating circuit elements of the first and second oscillating circuit branches are exchanged with one another so that each oscillator cooperates with a third respectively a fourth oscillating circuit branch of another inherent frequency.

Abstract: In the case of a circuit arrangement with a flow probe operated in a bridge circuit, a device for determining bridge balance, which controls a triggering circuit which can be supplied by an oscillator and controls a switching device for the power supply of the bridge circuit, the oscillator has an operating frequency which is at least approximately inversely proportional to the square of the operating voltage of the power supply.

Abstract: A circuit arrangement with a flow-measuring probe in the form of a hot wire is proposed, the output signal of which is proportional to the operating voltage. For this purpose, the circuit arrangement comprises an oscillator which drives a bistable flipflop which, in turn, opens or closes a switch connecting a bridge circuit and operating voltage under cycle control. The diagonal voltage of the bridge circuit is supplied to the input terminals of a comparator the output connection of which is connected to the reset input of the bistable flipflop. The Q output of the bistable flipflop controls a transistor which connects an integrator circuit to the operating voltage when the switch connecting bridge circuit and operating voltage source is closed.At the output of the integrator circuit, an output signal proportional to the operating voltage is available for further processing.

Abstract: An apparatus for determining the flow rate of a flowing medium having a substrate as a carrier and a resistor arrangement disposed on the substrate which among other elements includes a layer-like measuring resistor (R.sub.H) as well as a likewise layer-like heating resistor (R.sub.S), the heating output of which is regulated such that the measuring resistor (R.sub.H) has a constant temperature, the heating output of the heating resistor (R.sub.S) being a standard for the flow rate of the flowing medium. The surface area of (R.sub.S) is greater than the surface area of (R.sub.H) and extends farther toward a fastening of the substrate, in order to prevent a flow of heat out of the vicinity of the measuring resistor (R.sub.H). The measuring resistor (R.sub.H) and the heating resistor (R.sub.S) are located on the downstream portion of the substrate, on a lip set off by a slit. With this disposition of the measuring resistor (R.sub.H), soiling of the substrate affects the measurement result only slightly.

Abstract: A method and an apparatus are disclosed for determining the flow rate of a flowing medium such as the amount of air supplied to an internal combustion engine. The apparatus includes at least one temperature-dependent resistor arranged in the flowing medium. For this purpose, an arrangement is provided which applies a quantity dependent on at least the flow rate to the temperature-dependent resistor. The method includes the step of abruptly reducing the flow rate dependent quantity to a value such as approximately zero in the presence of a flow-rate value lying below a predeterminable threshold value. Because the reduction takes place only for a predetermined period of time, normal operation will be resumed automatically when the flow rate rises again. A hot-wire air-flow sensor is arranged in the intake pipe of an internal combustion engine and the output signals thereof are a measure of the amount of air inducted by the internal combustion engine.