Robert Boschgmbh

Seg Automotive Germany Gmbh

Carsten Raudzis

Thomas Friedrich

Frank Schatz

Daniel Christoph Meisel

Heinz Eisenschmid

Ning Qu

Axel Franke

Michael Stumber

Hans Braun

Klaus Heyers

Ulrich Wagner

Mathias Reimann

Bernard Opitz

A method for measuring an air mass flow flowing in a main flow direction, and a hot-film air mass meter by which the method is able to be realized. The method and the hot-film air mass meter are especially suitable for use in the induction tract of an internal combustion engine. The hot-film air mass meter includes a sensor chip having a chip surface across which an air mass flow is able to flow. The chip surface in turn has a measuring surface, the measuring surface including a central hot-film air mass meter circuit having at least one central heating element and at least two temperature sensors. The method is implemented so that the at least one central heating element is periodically heated using a frequency &#x3c9;. With the aid of at least two temperature sensors, at least two measuring signals are detected. The measuring signals and/or at least one differential signal of the at least two measuring signals are modulated using the frequency &#x3c9;.

Hot-film air mass meter having frequency-modulated signal detection

An electric motor, in particular a starter device for internal combustion engines in which a current-limiting electric resistor () with a negative temperature coefficient is connected at the beginning of the main current path () of an electromagnetically excitable rotor () of the electric motor (). The electric resistor () contains at least one monocrystalline semiconductor.

Electric motor

An integrated microstructure sensor element is proposed for detecting thermodynamic measured variables of a fluid. To that end, a supporting body, particularly a board or a wafer having at least one microstructured heating element in contact with the fluid during operation, is provided, on which or in whose vicinity are arranged first arrangement for at least intermittently acting on the heating element with an electric alternating current of defined frequency or a defined frequency band, as well a second arrangement for detecting the amplitude of the third harmonic wave of the electric voltage applied to the heating element. The proposed microstructure sensor element in the form of a compact, integrated component is suitable in particular for determining or monitoring the thermal conductivity and/or the thermal capacity of a fluid, particularly an oil in a motor vehicle.

Integrated microstructure sensor element for detecting thermodynamic variables of a fluid

A capped microsensor is described. It is suggested that a current conductor, positioned in the cavity and having at least two voltage taps, be provided, this configuration being used for seal testing, e.g., during quality control, by detecting at least one thermodynamic variable of a gaseous medium present inside the cavity via this configuration.

Capped microsensor

Growing community of inventors

Leinfelden-Echterdingen, Germany

Carsten Raudzis