Robert Boschgmbh

Karl Staiger

Klaus Streit

Hartmut Seiler

Gerhard Conzelmann

Karl Nagel

Ulrich Drews

Peter Rapps

An air flow rate meter in an internal combustion engine which functions on the principle of a constant-temperature anemometer is proposed. The device includes a resistance measurement bridge with a regulatable total bridge current, and the relative orientation between the bridge diagonal voltage and the input voltage of a subsequent amplifier is variable. By means of this variation, an adjustment can be made of the set-point and actual curves of the air flow rate meter. In accordance with a first exemplary embodiment, a supplementary current is supplied to one of the connecting lines of the bridge diagonal and the amplifier; in accordance with a second exemplary embodiment, a voltage divider is located between the bridge diagonal points, and one of the voltage divider resistors is connected parallel to an amplifier having a specific offset voltage.

Air flow rate meter for an internal combustion engine

A controlled main switch, typically a semiconductor switch, is connected in parallel to the load. In accordance with the invention, an auxiliary switch, typically also a semiconductor switch such as a switching transistor is directly connected across the terminals of the load, and with an impedance, for example a resistance, diode, or Zener diode to the main switch, and controlled to switch in synchronism with the main switch, so that the residual voltage across the load due to inherent voltage drop across the terminals of the switch becomes a minimum. Integrated technology may be used, combining preamplifiers and distribution networks in one monolithic chip.

Switching system to short-circuit a load with minimum residual voltage

A voltage regulator of the type suitable for production as a monolithic integrated circuit for use with a separate reference voltage source is composed of a differential amplifier having a so-called current mirror circuit coupling its outputs, followed by a current amplifying circuit from the output of which a feedback voltage obtained from a resistive divider is brought back to one input of the differential amplifier, the other input thereof being for connection to the reference voltage source. Stabilization of the regulator is obtained by connecting a small capacitance, of a magnitude suitable for provision as an element of a monolithic integrated circuit, between one of the poles of the supply voltage and the point of connection between the differential amplifier and the current amplifier circuit. The differential amplifier has a current source between common emitter connection and ground. The stability condition is worked out showing that the sum current of the differential amplifier must be unusually small. When a multi-transistor current amplifier is used, a second small capacitance is connected in to improve performance. The capacitances may be base-collector diodes, base-emitter diodes, MOS elements, or the like.

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Wannweil, Germany

Karl Staiger