Abstract: The invention is directed to a circuit arrangement for evaluating the signals of an inductive sensor such as the kind utilized on internal combustion engines. The coil of the inductive sensor is connected via a coupling capacitor to a differential amplifier connected in the form of a comparator. The coil of the sensor is also connected via the coupling capacitor to a resistance for equalizing charge as well as to a peak-value detector. The peak-value detector is connected to the input of the comparator either directly or via an amplifier circuit and effects a threshold adjustment for the comparator which occurs in dependence upon the signal supplied by the inductive sensor and in dependence upon the rotational speed. Manufacturing variations of the inductive sensor as well as temperature changes have no influence on the output signal.

Abstract: A method and an apparatus are proposed for adapting the exhaust gas recirculation rate in internal combustion engines, in particular Diesel engines. In order to prevent the smoke which is produced at first in new engines, or when injection nozzles or the like are replaced, an adjustment is made in the exhaust gas recirculation rate, acting as a supplement to the change in this rate which is conventionally made, the supplementary adjustment being preferably performed in stages and with reference to the function of the duration of operation from the time the varying operating conditions begin. The number of injection events is counted and successive memory locations are triggered at time intervals, effecting an adaptation of the exhaust gas recirculation rate up to the final status, each stage in adaptation being stored permanently in memory as it is attained.

Abstract: The Schmitt trigger threshold switch which produces rectangular waves in response to the output of a rotary ignition timing generator has a variable bias applied to its switch-in threshold which is proportional to the amplitude of the generator output, while the switch-out threshold remains fixed at or near zero voltage. The bias, which may be developed by a peak detector, prevents inherent ignition timing shift as the generator turns faster. The Schmitt trigger utilizes an inverting comparator so that a "lowest-wins" circuit can be used for applying stabilizing negative feedback or bias to the comparator. The bias provides immunity to disturbing voltages which increase with signal amplitude.

Abstract: A method and apparatus for determining the injected fuel quantity in internal combustion engines having self-ignition are proposed. A performance graph is prepared which includes the injected fuel quantity per stroke in accordance with the injection duration, with the rpm as a parameter. In order to avoid a fictive 0 point, the injection duration is shortened by a predetermined period of time and multiplicatively linked with an rpm signal, while linear rpm correction curves having a dependency of the rpm voltage on the injection duration can be assumed. At the output of an integrator by means of a sample and hold circuit, an injection quantity signal is produced whenever the rpm signal (Un) is supplied to the integrator for the integration process and the duration of the integration is determined on the basis of the injection duration signal (SD).