Robert Boschgmbh

Gunther Kaiser

Immanuel Krauter

Werner Nitschke

Helmut Denz

Werner Jundt

Manfred Mezger

Edmund Jeenicke

Karl Ott

Gunter Honig

Martin Zechnall

Winfried Klotzner

Gerhard Lotterbach

Udo Zucker

Michael Kirschner

Rudiger Jautelat

Walter B Hersel

Helmut Gross

Dieter Mayer

Wolfgang Hoptner

Klaus-Gerd Meyer

Peter Etzold

Siegfried Hertzler

Alfred Bruckelt

Heinz Kraemer

Wolfgang Groschel

Michael Henn

Distributorless ignition system

The resistance to supply voltage, e.g. battery, fluctuation of an input/output circuit for a control system, e.g. vehicular ignition/fuel injection system, is improved by placing a comparator K in each analog input line, and using a voltage divider UD to compensate the reference voltage U.sub.R applied to one of the comparator inputs. Processing speed is increased by using digital comparators 22-26, which test not only for threshold value equal to counter state, but also for threshold value greater than counter state, in the duty-cycle modification circuit. Chip count is reduced and integration is increased by using a single voltage divider to supply all the input comparators and by using a High-Speed Output (HSO) port on the central processing unit (CPU) to perform multiple output tasks.

Vehicle control system with HSO-triggered output

Process for fuel metering

To prevent change of data in a non-volatile programmable, ready-only memory (25) forming, together with a microprocessor (23) a control unit, for example for an automotive vehicle, while permitting programming of the memory from an external programming unit (P, 1), an interface (3, 11, 12) is provided through which a release-enable bus (13) also passes, data being transmitted in accordance with a predetermined characteristic--even or odd parity--, the parity correctness being checked. If the parity is correct, an 'enter' signal is provided on the release-enable bus for storing the data; if not, retransmission is attempted for a predetermined number of time, and if it cannot be correctly effected, a malfunction indication output signal is generated.

Externally reprogrammable vehicular microcomputer with hardware lock-out

To control the ON or conduction time of a transistor (4) serially connected with the primary winding (2) of an ignition coil, the voltage drop across the collector or base respectively, and emitter is sensed and used as a control parameter with respect to a set or reference value determining current flow through the ignition coil under conditions of complete discharge of stored energy from the ignition coil. Conditions of complete discharge occur within a first speed range; in other speed ranges, in which residual stored energy remains within the ignition coil, indicative of current flow therethrough starting from a value other than zero or null, the voltage sensed across the transistor is compared with the reference value, and the current flow time adjusted in dependence on the comparison.

Method of stabilizing current flow through an automotive-type ignition

Method and apparatus for self-monitoring of microcomputer-controlled

A sensor for the variable underpressure in the intake manifold of an engine produces a digital output signal which is sampled at intervals of one half of the period of pressure variation or an odd multiple of such half period, as timed in synchronism with the crankshaft revolution in a phase relation designed to intercept maximum and minimum values of pressure. The two most recent samples are stored in a shift register and their difference is formed by digital subtraction, compensated for changes of sign in successive difference operations to provide an absolute difference value output. The latter is then provided to a threshold stage which provides an output signal if the difference value does not reach a predetermined threshold. The signal of the threshold stage is integrated before it is used to produce an alarm indication or a corrective control function. When such an indication is produced, the value of pressure measured by the sensor is referred to in order to determine whether the malfunction relates to the communication of the vacuum to the sensor or to a defect in the sensor itself.

System for monitoring the sensor responsive to a periodic condition in

To permit simple computation of control parameters, for example by an engine microcomputer, operating parameters of the engine are signalled by sensing instantaneous operating conditions such as speed, induction air pressure, or the like, preferably at a sensing angle of the crankshaft in advance of top dead center (TDC) position of a reference piston, and the average value is then determined by weighting the sensed instantaneous value to relate it to an average value in a weighting circuit (16). Preferably, the sensed signal is additionally modified in a function generator (15) as a function of then pertaining average conditions of at least one of: speed n; loading L.

Apparatus for determining the value of a cyclically varying parameter of

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Stuttgart, Germany

Gunther Kaiser