Daimler-benz Ag

Mercedes-benz Aktiengesellschaft

Manfred Maass

Ingo Dudeck

Martin Fritz

Horst Grossner

Harald Ruoff

Ulrich Hipp

Joachim Bunke

The invention provides a motor vehicle anti-theft system in which an authorization code, representing the access authorization, is transmitted via the vehicle starting line arranged downstream from the ignition switch, to a start release unit. A control unit for the engine start, previously in an engine-start-blocking condition, is thereby placed into a release condition, in which it transmits a start request (arriving from the starting line) to the starter motor. By using the starting line for transmitting the authorization code, it is achieved that the latter is coupled through a connection which is necessary for the start, and therefore cannot fail separately.

Motor vehicle anti-theft device which blocks starting of the engine

An arrangement for limiting the terminal voltage in an alternator has a fixed stator winding acting on rectifiers and an excitation winding which rotates with the alternator rotor. The arrangement also has a controller and a first slip ring contact which load the excitation winding with excitation current as a function of the magnitude of a delivered voltage, and at least one free-wheeling valve which is conductive during a controller-side interruption of the excitation current and is connected in parallel with the excitation winding. The arrangement includes an auxiliary winding on the rotor. The auxiliary winding continues the excitation winding in the same direction of winding, with the auxiliary winding and the excitation winding being connected at a first connection point. A second slip ring contact operatively connects the first connection point to a machine terminal supplying excitation current. A zener diode is connected in series with auxiliary winding, and a third slip ring contact operatively connects the auxiliary winding to a ground terminal of the alternator or of the controller.

Device for limiting the terminal voltage in an alternator

A safety arrangement for an adjusting installation of a seat adapted to be actuated manually or programmed, especially of a vehicle seat, with adjusting motors and with an electronic circuit which gives priority to the manual seat adjustment over a programmed seat adjustment, which, in case of a relay or adjusting motor defect, opens up the corresponding circuit, which in case of a simultaneous actuation of several position buttons, interrupts a programmed seat adjustment and which after interruption of the energy supply permits a programmed seat adjustment only after renewed storage of a seat position.

Safety arrangement for an adjustment installation of a seat adjustable

A device for detecting undesirable combustion processes in internal combustion engines having spark-ignition systems, an acceleration sensor and a band-pass filter tuned to a frequency of a knocking vibration, with an output value of the filter being compared with a reference value, whereby results of the comparison are compared with undesirable combustion processes to be detected. Body noise signals received by the acceleration sensor pass through a band-pass filter. A series circuit composed of a band-blocking filter tuned to the frequency of the knocking vibration, including an r.m.s. rectifier and an amplifier, is provided through which the body noise signal received by the acceleration sensor is converted into a reference signal. A comparator is provided when the reference signal and the knocking signal are compared with one another, whereby an output signal appears when the knocking signal exceeds the reference signal. The band-blocking filter is constructed so that in addition to suppressing the knocking frequency, the filter also suppresses all frequencies below a lower frequency less than the knocking frequency and above an upper frequency higher than the knocking frequency. An output evaluation device is provided for evaluating the reference signal with a factor which is a function of the engine rotational speed, and a timer which acts as a monostable flip flop is disposed after the comparator.

Undesirable combustion characteristic detection apparatus

An apparatus for detecting undesirable combustion characteristics in spark-ignited internal combustion engines. A sensor and band-pass filter tuned to the frequency of the knock vibration are provided with an output of the band-pass filter being compared with a reference value. The result of the comparison is correlated with undesirable combustion characteristics to be recognized. A rectifier is provided for solid borne sound signals received by the sensor with the signals passing through the band-pass filter. The signal is rectified in the rectifier to a knock signal and a series circuit composed of a band-stop filter tuned to the frequency of the knock vibration, an r.m.s. rectifier, and an amplifier is provided by means of which the sound signal received by the sensor is converted into a reference signal. A comparator is provided when the reference signal and the knock signals are compared and an output signal is generated if the knock signal exceeds the reference signal. A time comparison member receives the output signal from the comparator, with the time comparison member transmitting a signal of a predetermined time duration if the time duration of the signal of the comparator is longer than the specific time duration set in the time comparison member.

Undesirable combustion characteristic detector for spark-ignited

An apparatus for detecting undesirable combustion characteristics in spark-ignited internal combustion engines. A sensor and a band-pass filter tuned to the frequency of the knock vibration are provided with an output of the band-pass filter being compared with a reference value. The result of the comparison is correlated with undesirable combustion characteristics to be recognized. A rectifier is provided for solid-borne sound signals received by the sensor with the signals passing through the band-pass filter. The signal is rectified in the rectifier to a knock signal and a series circuit made up of a band-stop filter tuned to the frequency of the knock vibration, an rms rectifier, and an amplifier is provided by means of which the sound signal received by the sensor is converted into a reference signal. A comparator is provided when the reference signal and the knock signal are compared with each other and an output signal appears if the knock signal exceeds the reference signal.

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Esslingen, Germany

Manfred Maass