Abstract: Protective circuit and a method for operating said protective circuit in particular for overvoltage protection for an electronic control system for a motor vehicle protective circuit, comprising a control unit (1) and a switch unit, with the switch unit monitoring an input voltage of a voltage regulator (2), which is directly or indirectly associated with the supply voltage (VCC) of the control unit (1). If this input voltage (UBAT) exceeds a predetermined threshold voltage (USCHWELLE), the control unit (1) switches in one or more loads. If the control unit has an idle mode and an operating mode, it is switched from idle mode to operating mode and if necessary a further load (RL) is switched in.

Abstract: A device for identifying authorization and triggering/enabling an action. The device comprises a base unit that detects identity information of a key unit, compares it with predetermined identity information and, if there is a match, triggers or enables the action. The base unit and the key unit each include synchronous generators outputting digital information that changes at predetermined time intervals. The key unit combines information of the digital generator with stored identification code to form a coded information item. The base unit codes the predetermined identity information with information from its own generator and compares this coded information with the coded information from the key unit. If the base unit detects the coded information, the action is triggered. The base unit outputs a signal, the key unit switches an antenna between matched and mismatched states, the antenna reflects the received signal, and base unit evaluates the reflected signal.

Abstract: Circuit arrangement for detecting the state of at least one electrical switch having at least one set input (Set1, Set2, Set3) in each case and at least one sensor output (Sensor1, Sensor2, Sensor3) in each case, each of which is allocated to an electrical switch (S1, S2, S3), wherein the sensor output (Sensor1, Sensor2, Sensor3) is connected via a first current path to a first potential if a signal with the value logic “1” is present at the set input (Set1, Set2, Set3) and is connected via a second current path to a second potential if a signal with the value logic “0” is present at the set input (Set1, Set2, Set3), and wherein a wake-up signal is generated at a wake-up signal output (wakeup) if a current which is greater than a predetermined threshold current is detected in the first or second current path.

Abstract: In a transmitting and receiving method, a request signal is transmitted between a first and an additional transmitting and receiving device by means of a bi-directional first communications path. According to the request signal, a second communications path is established for a predetermined time interval and the receiving power in the additional transmitting and receiving device is measured by means of a measuring device.

Abstract: Anti-theft protection system for a motor vehicle, and a method for operating an anti-theft protection system. The anti-theft protection system has a transmitting and receiving unit in the motor vehicle, which transmits radar signals modulated over a broad bandwidth and then waits for echo signals. A code transmitter, which receives a radar signal, for its part sends back an additionally modulated and coded signal. An evaluation unit analyses all the received echo signals firstly for authorization of the code transmitter and secondly in order to determine the distance between the code transmitter and the transmitting and receiving unit.

Abstract: Circuit arrangement for detecting the state of at least one electrical switch having at least one set input (Set1, Set2, Set3) in each case and at least one sensor output (Sensor1, Sensor2, Sensor3) in each case, each of which is allocated to an electrical switch (S1, S2, S3), wherein the sensor output (Sensor1, Sensor2, Sensor3) is connected via a first current path to a first potential if a signal with the value logic “1” is present at the set input (Set1, Set2, Set3) and is connected via a second current path to a second potential if a signal with the value logic “0” is present at the set input (Set1, Set2, Set3), and wherein a wake-up signal is generated at a wake-up signal output (wakeup) if a current which is greater than a predetermined threshold current is detected in the first or second current path.

Abstract: A circuit for the selective activation of a plurality of antennas (L1 to L4) from a common end stage (8) contains a first selector switch (10) at a terminal (6) of the end stage (8), the switch contacts (12, 22) of which are each connected to a switch contact (20, 26) and via an antenna (L1, L2) each to one fixed contact each of a twin selector switch (14, 24). The fixed contacts of the twin selector switch are each connected via a further antenna (L3, L4) to the other terminal (18) of the end stage and these are also connected to the other switch contacts (16, 28) of the twin selector switch.

Abstract: Anti-theft protection system for a motor vehicle, and a method for operating an anti-theft protection system. The anti-theft protection system has a transmitting and receiving unit in the motor vehicle, which transmits radar signals and then waits for echo signals. A code transmitter, which receives a radar signal, modulates this signal and sends it back. An evaluation unit analyses all the received echo signals firstly for authorization of the code transmitter and secondly in order to determine the relative interior/exterior position of the code transmitter with respect to the motor vehicle.

Abstract: The invention encompasses a method for identification of a mobile station which is assigned to a base station. The base station has a first low-power mode in which the base station transmits on a clock cycle. The mobile station receives on the same clock cycle and carries out an initial check to determine whether a base station signal is being received. The mobile station has a second high-power mode in which the mobile station lengthens the time period of reception to synchronize with the clock cycle and interchange identification data with the base station. The invention also encompasses a circuit arrangement in particular for carrying out the method.

Abstract: A communication system for a motor vehicle including a first voltage supply line, a second voltage supply line, a first electronic apparatus, and a second electronic apparatus. The first electronic apparatus is connected to the first and second voltage supply lines and transmits data over the first and second voltage supply lines. The second electronic apparatus is also connected to the first and second voltage supply lines and receives data over the first and second voltage supply lines.

Abstract: A motor vehicle is provided with a usage authorization checking device that detects biometric data of a person with a biometric sensor configuration. If the usage authorization check, performed with biometrically detected data, is positive, the vehicle can be put into operation by performing a predetermined actuation without actuating a separate ignition or starter switch. A separate ignition or starter switch is eliminated. The driving motor can be an electric motor or an internal combustion engine. The predetermined actuation can include movement of an accelerator pedal, a transmission shift lever, a clutch pedal and a brake pedal. The biometric sensor configuration can also include connections to a driving motor start-up device and a shut-off device.

Abstract: Anti-theft protection system for a motor vehicle, and a method for operating an anti-theft protection system. The anti-theft protection system has a transmitting and receiving unit in the motor vehicle, which transmits radar signals modulated over a broad bandwidth and then waits for echo signals. A code transmitter, which receives a radar signal, for its part sends back an additionally modulated and coded signal. An evaluation unit analyses all the received echo signals firstly for authorization of the code transmitter and secondly in order to determine the distance between the code transmitter and the transmitting and receiving unit.

Abstract: A power supply system contains two batteries and a load device which is connected to the batteries such that, upon failure of one of the batteries, the other takes over the supply of power. The batteries and the load device are connected to one another by a single ground line and arranged such that, upon an interruption between the interconnected grounds of the batteries and the ground of the load device, the load device is fed with the difference voltage of the batteries. A reliably operating power supply system is created which is operational by with only one ground line.

Abstract: Anti-theft protection system for a motor vehicle, and a method for operating an anti-theft protection system. The anti-theft protection system has a transmitting and receiving unit in the motor vehicle, which transmits radar signals and then waits for echo signals. A code transmitter, which receives a radar signal, modulates this signal and sends it back. An evaluation unit analyses all the received echo signals firstly for authorization of the code transmitter and secondly in order to determine the relative interior/exterior position of the code transmitter with respect to the motor vehicle.

Abstract: A remote-control access control device, particularly for motor vehicles, includes a stationary transmitter and receiver unit responding to actuation of tripping means for transmitting a question code signal, receiving an answer code signal, and furnishing an unlocking signal to an unlocking unit if the answer code signal matches a command code signal. A portable transponder has a receiver receiving the question code signal and a transmitter transmitting the answer code signal. The question code signal is repeatedly transmitted if no answer code signal has been received in response to an initial transmission, and a signal parameter is modified upon transmission of the answer code signal as a function of a field intensity of the question code signal or of a battery voltage of the transponder. Alternatively, a signal parameter is modified when the answer code signal is transmitted if an information content of the question code signal indicates an emergency operation state.