Abstract: A method and a device for determining the state of a vehicle battery in which the battery voltage is measured and information regarding the state of the vehicle battery is derived from the measured battery voltage by means of an integration procedure. A variable weighting factor is taken into account in the integration procedure.

Abstract: A method and a device for determining the state of a vehicle battery in which the battery voltage is measured and information regarding the state of the vehicle battery is derived from the measured battery voltage by means of an integration procedure. A variable weighting factor is taken into account in the integration procedure.

Abstract: A control device for an on-board electrical system with at least two batteries which can be charged by a generator and serve to supply various consumers is described. This control device is located between the two batteries and includes a supply network element, a bus-capable microcomputer, a direct voltage converter, and a short circuit proof end stage. The control device is supplied with information via various terminals, and via other terminals the control device can output control signals. As a function of predeterminable data, the on-board electrical system control device closes the connection between the two batteries and after being switched off enters a “sleep mode”.

Abstract: A two-battery on-board electrical system in a motor vehicle is disclosed, in which an on-board electrical system control unit is disposed between the batteries, and one battery is used primarily to supply the usual consumers while the other is used primarily to supply the starter. The on-board electrical system control unit 16 includes an on-board electrical system module, which performs the requisite reverse switching operations and has one further terminal, by on-board electrical system components required for starting an operation can be supplied with voltage. These on-board electrical system components are supplied at maximum priority, and if the supply battery is too greatly discharged are jointly supplied by both batteries, but it is nevertheless assured that during the starting process the other on-board electrical system components are not connected to the starter battery.

Abstract: A power supply for a motor vehicle includes an additional voltage storage associated with the starter and the starter is separated from the rest of the vehicle supply system during the starting process by a charging/separating module. Since different variables of the vehicle supply system are supplied to this charging/separating module and corresponding measurements and detection take place within this module, the charging/separating module itself switches off or switches over in a manner which is optimally adapted to requirements.Since the voltage storage associated with the starter and the rest of the vehicle supply battery can be operated completely independently from one another, they can be freely selected based on requirements (starting or buffering). A particularly reliable and safe charging of this voltage storage is ensured at a reduced nominal voltage of the voltage storage, also designated as starter storage.

Abstract: The device for energizing a heating element of a window pane from a direct current network of a motor vehicle includes a converting device for converting the d.c. voltage of the direct current network into an alternating current voltage of a predetermined frequency and a resonant circuit connected to the output of the converting device having a Q-factor high enough to produce a low number of harmonics in operation. The resonant circuit has a resonant frequency corresponding to that of the alternating current voltage. The heating element is a part of a resistance of the resonant circuit. The converting device can include a control circuit for producing alternating control signals, a base driving circuit controlled by the control signals and having two outputs connected respectively to a base of a switching transistor. The device can also include a protecting circuit for picking up energy during opening of the respective switching transistors and returning the picked-up energy to the d.c. network.

Abstract: Disclosed is a device for and a method of applying output voltage from a power generator to a heating resistor in a motor vehicle. During the standstill condition of the vehicle the heating resistor is connected directly to the generator and a power supply network connected parallel to the terminals of a battery, is disconnected from the generator. The output voltage of the generator is regulated to increased values to achieve a higher efficiency in the heating resistor. During the travel of the motor vehicle, the heating resistor is connected in series with the power supply network and a regulated voltage from the power generator is applied across the series connection. The output voltage is regulated such that a nominal voltage is maintained at the power supply network. The switchover between the standstill and running operational conditions is provided by two switching devices which are controlled by a control device in dependency on operational conditions of the motor vehicle.

Abstract: Faulty excitation of the generator-regulator unit in the electrical system of a motor vehicle with resultant changes in the regulator output is indicated by the lighting of a light-emitting diode connected between the ignition switch and a Zener diode furnishing a constant reference voltage. A voltage divider is connected from the ignition switch to the negative battery terminal. One voltage divider tap is connected to the regulator input. When the regulator is underexcited, the voltage drop across the LED is sufficient to cause it to light. Alternatively, a first LED can be provided for indicating underexcitation of the generator and a second one for indicating overexcitation. For this purpose, the first LED is connected between the ignition switch and the regulator input terminal, while the second one is connected between the Zener diode and the regulator input terminal.