Abstract: The invention relates to a climate control system for the interior of a motor vehicle, having a blower regulator, heating control unit or brushless blower motor, as well as function components such as operating elements, sensors, clocking valves and adjusting drive mechanisms, which are connected to one another and to the vehicle battery via connecting lines and to which the information required to operate the blower regulator, heating control unit or brushless blower motor are transmitted.

Abstract: A combined motor vehicle system has two vehicle networks having different supply voltages in which transmitting and receiving devices may exchange signals, regardless of their belonging to one or the other vehicle network, over a common bus conductor using uniform dominant and recessive data signals.

Abstract: A power MOS transistor having a PMT chip located in a transistor housing in which the temperature of the transistor barrier junction is monitored is described. Protection of the PMT chip against overload and permanent damage is guaranteed without negatively affecting its switching function in that a protective circuit is provided in the transistor housing which directly measures the temperature of the transistor barrier junction using a temperature measuring element, and when a predefined or predefinable limit barrier junction temperature is reached reduces the drain current and thus the power loss of the PMT chip, the temperature measuring element being integrated in the PMT chip or accommodated in the transistor housing together with the protective circuit as an additional chip.

Abstract: A protective circuit for a series circuit of a power semiconductor and an inductive load, to which a freewheeling circuit of a freewheeling diode and a reverse polarity protection semiconductor switch connected in series is connected in parallel. The power semiconductor output stage may be switched on and off depending on a predetermined setpoint value with a pulse-width modulated control signal and the reverse polarity protection semiconductor switch may be made non-conducting via a charging pump when the polarity of the supply voltage is reversed.

Abstract: A power output circuit having a pulse-width modulation generator and an upstream closed-loop control circuit which switches the pulse-width modulation generator and the power output stage to a permanently open mode, a PWM mode having pulse-width-modulated pulses, and a permanently closed mode as a function of a preset external setpoint, an actual value of the power output stage, and a reference voltage derived from the supply voltage. High power loss and high EMC in the full-load threshold region are avoided by prematurely switching from the PWM mode to the permanently closed mode as a function of a preset setpoint and the supply voltage, and returning to the PMW mode with a hysteresis of these values.

Abstract: In a protective circuit for a field-effect transistor which has at least drain-, source- and gate-terminals and is operated as a power switch, overloading of the FET is prevented in case of a power supply voltage of inverted polarity in that the switching voltage is able to be supplied to the gate terminal as a driving voltage via a charge pump. The charge pump is powered via a suitable circuit (e.g., a Graetz bridge rectifier) independently of the polarity of the applied power supply voltage. In case of incorrect polarity of the power supply voltage, the charge pump is driven to output a driving voltage via a suitable circuit (e.g., a diode connected to the base terminal).

Abstract: An electronic control circuit for controlling an electromagnetic valve having an armature, in particular for a heating and/or air-conditioning system in a motor vehicle, has an electronic switching element in series with the coil of the valve and is characterized in that the switching element controls the valve voltage (or the valve current) applied to the coil so that the valve voltage reaches a first value when the valve is switched on; then the valve voltage is reduced to a second value which is lower than the first value; and thereafter the valve voltage assumes a third value which is greater than the second value and represents a holding voltage for holding the armature in its switched-on position.

Abstract: An electric heater for a motor vehicle uses heat generated by power semiconductors as the heat source. The heat output by the power semiconductors is used directly for heating. The power semiconductors are regulated by circuit regulators to be able to adjust the heating power continuously. In addition, switching devices are provided which interrupt or shut down the respective branch circuits individually in the event of short circuits in the power semiconductors.

Abstract: A power output circuit having a pulse-width modulation generator and an upstream closed-loop control circuit which switches the pulse-width modulation generator and the power output stage to a permanently open mode, a PWM mode having pulse-width-modulated pulses, and a permanently closed mode as a function of a preset external setpoint, an actual value of the power output stage, and a reference voltage derived from the supply voltage. High power loss and high EMC in the full-load threshold region are avoided by prematurely switching from the PWM mode to the permanently closed mode as a function of a preset setpoint and the supply voltage, and returning to the PMW mode with a hysteresis of these values.

Abstract: An electric heater for a motor vehicle uses heat generated by power semiconductors as the heat source. The heat output by the power semiconductors is used directly for heating. The power semiconductors are regulated by circuit regulators to be able to adjust the heating power continuously. In addition, switching devices are provided which interrupt or shut down the respective branch circuits individually in the event of short circuits in the power semiconductors.