Abstract: An electric heating system for motor vehicles including one or several electric heating elements; a control circuit provided for controlling the power dissipated by the heating elements; the control circuit including one or several power semiconductors arranged on a circuit board; the circuit board is by means of a solid matter connection connected by the side facing away from the power semiconductors to a metal plate intended to be mass potential; the metal plate being electrically insulated from conductor paths located on the underside of the circuit board and intended to carry a voltage in relation to the ground potential; the control circuit being arranged in a housing. One or several heat sinks are provided outside the housing. The metal plate is connected with the heat sinks arranged outside the housing by thermally conductive connectors.

Abstract: A method for operating a multi-stage electrical heater comprised of several heating elements. In conventional multi-stage electrical heaters, the resistance value of the individual heating elements scatters. In order that the individual heating elements emit the same power, specifically the required nominal power, despite the scattered resistance values, the voltage on the individual heating elements is separately regulated down to the required nominal power, proceeding from a maximum electrical resistance of the individual heating elements, at which the entire applied operating voltage yields the nominal power of the individual heating elements required for operation.

Abstract: A method and device for controlling the heating of the glow plugs in a diesel engine, wherein the engine temperature is determined, independently of initialization of the engine control system and following a signal for starting the engine, by a sensor communicating with the glow control system. A glow command is generated if the engine temperature is below a predetermined value. Commencement of the heating procedure is automatically determined by the glow control system independently of initialization of the engine control system, and heating of the glow plugs can start prior to completion of initialization of the engine control system. The time required for the completion of initialization of the engine control system can be saved during heating of the glow plugs.

Abstract: Method for heating an electrical heating element, for example, a glow plug for an internal combustion engine, from an initial temperature to the operating temperature. In order to prevent the heating element from overheating in cases where the initial temperature is higher than a set temperature that is normally taken as a basis, the actual initial temperature of the heating element is first determined, and an amount of electrical power depending on the level of the determined initial temperature is supplied to the heating element. In this way, the supplied amount of electrical power is reduced at higher initial temperatures, thus preventing the heating element from becoming overheated to a temperature at which damage can occur.

Abstract: Process and circuit for heating up a glow plug of a given glow plug type in a given arrangement in an internal combustion engine to a predetermined temperature. The power supply voltage is on the glow plug via a measurement resistor (12) and a switch (11). A control and regulation unit (16) taps the voltage drop via the measurement resistor (12) and determines the heat energy supplied to the glow plug therefrom and from the likewise tapped voltage on the glow plug. The signal which occurs on the output (15) of the unit (16) controls the switch (11). After closing the switch (11) the unit (16) supplies the glow plug with heat energy which is added up in the unit (16). As soon as the heat energy which is required for heating up to a predetermined temperature and which is determined beforehand from the known parameters of the glow plug and from the starting temperature is reached, the switch is opened again via the output signal at the output (15).