Abstract: A method is described for determining the resistance temperature characteristic of a ceramic glow plug, wherein the glow plug is heated at a specified power, wherein before the heating it is first determined whether the glow plug is an aged glow plug, and then, if the glow plug has not been detected as an aged glow plug, the glow plug is heated at a first specified power and the resistance value thereby achieved is assigned to a temperature that is anticipated to be the final temperature when heating a factory-outlet glow plug at this first power, or if the glow plug has been detected as an aged glow plug, the glow plug is heated at a reduced power which is smaller than the first power, and the resistance value achieved thereby is assigned to the same temperature that is also anticipated when heating a factory-outlet glow plug at the first power.

Abstract: An electric heating device includes a housing with a partition wall which separates a connection chamber from a heating chamber for emitting heat. At least one heating assembly housing projects from the partition wall in the direction of the heating chamber. The heating assembly housing supports at least one PTC element and strip conductors in an electrically insulated manner A housing wall projecting from the partition wall and delimiting the connection chamber and/or the heating chamber and/or the heating assembly housing is connected to the partition wall by material bonding, which may be by induction soldering. Also disclosed is a method of making an electric heating device.

Abstract: A method for detecting glow plug replacement or an aging glow plug. The glow plugs are heated and monitored. When a threshold value is reached for a first glow plug, a first value of a temperature-dependent variable is measured for all other glow plugs and is stored as reference values associated with the first glow plug. This process is repeated until reference values associated with each glow plug have been determined and stored for each glow plug. The process is repeated to determine a set of comparative values. The comparative values are compared with the reference values. A deviation of a comparative from a reference value of less than a specified tolerance value is considered an agreement. The inventive process concludes which of the glow plugs of the engine are unaltered and which have a resistance-temperature characteristic that has been altered to an extent indicating replacement, aging or a defect.

Abstract: A PTC heating assembly includes a heating cell comprising a PTC element and conductor elements electrically abutting the PTC element. The heating cell is accommodated in a heater housing. The heater housing is manufactured with undersize relative to the heating cell so that the heating cell, after insertion into the heater housing, is held under pretension between mutually opposing walls of the heater housing. Accordingly, in the method according to the invention, the heater housing is elastically widened when the heating cell is inserted into the heater housing.

Abstract: A method is described for determining the resistance temperature characteristic of a ceramic glow plug, wherein the glow plug is heated at a specified power, wherein before the heating it is first determined whether the glow plug is an aged glow plug, and then, if the glow plug has not been detected as an aged glow plug, the glow plug is heated at a first specified power and the resistance value thereby achieved is assigned to a temperature that is anticipated to be the final temperature when heating a factory-outlet glow plug at this first power, or if the glow plug has been detected as an aged glow plug, the glow plug is heated at a reduced power which is smaller than the first power, and the resistance value achieved thereby is assigned to the same temperature that is also anticipated when heating a factory-outlet glow plug at the first power.

Abstract: A method for detecting glow plug replacement or an aging glow plug. The glow plugs are heated and monitored. When a threshold value is reached for a first glow plug, a first value of a temperature-dependent variable is measured for all other glow plugs and is stored as reference values associated with the first glow plug. This process is repeated until reference values associated with each glow plug have been determined and stored for each glow plug. The process is repeated to determine a set of comparative values. The comparative values are compared with the reference values. A deviation of a comparative from a reference value of less than a specified tolerance value is considered an agreement. The inventive process concludes which of the glow plugs of the engine are unaltered and which have a resistance-temperature characteristic that has been altered to an extent indicating replacement, aging or a defect.

Abstract: The invention relates to a heating device for heating the interior of a motor vehicle, comprising a plurality of heating modules arranged in at least one heating unit, each heating module comprising at least one heating resistor, at least one heat exchanger configured for delivering heat generated by the heating resistor to an airflow, and a rectangular frame surrounding the at least one heating resistor and the at least one heat exchanger, each frame having openings in opposed frame legs, wherein in the at least one heating unit the frame legs, comprising openings, of adjacent heating modules face one another and electrical connection elements reaching through the openings electrically connect the heating modules to one another.

Abstract: The invention relates to a heating device for heating the interior of a motor vehicle, comprising a plurality of heating modules arranged in at least one heating unit, each heating module comprising at least one heating resistor, at least one heat exchanger configured for delivering heat generated by the heating resistor to an airflow, and a rectangular frame surrounding the at least one heating resistor and the at least one heat exchanger, each frame having openings in opposed frame legs, wherein in the at least one heating unit the frame legs, comprising openings, of adjacent heating modules face one another and electrical connection elements reaching through the openings electrically connect the heating modules to one another.