Abstract: The invention relates to a method for operating a glow plug with the engine running, wherein an effective voltage is generated from a vehicle electrical system voltage by pulse width modulation, the effective voltage is applied to the glow plug and changed as a function of engine parameters, a target value of the effective voltage that is dependent on the engine parameters and to which the effective voltage is changed is specified, a maximum increment for a change of the actual value of the effective voltage in at least one direction is specified, and a change of the actual value in at least one direction to a target value that deviates from the actual value by more than the maximum increment is carried out in several steps. The invention further relates to a controller which carries out such a method during operation.

Abstract: The invention relates to a method for heating a glow plug to a setpoint temperature using a glow program which specifies the course over time of an effective voltage which is generated using pulse width modulation and is applied to heat the glow plug, wherein the glow program is stored in a control device and is provided for the glow plug and other glow plugs of the same model series, the parameters of which match within the scope of manufacturing tolerances. According to the invention, a deviation of a value of a parameter of the glow plug from a nominal value that is typical for a model series is determined, and the glow program is adapted as a function of the deviation. The invention furthermore relates to a glow plug control device for implementing a method of that type.

Abstract: A method for heating a glow plug for a diesel engine to its desired temperature by supplying power to the glow plug in a controlled fashion. During a certain time interval after termination of a previous glow process, a mathematical model is used to determine the values for the supply of power to the glow plug, which includes the values of the actual thermal state of the glow plug, the time elapsed since the end of the previous glow process and the parameters of the diesel engine relevant for a glow process.

Abstract: A method for heating a glow plug for a diesel engine to its desired temperature by supplying power to the glow plug in a controlled fashion. During a certain time interval after termination of a previous glow process, a mathematical model is used to determine the values for the supply of power to the glow plug, which includes the values of the actual thermal state of the glow plug, the time elapsed since the end of the previous glow process and the parameters of the diesel engine relevant for a glow process.