Driving glow plug for igniting vehicle heater involves applying voltage to bring plug close to ignition temperature at start of pilot glow phase until percentage of optimal resistance reached

The method involves applying a clocked supply voltage to the glow plug and evaluating a resistance measured at the plug. The glow plug is operated with a voltage sufficient to bring it close to the ignition temperature at the start of each subsequent pilot glow phase until a defined percentage of an optimal resistance determined in the first pilot glow phase is reached. The method involves applying a clocked supply voltage to the plug (6) and evaluation of a resistance measured at the glow plug. The glow plug is driven with a constant electrical power that produces a typical radiation temperature for the glow plug at least during the end phase of a pilot glow phase, the glow plug resistance is measured at the end of the first pilot glow phase and the applied power is regulated by clocking at constant resistance in a following ignition phase. The glow plug is operated with a voltage sufficient to bring it close to the ignition temperature at the start of each subsequent pilot glow phase until a defined percentage of the determined optimal resistance is reached. Die Erfindung betrifft ein Verfahren zum Ansteuern eines Glühstifts zum Zünden eines Fahrzeugheizgeräts nach dem Hauptpatent (Deutsche Patentanmeldung Nr. 19936729.9-23), wobei zu Beginn der Vorglühphase der Glühstift mit einer konstanten Spannung U¶12¶ betrieben wird, die dazu dient, den Glühstift schnell in die Nähe der Zündtemperatur zu bringen, bis ein vorgegebener Prozentsatz des Werts des Widerstands des Glühstifts erreicht ist, der in einer vorausgehenden Vorglühbeginnphase als optimal ermittelt wurde.