Patent ID: 8050010

Claim:
A method for controlling a glow plug associated with a cylinder chamber of a diesel engine, comprising the steps of: driving in an on-off manner, in a period of time, an electronic switch connected essentially in series with the glow plug between terminals of a D.C. voltage supply; sensing a voltage across the glow plug and a current flowing through the glow plug; generating a first analog sense signal that is representative of a first time integral of a sensed current; generating a second analog sense signal that is representative of a second time integral of a sensed voltage; generating a first reference signal having a first analog value corresponding to a first digital control word; generating a second reference signal having a second analog value corresponding to a second digital control word; comparing, while the electronic switch is in an on-state, the first analog sense signal with the first reference signal and the second analog sense signal with the second reference signal; modifying a digital value of the first digital control word and the second digital control word to minimize the difference between the first analog sense signal and the first reference signal, and the difference between the second analog sense signal and the second reference signal; and calculating an average value, of the sensed current over said period of time, as a function of the difference between said first digital control word at a beginning and at an end of the on-state or a conduction time of the electronic switch, and of the sensed voltage over said period of time, as a function of the difference between said second digital control word at the beginning and at the end of the on-state or a conduction time of the electronic switch.