VERFAHREN UND VORRICHTUNG ZUR ERMITTLUNG EINES MIT EINER DITHERFREQUENZ ÜBERLAGERTEN PWM-SIGNALS ZUR STEUERUNG EINES MAGNETVENTILS

摘要

A PWM signal on which a dither signal is superimposed is used for adjusting a central position when controlling a solenoid valve. To improve this type of control process in which the amplitude of the dither signal depends on the current of the solenoid valve and thus on the PWM signal, the PWM signal and the dither signal are generated in a computer unit independently of the power regulation process. Forming the signals separately has the advantage of generating a constant amplitude for the dither signal each time a triggering signal is generated for the solenoid valve such that the armature of the solenoid valve can oscillate specifically about the central position and thereof at constant small vibrations. This allows frictional forces to be reliably reduced and the solenoid valve to be switched more rapidly while the load on the main computer is reduced.