Steuerungssysteme für Kanisterspülsteuerventile

摘要

A purge control valve control system is provided for an internal combustion engine system, comprising: a voltage source having a positive potential and a negative potential; a purge control valve having a solenoid, such solenoid comprising an electrically inductive element, such inductive element having a first terminal coupled to the positive potential of the voltage source; a diode having an anode and a cathode. The control unit includes a transistor having: a control electrode fed by a train of pulses; a first electrode coupled to the negative potential of the voltage source; and a second electrode coupled to a second terminal of the inductive element and to the diode. A train of pulses fed to the control electrode is a pulse width modulated signal and switches the transistor between a conducting condition, wherein current passes between the first electrode and the second electrode, and a non-conducting condition, wherein current is prevented from passing between the first electrode and the second electrode. When the transistor is in the conducting condition current from the voltage source passes through the inductive element and through the first and second electrodes with a potential being produced across the diode to bias the diode to a non-conducting condition and wherein when the transistor switches into the non-conducting condition, energy stored in the inductor when current passes through the inductor during the conducting condition of the transistor, produces a voltage pulse to bias the diode to a conducting condition and such stored energy is dissipated in the inductor as such energy passes as current through the conducting biased diode to the voltage source.