Method for determining the instant when the movable element of a solenoid valve reaches its end position following energization of the solenoid, by means of an analysis of the switching frequence of the solenoid driving current

A method for determining an instant when a movable element of a solenoid valve reaches an end-of-travel position following upon energization of the solenoid, the method comprising:

• said movable element displaced by application to the solenoid of alternating phases at a constant voltage and at a zero voltage in such a way as to give rise to an alternation of phases of charging and discharging of the solenoid corresponding to increases and decreases of current around a substantially constant current value,
• in which the alternating phases at constant voltage and at zero voltage are controlled in such a way that:
• the phase at constant voltage is terminated when the increasing current reaches a pre-set value and the phase at zero voltage is maintained for a fixed time;
• and
• in which the duration of each cycle made up of the aforesaid charging phase and the subsequent discharging phase is constantly monitored and the instant of reaching of the aforesaid end-of-travel position is identified as the instant that separates two successive cycles of charging and discharging that present a difference of duration greater than a pre-set threshold value.

A method for determining an instant when a movable element of a solenoid valve reaches an end-of-travel position following upon energization of the solenoid, the method comprising:

• said movable element displaced by application to the solenoid of alternating phases at a constant voltage and at a zero voltage in such a way as to give rise to an alternation of phases of charging and discharging of the solenoid corresponding to increases and decreases of current around a substantially constant current value,
• in which the alternating phases at constant voltage and at zero voltage are controlled in such a way that:
• both the phase at constant voltage and the phase at zero voltage are terminated when the increasing current or decreasing current reaches a pre-set value;
• and
• in which the duration of each cycle made up of the aforesaid charging phase and the subsequent discharging phase is constantly monitored and the instant of reaching of the aforesaid end-of-travel position is identified as the instant that separates two successive cycles of charging and discharging that present a difference of duration greater than a pre-set threshold value.