Patent ID: 8352088

Claim:
A system for optimizing power to a movable core within a valve, said system comprising: a controller unit having a pair of valve control outputs for providing a valve control signal; and a valve comprising a pair of valve control inputs, a solenoid, and a core operable between a first position and a second position; wherein said pair of valve control inputs is connected to said solenoid and to said pair of valve control outputs; wherein said controller unit defines an inrush DC voltage level signal for forcing said core into said second position and a hold DC voltage level signal for retaining said core in said second position and a zero voltage signal for moving said core to said first position; wherein said controller unit, in said first position of said core, provides said valve control signal with said hold DC voltage level, measures a first self inductance representing said core in said first position, and provides said valve control signal with said inrush DC voltage level signal for forcing said core from said first position to said second position; wherein said controller unit subsequently provides said valve control signal with said hold DC voltage level for retaining said core in said second position; wherein said controller unit measures, in said second position of said core, a second self inductance representing said core in said second position; wherein said controller unit, in said second position of said core, while providing said valve control signal with said hold DC voltage level, gradually decreases said hold DC voltage level and measures a third self inductance representing the actual physical position of said core; wherein said controller unit determines, on the basis of one of said first and second self inductances in comparison with said third self inductance, whether said core is in said first or second position; wherein, on the basis of said comparison, said controller unit applies said gradually decreased hold DC voltage level for retaining said core in said second position if said core is in said second position; and wherein said controller unit provides said inrush DC voltage level signal, said hold DC voltage level and said zero voltage signal to said valve by supplying from said pair of valve control outputs a pulsed DC control signal to said pair of valve control inputs, said pulsed DC signal defining a maximum voltage in the range of 25V to 45V, a minimum voltage in the range of 0V to 5V, and a controller unit output pulse width in the range of 100 μs to 0.1 s, said controller unit output pulse width defining a first part having said maximum voltage and a second part having said minimum voltage, and wherein said pulsed DC signal constitutes said inrush DC voltage level signal by having said first part longer than or equal to said second part during a period in the range 10 ms to 1 s, and constitutes said DC hold voltage level by having said first part shorter than said second part.