Solenoid valve driver and fuel injection system equipped with the same for compensating lag of operation of solenoid valve

A solenoid valve driver comprising:

• a capacitor in which electric energy is stored which is to be discharged to energize a coil of at least one solenoid valve;
• a charging circuit that charges said capacitor to bring a charged voltage of said capacitor to a target voltage level;
• and
• a controller working to determine a discharge start time that is a time when said capacitor is to be started to be discharged to energize the coil of the solenoid valve and discharge said capacitor when the discharge start time is reached, said controller determining whether said capacitor is in a lack-of-charge state where the charged voltage is lower than the target voltage level or not, when it is determined that said capacitor is in the lack-of-charge state, said controller correcting the discharge start time to advance the discharge start time.

A solenoid valve driver comprising:

• a capacitor in which electric energy is stored which is to be discharged to energize a coil of at least one solenoid valve;
• a charging circuit that charges said capacitor to bring a charged voltage of said capacitor to a target voltage level;
• and
• a controller working to determine a discharge start time that is a time when said capacitor is to be started to be discharged to energize the coil of the solenoid valve and discharge said capacitor when the discharge start time is reached, said controller measuring a value of the charged voltage of said capacitor before being discharged and correcting the discharge start time based on the measured value of the charged voltage.

A fuel injection apparatus comprising:

• an injector equipped with a coil, said injector being opened to spray fuel upon energization of the coil;
• a capacitor in which electric energy is stored which is to be discharged to energize the coil of said injector;
• a charging circuit that charges said capacitor to bring a charged voltage of said capacitor to a target voltage level;
• and
• a controller working to determine a discharge start time that is a time when said capacitor is to be started to be discharged to energize the coil of said injector and discharge said capacitor when the discharge start time is reached, said controller working to perform a sequence of spray operations to spray the fuel from said injector and advance the discharge start time for second or subsequent one of the sequence of spray operations.