Patent ID: 8196566

Claim:
A voltage generator mountable on a vehicle comprising: a coil configured such that an energization current having a target current value flows through the coil; a resistor coupled to the coil; a current value set means for determining, based on an operating condition of the vehicle, whether a predetermined set condition is true or false, the current value set means setting the target current value of the energization current to a first current value when the set condition is false, the current value set means setting the target current value of the energization current to a second current value less than the first current value when the set condition is true; a current value measurement means for measuring an actual current value of the energization current flowing through the coil, based on an amplified voltage across the resistor; a switch means for determining whether the actual current value measured by the current value measurement means is less than the target current value set by the current value set means, the switch means allowing the energization current to flow through the coil when the measured actual current value is less than the set target current value, the switch means preventing the energization current from flowing through the coil when the measured actual current value is equal to or greater than the set target current value; an output voltage generating means having a capacitor and for generating an output voltage by charging the capacitor by counterelectromotive force produced in the coil; a voltage value measurement means for measuring a voltage value of the output voltage; a switch control means for determining whether the voltage value measured by the voltage value measurement means is less than a predetermined reference voltage value, the switch control means enabling the switch means when the measured voltage value is less than the reference voltage value, the switch control means disabling the switch means when the measured voltage value is equal to or greater than the reference voltage value, and a switching device coupled between a positive terminal of the capacitor and an injector coil of an internal combustion engine of the vehicle to selectively apply the output voltage to the injector coil; wherein the set condition includes a drive interval condition, wherein the drive interval condition becomes true when a drive interval at which a fuel injector of the vehicle is driven is equal to or greater than a predetermined time period, wherein the drive interval condition becomes false when the drive interval is less than the predetermined time period, and wherein the drive interval is a time period from when the fuel injector is opened to when the fuel injector is reopened.