An injection control device includes a control IC that obtains, as sample data, a time change of a voltage generated when a fuel injection valve is driven, and determines a valve closing timing at which injection of fuel from the fuel injection valve is stopped by calculating a degree of variation from the sample data of the voltage. Further, the control IC changes the calculation of the degree of variation when a predetermined condition is satisfied.

An injection control device includes: an area correction unit that calculates an energization time correction amount when executing a current drive of a fuel injection valve to inject a fuel from the fuel injection valve; a charging circuit that applies an electric power from the charging unit to the fuel injection valve; and a charge amount determination unit for determining the charge amount of the charging unit. The area correction unit changes the area correction control based on a determination result of the charge amount determination unit.

An injection control device includes: a fuel injection quantity command value output unit that outputs a command value for a fuel injection quantity of a fuel injection valve; a fuel injection quantity correction unit that calculates an air-fuel correction amount and corrects the command value for the fuel injection quantity; and a controller that executes current control on the fuel injection valve. The controller executes current area correction by calculating an area correction amount for an energization time. The injection control device further includes a learning controller that stops the air-fuel learning.

Disclosed is a method for triggering the switching of a switching transistor of a quasi-resonant DC-to-DC voltage converter to the on state. The method includes the steps of phase-shifting the drain voltage of the transistor by a predetermined temporal phase-shift value that corresponds to the difference between the duration of a quarter of the period of the damped sinusoidal oscillation generated when the transistor is switched off and the period of time that elapses between the command to switch the transistor to the on state and the transistor actually conducting, and, when the phase-shifted voltage is equal to the reference voltage, triggering the command to switch the transistor to the on state such that the transistor starts conducting at the time when the value of the drain voltage is at a minimum.

A DC-DC converter includes an output-side storage capacitor arrangement which has a parallel circuit formed of an electrolytic capacitor, a ceramic capacitor and a circuit arrangement. The circuit arrangement has a series circuit formed of a hybrid electrolytic capacitor and a suppressor diode as well as a resistance connected in parallel with the hybrid electrolytic capacitor.

An injection control device controls the opening and closing of a fuel injection valve by performing peak current drive and constant current drive and controls injection of fuel from the fuel injection valve to an internal combustion engine. The injection control device includes a preheat current energization control unit configured to, when a temperature of a solenoid coil of the fuel injection valve prior to starting the internal combustion engine is lower than a predetermined temperature, energize the fuel injection valve with a preheat current having an output density that causes the temperature of the solenoid coil to increase, the preheat current being within a range that maintains the fuel injection valve in a valve closed state, and when the temperature of the solenoid valve increases to or above the predetermined temperature, stop the energization of the fuel injection valve with the preheat current.

A drive circuit is controlled when power is interrupted. When power is turned off, a main power supply is switched to a sub-power supply, and a residual charge of a step-up circuit is lowered to a drive voltage of a drive circuit using a step-down circuit is used as the sub-power supply.

An injection control device includes: a boost controller performing a boost switching control of a boost switch to charge a boost capacitor and supplying a boost power from a battery power supply; a boost voltage monitor monitoring the boost voltage; and a boost monitor timing controller setting a section from a predetermined time after an on-edge of the boost switch to an off-edge timing in a section monitor mode as a boost monitor section. The boost controller stops boosting by stopping the boost switching control when the boost voltage is equal to or higher than a boost stop threshold value in the boost monitor section.

An injection control device includes: a boost controller charging a boost capacitor by performing a boost switching control of a boost switch, and supplying a boost power from a battery power source; and a boost voltage monitor monitors a boost voltage. The boost controller measures a number of times of when the boost voltage becomes equal to or higher than a predetermined value due to a boost current flowing into the boost capacitor, causing a jump of the boost voltage during a time between a start and stop of boosting, and determines deterioration of the boost capacitor by comparing the measured number of times (i.e., the number of jumps) with a predetermined number of times.

There is provided a transformation control device of a transformation chopper circuit that transforms an input by turning on and off a current using a switch and outputs the transformed input. The transformation control device controls at least an ON/OFF state of a main switch by acquiring an output voltage of the transformation chopper circuit in a case where the main switch is in an ON state, the main switch being turned on in a case where energy is accumulated in an inductor.