Disclosed is a method for controlling a DC-DC voltage converter for driving with current at least one fuel injector of a motor-vehicle internal combustion engine. The method includes, when the transistor is switched from the off state to the on state, triggering a counter for measuring time, and, if at the end of a preset time called the “observation” time, the amplitude of the peak current has not reached its maximum value, steps of commanding that transistor so that the transistor switches from the on state to the off state, of keeping the transistor in the off state for a preset time called the “cooling time”, and of commanding the transistor so that the transistor switches to the on state at the end of the cooling time.

Method for controlling a fuel injector with a solenoid actuating a needle opening the injector and a spring returning the needle to the closed position. A controller, powering the solenoid, provides a first potential connected to a first transistor's drain, the source of the first transistor connected to the first diode's anode, the cathode of the first diode connected to a second diode's cathode, to a first connector of the solenoid and to the source of a second transistor. The drain of a second transistor is connected to a second potential, the second diode's anode being connected to ground, the second potential being connected to ground via a capacitance and to the cathode of a third diode, the third diode's anode being connected to a second connector of the solenoid and to the drain of a third transistor, the source of the third transistor being connected to ground.

Disclosed is a method for controlling a fuel injector provided with a solenoid for actuating a needle which opens the injector and with a spring for returning the needle to the closed position. The solenoid is supplied with power by a controller including a first potential and a second potential, a first diode and a second diode, a first transistor, a second and a third transistor which is controlled so as to generate various currents using the potentials.

In a current-driving of a fuel injection valve to inject fuel through a single injection or a multi-stage injection, an energization time correction amount is calculated by performing area correction on a current flowing through the fuel injection valve. The single injection is switched to the multi-stage injection when the single injection is consecutively performed under a predetermined condition.

An injection control device includes: a booster circuit that boosts a battery voltage; a boosting control unit that performs boosting control on the booster circuit; a charge control setting unit that sets a charge prohibition time of the booster circuit for the boosting control unit; and a maximum time specification unit that specifies a maximum valve-closing detection time based on a valve-closing detection time.

An injection control device opens and closes a fuel injection valve by driving the fuel injection valve with a current to control fuel injection to an internal combustion engine. The injection control device includes: a booster circuit that boosts a battery voltage; a boosting control unit that performs boosting control on the booster circuit; and a charge control setting unit that sets charge permission or charge prohibition for the booster circuit to the boosting control unit.

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.

An electromagnetic valve driving device which drives a fuel injection valve having a solenoid coil, includes: a regenerative switching element disposed between a first end portion of the solenoid coil and the ground; and a control unit configured to control the regenerative switching element to be in an ON state or an OFF state, wherein the control unit includes: a voltage detection unit configured to detect a voltage of the first end portion of the solenoid coil; and an abnormality detection unit configured to detect an abnormality of the regenerative switching element on the basis of the voltage detected by the voltage detection unit.

An electromagnetic valve driving device that drives an electromagnetic valve for injecting a fuel, includes: a first charging route that charges a bootstrap capacitor from a battery without intervention of a boost circuit; a second charging route that charges the bootstrap capacitor from the boost circuit; and a switching control unit that switches a charging route for charging the bootstrap capacitor to the first charging route or the second charging route.

An injection controller includes a control IC outputting an energization instruction signal to apply a peak current to a fuel injection valve (i.e., an instruction TQ), and a current monitor unit detecting an electric current flowing in the fuel injection valve. The control IC corrects an output OFF time of the energization instruction signal based on a difference between (i) an integrated current of an ideal current profile which serves as a target current before reaching the peak current and (ii) an integrated current of an energization current in the fuel injection valve detected by the current monitor unit (i.e., an effective TQ).