Abstract: To provide a fuel injection device for controlling a fuel injection valve including a solenoid and a magnetostrictive element to generate a drive force for driving the fuel injection valve, the fuel injection device including: a solenoid power source (31) for driving the solenoid, a solenoid drive circuit (10) adapted to control the electrification to the solenoid by the solenoid power source (31), a plurality of magnetostrictive element driving power sources (32, 33) for driving the magnetostrictive element, and a magnetostrictive element drive circuit (20) adapted to control the electrification to a magnetostrictive coil of the magnetostrictive element by the magnetostrictive element driving power sources.

Abstract: An actuator driving circuit for driving an electromagnetic actuator, includes a boosting circuit which boosts a source voltage, and a boosted voltage controller which is connected to an output terminal of the boosting circuit, i.e., the downstream of the boosting circuit, to control a boosted voltage generated by the boosting circuit.

Abstract: To provide a fuel injection device for controlling a fuel injection valve including a solenoid and a magnetostrictive element to generate a drive force for driving the fuel injection valve, the fuel injection device including: a solenoid power source (31) for driving the solenoid, a solenoid drive circuit (10) adapted to control the electrification to the solenoid by the solenoid power source (31), a plurality of magnetostrictive element driving power sources (32, 33) for driving the magnetostrictive element, and a magnetostrictive element drive circuit (20) adapted to control the electrification to a magnetostrictive coil of the magnetostrictive element by the magnetostrictive element driving power sources.

Abstract: A power supply boost control device and a fault location identification and judgment method for the power supply boost control device of this invention comprise a step of judging whether a power supply relay has a turn-on fault, a precharge circuit has a turn-on fault, or the power supply relay has a turn-on fault; second judgment unit is comprised for judging whether a boosting prohibit function is faulty, or the precharge circuit has a turn-off fault, or the precharge circuit has a turn-off fault; and third judgment unit is comprised for judging, based on the judgment result of the first voltage judgment unit, whether or not the power supply relay has a turn-off fault.

Abstract: An excitation control circuit for suitably exciting a solenoid while current consumption and heating are effectively reduced. The control circuit has a driving circuit for driving a coil of a solenoid in response to a pulse signal supplied from an external device; a counter-electromotive force absorbing circuit, inserted in a path of a return current of the coil, for absorbing counter-electromotive force produced by the coil; and a return current circuit, connected in parallel to the counter-electromotive force absorbing circuit, for intermittently bypassing the return current. The return current circuit may have a field effect transistor switched on according to a signal for defining the timing of bypassing the return current, where the current path of the transistor is connected between a positive electrode and a negative electrode of the coil.

Abstract: A power supply boost control device and a fault location identification and judgment method for the power supply boost control device of this invention comprise a step of judging whether a power supply relay has a turn-on fault, a precharge circuit has a turn-on fault, or the power supply relay has a turn-on fault; second judgment unit is comprised for judging whether a boosting prohibit function is faulty, or the precharge circuit has a turn-off fault, or the precharge circuit has a turn-off fault; and third judgment unit is comprised for judging, based on the judgment result of the first voltage judgment unit, whether or not the power supply relay has a turn-off fault.

Abstract: An excitation control circuit for suitably exciting a solenoid while current consumption and heating are effectively reduced. The control circuit has a driving circuit for driving a coil of a solenoid in response to a pulse signal supplied from an external device; a counter-electromotive force absorbing circuit, inserted in a path of a return current of the coil, for absorbing counter-electromotive force produced by the coil; and a return current circuit, connected in parallel to the counter-electromotive force absorbing circuit, for intermittently bypassing the return current. The return current circuit may have a field effect transistor switched on according to a signal for defining the timing of bypassing the return current, where the current path of the transistor is connected between a positive electrode and a negative electrode of the coil.