An injection control device controls a drive of a solenoid in a high pressure pump for pressurizing fuel to an internal combustion engine. The injection control device includes a transistor on an upstream side of a power supply path from a direct current power supply line to the solenoid and a transistor provided on a downstream side of the power supply path. The injection control device further includes a diode at a position between an upstream terminal of the solenoid and ground, a transistor arranged in parallel with the diode, and a drive controller. The drive controller drives the solenoid to an open position by switching ON the transistors on the upstream and downstream sides of the power supply path.

An interface circuit assembly for use with an electronic control unit and oxygen sensor of an internal combustion engine. The assembly includes an input port coupled to receive a signal from the oxygen sensor and a processing unit coupled with the input port. The processing unit increases the signal to an output voltage as a function of hydrogen being provided to the internal combustion engine. An output port is coupled with the processing unit and provides the output voltage to the electronic control unit.

An input protection circuit (200) and associated method are disclosed for protecting a circuit input (V.sub.INP) from positive and negative overvoltages at an input voltage (V.sub.IN) with a high-voltage PMOSFET (P1) having a gate, a drain connected across a zener diode (ZD1) to the gate, and a source connected to receive an input voltage; a blocking FET (N1) having a gate connected to a power supply voltage, a drain connected across a zener diode (ZD2) to the power supply voltage, and a source connected to the gate of the high-voltage PMOSFET; a high-voltage NMOSFET (N3) having a gate connected to the power supply voltage, a source providing the protected output voltage and connected across a zener diode (ZD3) to the gate, and a drain connected to a source follower node and a level shifter circuit (214) connected between the drain of the high-voltage PMOSFET and the source follower node.

A first high side switch is configured to connect and disconnect a first reference potential to and from a first node, the first node configured to be electrically connected to a second node and a first end of a first inductor coil of a fuel injector of a cylinder and a first end of a second inductor coil of an oil control valve of the cylinder. A second high side switch is configured to connect and disconnect a second reference potential to and from the second node. A first low side switch is configured to connect and disconnect a ground reference potential to and from a second end of the second inductor coil of the oil control valve. A second low side switch is configured to connect and disconnect the ground reference potential to and from a second end of the first inductor coil of the fuel injector.

An injection control device controls a solenoid in a fuel injection valve. The injection control device includes a transistor on an upstream side of a first power supply path to the solenoid and a transistor on an upstream side of a second power supply path to the solenoid. The injection control device has another transistor with a body diode arranged in parallel at a position on the first power supply path between the first transistor and an upstream terminal of the solenoid. The injection control device also includes a transistor on the downstream side of the first and second power supply paths. A drive controller in the injection control device drives the solenoid to an open position by switching ON the transistor on the downstream side and the transistor on the upstream side of the first power supply path or the transistor on the upstream side of the second power supply path.

An input protection circuit (200) and associated method are disclosed for protecting a circuit input (V.sub.INP) from positive and negative overvoltages at an input voltage (V.sub.IN) with a high-voltage PMOSFET (P1) having a gate, a drain connected across a zener diode (ZD1) to the gate, and a source connected to receive an input voltage; a blocking FET (N1) having a gate connected to a power supply voltage, a drain connected across a zener diode (ZD2) to the power supply voltage, and a source connected to the gate of the high-voltage PMOSFET; a high-voltage NMOSFET (N3) having a gate connected to the power supply voltage, a source providing the protected output voltage and connected across a zener diode (ZD3) to the gate, and a drain connected to a source follower node and a level shifter circuit (214) connected between the drain of the high-voltage PMOSFET and the source follower node.

A method of controlling an injector driving circuit that may include a first field effect transistor (FET) that opens and closes a driving power supply to an injector, a second FET having a pulse width modulation control function for supplying a starting current to the injector to open a valve and then supplying a driving current for maintaining an opening driving state to the injector, and a Zener diode. The method may include increasing a valve opening torque to open the injector via turning ON both the first and second FET to obtain a maximum current during a cold start or when an injector valve sticks, turning OFF the second FET before closing the injector, and preventing damage to the Zener diode due to a back electromotive voltage from the injector provided when the valve is closed via turning OFF the first FET after a predetermined amount of time elapses.

This fuel includes: a first switching element disposed between a booster circuit boosting a battery power and one end of a solenoid; a second switching element disposed between a battery and one end of the solenoid; a third switching element disposed between the other end of the solenoid and a ground; a fourth switching element disposed between one end of the solenoid and a ground; and a control unit configured to control open/closed states of the first switching element, the second switching element, the third switching element, and the fourth switching element. The control unit is configured to open the fourth switching element during a valve closing detection period of detecting closing of a fuel injection valve and to detect the closing of the fuel injection valve on the basis of a change in voltage of the other end of the solenoid.

An electromagnetic valve drive device includes: a state detection unit configured to detect an on-state or an off-state of a first switch and a second switch forming a boosting circuit; a boosting control unit configured to control a boosting operation, by performing a synchronous rectification control on switching of the first switch and the second switch, depending on the state of the first switch or the second switch detected by the state detection unit; and a drive circuit configured to drive an electromagnetic valve by supplying a voltage boosted by the boosting operation to the electromagnetic valve.

A circuit arrangement for driving an inductive load is connectable to a load terminal. A first MOS field effect transistor is connected between a terminal for a high potential of a first supply voltage source and the load terminal. A series connection with a freewheeling diode and a second MOS field effect transistor has its freewheeling diode connected between the load terminal and a second terminal for a low potential of the first supply voltage source. The freewheeling diode has its cathode connected to the load terminal. A series connection with a reverse-biased zener diode and a forward-biased diode is connected between the drain and gate terminals of the first MOS field effect transistor. A first control signal terminal is connected to the gate terminal of the second MOS field effect transistor and via an AND circuit to the gate terminal of the first MOS field effect transistor.