Abstract: A drive circuit for an electrostrictive element actuator for a fuel injection apparatus of a diesel engine. The drive circuit has a condenser adapted to be charged with electric charges generated by the electrostrictive element actuator; a combination of an electric charge transferring switching element and a rectifier element for becoming conductive in a first period and charging electric charges generated by the electrostrictive element actuator to the condenser; and a combination of an electric charge returning switching element and a rectifier element for becoming conductive in a second period, other than the first period, and returning electric charges stored in the condenser to the electrostrictive element actuator.

Abstract: A device for measuring the flow rate of air includes an electric heater arranged in a path of the air flow and a temperature compensation resistor arranged at a distance from the heater in the path of the air flow, the resistance of the resistor being changed according to the temperature of the air. A selective current supply unit supplied the heater with a current having a current value selected from one of two, large and small, current values. A temperature selection unit selects a plurality of temperature values of the electric heater according to the change of the resistance of the temperature compensation resistor. A current value switching unit switches the current level of the selective current supply under the condition that one of the selected temperature values is attained or maintained.

Abstract: A piezoelectric element driving device applicable to an actuator portion of a fuel injection valve for an internal combustion engine, including a first switching unit, operating to generate a first set voltage in response to a first signal transmitted at predetermined intervals, and a second switching element, operating to generate a second set voltage in response to a second signal transmitted after a predetermined period of time upon completion of the operation of the first switching element. There are provided a unit for regulating the first and second set voltages by means of rectifying devices arranged between the first and second switching elements and a piezoelectric element, and a resonance coil connected between connecting points of the first and second switching elements and the rectifying devices.

Abstract: An ignition device for an internal combustion engine has a DC power source, first and second switching elements, a control signal generator for the switching elements, an ignition coil, and spark gaps. A first part of a primary coil of the ignition coil, a capacitor, the DC power source, and the first switching element form a closed circuit. A second part of the primary coil and the second switching element form another closed circuit. The signal generator generates ON signals for alternately turning on the first and second switching signals at predetermined timings based on an ignition command signal. The ignition performance of this ignition device for an internal combustion engine is improved.