Abstract: An ultrasonic flow meter is disclosed, including a switching unit for switching electrical transmission signals between a signal generator and at least two ultrasonic transducers and for switching electrical reception signal between the transducers and a receiver circuit, wherein the switching unit is coupled to an output terminal of an operational amplifier of the signal generator and to an inverting input terminal of an operational amplifier of the receiver circuit. Furthermore, a method for characterizing an ultrasonic transducer is disclosed, including the step of determining directly from one or more supply current signals for an active component of a signal generator one or more quantities useful for characterizing the transducer. Furthermore, a method for determining the time delay of an ultrasonic signal in a flow path of an ultrasonic flow meter is disclosed, including the step of comparing physically transmitted, delayed and received signals with simulated non-delayed signals.

Abstract: There is disclosed a mechanical-vibration-generating-device for generating a mechanical vibration, the mechanical vibration having a vibration direction.

Abstract: A fuel injection control apparatus is provided with a first valve opening timing determination portion that determines a first valve opening timing on the basis of a collision signal that is included in detected signals of an in-cylinder pressure sensor and indicates a collision between a movable core and a valve element and a second valve opening timing determination portion that determines a second valve opening timing on the basis of another collision signal that is included in the detected signals and indicates a collision between the movable core and a stationary core.

Abstract: A misfire detection apparatus of an internal combustion engine for detecting combustion or a misfire of an air fuel mixture in the internal combustion engine based on an ion current generated at the combustion time of the air fuel mixture. The misfire detection apparatus includes ion current detection means and misfire determination means. The ion current detection means detects the ion current responsive to the amount of ions occurring in a cylinder just after combustion of the air fuel mixture in the cylinder in the internal combustion engine. The misfire determination means calculates a predetermined function based on the ion current detection value and determines that the condition is combustion when the magnitude exceeds a threshold value.

Abstract: A screen printing method and apparatus for printing a circuit pattern corresponding to that of a stencil (4), onto a print-object article (1) placed on an ascendable/descendable positioning stage (2), through moving a squeegee (5a, 5b) horizontally while the squeegee is pushed in on the stencil so that print paste (9) is printed to the article via the stencil. The squeegee is lifted to an extent of a push-in stroke, to which the squeegee has been pushed in on the stencil, and thereafter the article is separated away from the stencil by moving the stage downward. The board is classified into first and second areas (121, 120) where values of opening sizes of the stencil along a squeegee moving direction are smaller than and not smaller than a threshold, and a speed of the squeegee at the first area is made slower than that at the second area.

Abstract: For use in a combustion-powered, fastener-driving tool having a combustion chamber, a source of a combustible fuel, and a switch that must be closed to enable the tool, a fuel system comprises a fuel injector, which includes a normally closed, solenoid-energized valve between the fuel source and the combustion chamber, and an electronic circuit responsive to the switch for energizing the solenoid to open the valve when the switch is closed and for deenergizing the solenoid after a time interval. A resistive-capacitive network defining the time interval includes a first resistor, a second resistor arranged to be selectively connected in parallel therewith, a thermistor connected in parallel therewith, and a variable resistor connected to the parallel resistors. Another network effects a time delay between closure of the switch and energization of the solenoid. Optionally, another network varies the time interval in response to ambient pressure.

Abstract: An improved input circuit for an electronic vehicle speed control unit is disclosed. An ignition current sensor coil is adapted to have a voltage differential signal induced therein each time an ignition pulse is generated by the vehicle engine. Electrical noise signals generated by the vehicle engine appear as common mode signals across the ignition current sensor coil. The ignition current sensor coil is connected at each end to a capacitor, both of which are connected to ground potential. The ends of the ignition current sensor coil are further connected to the inputs of a differential amplifier. The capacitors appear in a series loop with the ignition current sensor coil for the differential voltage signals and, consequently, provide tuning for inductance. However, the capacitors appear in parallel with one another to ground potential with respect to the common mode noise signals, thereby providing high frequency noise rejection for the input circuit.

Abstract: An electronic fuel control system of the type providing fuel delivery controlling signals during the period of time that at least a portion of a controlled signal maintains a preselected relationship with respect to particular value is provided with circuit means for continuously providing a variable correction factor. The injection controlling signal is produced by generating a time varying voltage which varies in a predetermined fashion following the occurrence of a triggering event. The generated voltage signal has a first or correction portion and a second or injection controlling portion. The magnitude of the first portion is modulated as a function of the time elapsed from the most recently to have occurred triggering event to provide accurate information to controllably affect fuel delivery.

Abstract: A fuel control system for an electronically controlled fuel injected internal combustion engine, whereby fuel is injected into the cylinders for a fixed number of degrees with respect to the crankshaft rotation. A trigger pulse is fed into a tachometer circuit (32) giving a DC ramp output with respect to speed. A portion of this ramp signal is fed into a monostable circuit (31) whose output pulse duration is now speed dependent and remains constant in degrees of engine crankshaft as the speed of the crankshaft increases. By adjusting the slope of DC ramp output fed into the monostable circuit (31), the fuel "on" time may be set to any fixed number of engine crankshaft degrees desired for a particular engine.

Abstract: A fuel injection control circuit includes a monostable multivibrator for generating injection valve control pulses. The circuit includes a trigger sub-circuit which controls the switching characteristics of the monostable multivibrator in a well-defined manner which is immune to electrical noise and to voltage fluctuation in the supply lines of the vehicle.