Abstract: In an apparatus for detecting fuel shortage of a general-purpose internal combustion engine connectable to an operating machine to be used as a prime mover of the machine, the engine being supplied with fuel stored in a tank and having an actuator adapted to open and close a throttle valve installed in an air intake pipe so as to achieve a desired engine speed set by an operator, comprising a fuel shortage condition detector adapted to detect whether the engine is in a fuel shortage condition, and an engine stopper adapted to stop the engine when the engine is detected to be in the fuel shortage condition. With this, it becomes possible to detect whether the engine having the electronic governor is in the fuel shortage condition, thereby preventing occurrence of trouble such as afterburning.

Abstract: In an apparatus for controlling an air/fuel ratio of a general-purpose internal combustion engine using mixed fuel containing alcohol and gasoline and operated at a desired engine speed inputted by the operator while a throttle opening is regulated such that a detected engine speed converges to the inputted desired engine speed, a fuel injection amount prepared for mixed fuel is increased/decreased when a load is kept constant and the output air/fuel ratio (at which an output of the engine becomes maximum) is estimated. A rate of alcohol contained in the fuel is estimated from the estimated air/fuel ratio and the fuel injection amount is corrected based on the estimated alcohol rate, thereby determining the fuel injection amount appropriately in accordance with the estimated alcohol rate.

Abstract: In an apparatus for discriminating a piston stroke of a general-purpose internal combustion engine connectable to an operating machine to be used as a prime mover of the machine and having a four-stroke operating cycle comprising intake, compression, expansion and exhaust, the operating cycle is discriminated based on intake air temperature detected by an intake air temperature sensor whether a stroke next to a predetermined crank angular position at which a crank angle sensor produces an output is the intake stroke or the expansion stroke, when operation of the engine is determined to be under a stable condition. With this, it becomes possible to discriminate the four-stroke operating cycle of the general-purpose engine without using an expensive pressure sensor.

Abstract: A power generator starts an engine by overcoming an inrush current occurs. A calculator (21) retrieves an outputtable current of a generator according to an engine speed. A calculator (23) calculates the lacking amount of the outputtable current relative to a load current. When the remaining battery level is sufficient, a DC/DC converter controller (24) supplies a current corresponding to the lacking amount from the battery (4) to a DC part (52). If the battery (4) starts supplying a power, FETs (Qa to Qf) of a rectifying part (51) are powered off and an output of the power generator (3) is stopped. When an engine frequency stability deciding part (27) decides the engine frequency is stable the rectifying part (51) restarts the output of the generator (3) and the current supply from the battery (4) to the DC part (52) is stopped.

Abstract: In an apparatus for controlling warm-up operation of a general-purpose internal combustion engine having a throttle valve installed in an air intake pipe and connectable to an operating machine to be used as a prime mover of the machine, it is configured to calculate a basic fuel injection amount based on an engine speed and a throttle opening and control engine warm-up operation by calculating a warm-up time fuel injection amount by correcting the calculated basic fuel injection amount based on one of a temperature change amount of a spark plug seat of the engine, the throttle opening and an output of the operating machine and injecting fuel from an injector by the calculated warm-up time fuel injection amount. With this, it becomes possible to calculate a fuel injection amount suitable for the engine warm-up condition by using an appropriate parameter in place of the lubricating oil temperature.

Abstract: In an apparatus for detecting fuel shortage of a general-purpose internal combustion engine connectable to an operating machine to be used as a prime mover of the machine, the engine being supplied with fuel stored in a tank and having an actuator adapted to open and close a throttle valve installed in an air intake pipe so as to achieve a desired engine speed set by an operator, comprising a fuel shortage condition detector adapted to detect whether the engine is in a fuel shortage condition, and an engine stopper adapted to stop the engine when the engine is detected to be in the fuel shortage condition. With this, it becomes possible to detect whether the engine having the electronic governor is in the fuel shortage condition, thereby preventing occurrence of trouble such as afterburning.

Abstract: In an apparatus for discriminating a piston stroke of a general-purpose internal combustion engine connectable to an operating machine to be used as a prime mover of the machine and having a four-stroke operating cycle comprising intake, compression, expansion and exhaust, the operating cycle is discriminated based on intake air temperature detected by an intake air temperature sensor whether a stroke next to a predetermined crank angular position at which a crank angle sensor produces an output is the intake stroke or the expansion stroke, when operation of the engine is determined to be under a stable condition. With this, it becomes possible to discriminate the four-stroke operating cycle of the general-purpose engine without using an expensive pressure sensor.

Abstract: A power generator starts an engine by overcoming an inrush current occurs. A calculator (21) retrieves an outputtable current of a generator according to an engine speed. A calculator (23) calculates the lacking amount of the outputtable current relative to a load current. When the remaining battery level is sufficient, a DC/DC converter controller (24) supplies a current corresponding to the lacking amount from the battery (4) to a DC part (52). If the battery (4) starts supplying a power, FETs (Qa to Qf) of a rectifying part (51) are powered off and an output of the power generator (3) is stopped. When an engine frequency stability deciding part (27) decides the engine frequency is stable the rectifying part (51) restarts the output of the generator (3) and the current supply from the battery (4) to the DC part (52) is stopped.

Abstract: Suppresses noise due to high engine speed and improves emission and fuel consumption of a hybrid generator. A difference computing unit 29 computes a first difference between an alternator output and a load output. A difference computing unit 31 computes a second difference between a battery output and the load output. When the battery output is greater than a battery output stopping threshold, the alternator output is fixed and the first difference is compensated for by the battery output. When the battery output is less than the battery output stopping threshold, the engine speed is increased to compensate for the second difference by the output of the alternator 3. To compensate for the second difference, a target engine speed is determined using a relationship of the second difference and the target engine speed. The engine speed is converged at the target engine speed.

Abstract: A PLL circuit is disclosed that comprises a controlling unit that switches at a predetermined timing to enable/disable the phase difference signal supplied from the phase comparator to the low pass filter; and a resistor element that is disposed between a predetermined potential and a signal line for supplying the phase difference signal from the phase comparator to the low pass filter, when the phase difference signal is enabled, the oscillation circuit performing oscillation operation based on the voltage signal corresponding to the phase difference signal, when the phase difference signal is disabled, the low pass filter being supplied with the predetermined potential through the resistor element to allow the oscillation circuit to perform oscillation operation based on the voltage signal generated depending on the supplied predetermined potential.

Abstract: In an apparatus for controlling an air/fuel ratio of a general-purpose internal combustion engine using mixed fuel containing alcohol and gasoline and operated at a desired engine speed inputted by the operator while a throttle opening is regulated such that a detected engine speed converges to the inputted desired engine speed, a fuel injection amount for mixed fuel determined based on fuel injection amount characteristics is increased/decreased when a load is kept constant and the output air/fuel ratio (at which an output of the engine becomes maximum) is estimated. And the fuel injection amount is corrected based on the estimated air/fuel ratio, thereby enabling to estimate the output air/fuel ratio without using an expensive air/fuel ratio sensor and to feedback-control the fuel injection amount such that the engine is operated at the output air/fuel ratio.

Abstract: In an apparatus for controlling an air/fuel ratio of a general-purpose internal combustion engine using mixed fuel containing alcohol and gasoline and operated at a desired engine speed inputted by the operator while a throttle opening is regulated such that a detected engine speed converges to the inputted desired engine speed, a fuel injection amount prepared for mixed fuel is increased/decreased when a load is kept constant and the output air/fuel ratio (at which an output of the engine becomes maximum) is estimated. A rate of alcohol contained in the fuel is estimated from the estimated air/fuel ratio and the fuel injection amount is corrected based on the estimated alcohol rate, thereby determining the fuel injection amount appropriately in accordance with the estimated alcohol rate.

Abstract: In an apparatus for controlling an air/fuel ratio of a general-purpose internal combustion engine using mixed fuel containing alcohol and gasoline and operated at a desired engine speed inputted by the operator while a throttle opening is regulated such that a detected engine speed converges to the inputted desired engine speed, a fuel injection amount determined for mixed fuel based on fuel injection amount characteristics is increased/decreased when a load is kept constant and the output air/fuel ratio is estimated to correct the fuel injection amount by the estimated air/fuel ratio, while a switch (knob) is installed to be manipulated by the operator to switch the fuel injection amount characteristics.

Abstract: A fuel injection control system corrects the amount of fuel injected by fuel injection valves toward an increased side when an acceleration state resulting from operation of a throttle occurs. A control unit includes a detector, an acceleration state determinor, and an acceleration corrector. When an increase in the detected value is a predetermined value or more within a first predetermined time period, the acceleration state determiner determines that a state is an acceleration state and inputs a signal inducing fuel-amount-increase correction to the acceleration corrector. When the state where an amount of change in the detected value reaches a predetermined value or more in an increasing or decreasing direction within a first predetermined time period continuously occurs a predetermined number of times or more before a second predetermined time period expires, determination of the acceleration state is stopped until a third predetermined time period passes.

Abstract: A fuel injection control system corrects the amount of fuel injected by fuel injection valves toward an increased side when an acceleration state resulting from operation of a throttle occurs. A control unit includes a detector, an acceleration state determinor, and an acceleration corrector. When an increase in the detected value is a predetermined value or more within a first predetermined time period, the acceleration state determiner determines that a state is an acceleration state and inputs a signal inducing fuel-amount-increase correction to the acceleration corrector. When the state where an amount of change in the detected value reaches a predetermined value or more in an increasing or decreasing direction within a first predetermined time period continuously occurs a predetermined number of times or more before a second predetermined time period expires, determination of the acceleration state is stopped until a third predetermined time period passes.

Abstract: A PLL circuit is disclosed that comprises a controlling unit that switches at a predetermined timing to enable/disable the phase difference signal supplied from the phase comparator to the low pass filter; and a resistor element that is disposed between a predetermined potential and a signal line for supplying the phase difference signal from the phase comparator to the low pass filter, when the phase difference signal is enabled, the oscillation circuit performing oscillation operation based on the voltage signal corresponding to the phase difference signal, when the phase difference signal is disabled, the low pass filter being supplied with the predetermined potential through the resistor element to allow the oscillation circuit to perform oscillation operation based on the voltage signal generated depending on the supplied predetermined potential.

Abstract: A lock detecting circuit is disclosed that detects whether a PLL circuit is in a locked state based on a phase difference signal supplied from a phase comparator of the PLL circuit, the lock detecting circuit comprising a first circuit that outputs a control signal having one level when the phase difference signal does not indicate a generation of a phase difference, and the other level when the phase difference signal indicates a generation of a phase difference; a second circuit that latches the control signal; and a third circuit that outputs, for a predetermined second term, a lock detecting signal indicating that the PLL circuit is in a locked state, when the latched control signal indicates the one level for a predetermined first term.

Abstract: A printer includes an instruction book specification unit that accepts a specification of an instruction book in which print instructions are described; a document specification unit that accepts a specification of a document to be printed; and a print processing unit that prints the specified document in accordance with the print instructions described in the specified instruction book.

Abstract: A printing system has an information processing apparatus and a printing apparatus, wherein the information processing apparatus includes: an extraction section that extracts a cross reference table and a trailer from a PDF file to be printed; and a transmission section that first transmits the extracted cross reference table and the trailer to the printing apparatus, and then transmits a body of the PDF file, and wherein the printing apparatus includes: a reception section that receives the cross reference table and the trailer from the information processing apparatus and then receives the body; and a print processing section that starts print processing of the PDF file without waiting for completion of receipt of the body, by using the received cross reference table and the trailer.

Abstract: A printer includes a print request acceptance unit that accepts a print request that includes an instruction book in which print instructions are described; an instruction book determination unit that determines if the print instructions described in the accepted instruction book can be executed on the printer; an instruction book correction unit that, when it is determined that the print instructions described in the instruction book cannot be executed, corrects the instruction book and generates an instruction book in which print instructions executable by the printer are described; and an instruction book output unit that outputs the generated instruction book.