Abstract: A lawn care device may include an engine to selectively power the lawn care device, a frame supporting the engine of the lawn care device, an ignition system for selectively powering the lawn care device based at least in part on operation of an ignition interface controlled by a processor (310), an optical isolator (320) which detect the operational presence of the processor (310) and a shutdown circuit (300) which is able to ground out the ignition coil (360) as a function of the conductive state of the optical isolator (320); the shutdown circuit being powered by an ignition coil (360) of the ignition system to generate a failsafe condition in response to failure or loss of the processor (310).

Abstract: When throttle lever is pulled with the rotation lock member of the engine-powered tool in a state in which rotation of rear handle is permitted, the electrode terminal provided on the rotation lock member and the electrode terminal provided on throttle lever contact each other. As a result of this contact, the two output terminals of the engine generator are short-circuited, the supply of electric power to the ignition device from the engine generator is stopped and the supply of electric power from the ignition device to sparkplug in the engine is stopped. Through this, operation of the blade is prevented when rotating rear handle.

Abstract: The invention relates to a portable hand-guided work apparatus having an internal combustion engine (10) for driving a work tool (5). A combustion chamber (12) is formed in a cylinder (11) of the engine (10) and is delimited by a piston (13) which drives a crankshaft (14) in rotation. A spark plug (16) is held in the cylinder (11) and is driven by an ignition module (20) to ignite a compressed air/fuel mixture in the combustion chamber (12) to drive the piston (13). A short circuit line (21) is provided on the ignition module (20) for switching off the ignition. The short circuit line (21) is configured as a bus line (30) in order to make available, in a simple manner, a plurality of further operating parameters to the ignition module. An external control apparatus (23, 24) and/or sensors (25, 26) are connected to the bus line (30).

Abstract: An automotive ignition system includes a control circuit (52) operable to drive a coil current switching device (24) connected to an ignition coil (30) referenced at battery voltage. The control circuit (52) includes a drive circuit (20) and ring damping circuit (58) producing an inhibit signal (INH) to which the drive circuit (20) is responsive to control the state of the coil drive signal (GD). In a single pulse ignition system; i.e., an ignition system employing a single coil charging event per combustion cycle, the ring damping circuit (58) is responsive to a spark control signal (ESTBF) to control charging and discharging of a single capacitor (C1) to define the inhibit signal (INH). In a multiple pulse ignition system; i.e.

Abstract: An electronic ignition system replacing corresponding stock circuitry but utilizing the stock magneto and ignition coil provided with the engine of a sport vehicle, such as a jet ski or snowmobile, to provide improved performance. A timing circuit is provided as part of the ignition circuitry to enable a trigger pulse of a predetermined duration to be delivered to the ignition coil and further, to inhibit subsequent trigger pulses limiting the engine speed below a determined rpm limit. The timing circuitry uses an over-temperature switch connecting a capacitance to lengthen the inhibit time period reducing the maximum rpm limit. A holeshot switch connected across the over-temperature switch lowers the rpm limit while the throttle is held in the full speed position. Compensated pickup circuitry, automatic battery connect/disconnect, low impedance kill switch circuitry and an impedance protected tachometer output is provided to enhance the performance and features of the ignition systems of sport vehicles.

Abstract: During an abnormal stop condition of an internal combustion engine, the semiconductor devices which control the supply of current to the ignition coils during a dwell time are subject to damage by a high transient current. To prevent this, at least one predetermined time interval is selected on the basis of detected engine temperatures and/or battery supply voltage level and this selected time interval is compared to a time period between reference pulses from a crank angle sensor. When the time period between reference pulses exceeds the selected time interval, a stop condition of the engine is indicated and the semiconductor devices which supply ignition current are controlled to shorten the dwell time or entirely stop the supply of current to the ignition coils.

Abstract: An automatic power interrupting system for a vehicular control circuit including a relay switch having a contact connected between a power source and the supply terminal of a control circuit and a relay coil connected with the power source, a control switch connected between the power source and the supply terminal and with the signal input terminal of the control circuit and turned on only by an external force, a revolution detector for detecting engine revolutions and a switching device for turning the relay switch on when power is supplied to the circuit and off after a predetermined time period measured after stop of the engine based on a signal from the revolution detector.

Abstract: A snowmobile electrical system having a battery conservation circuit. The system is designed to conserve battery power after deactivation of the engine using the kill switch, even if the key switch is left on. Battery power is normally consumed by continued connection of the microprocessor-based electronic engine control unit (ECU) to the battery after kill switch activation. To prevent battery consumption, the ECU monitors the electrical output of the ignition system at a position within the system wherein the output is dependent on engine speed. If the output drops to a specified level, a signal generator in the ECU is activated. Signals from the signal generator are directed to a solid state switching system which disconnects the battery from the ECU. As a result, battery consumption is controlled.

Abstract: An ignition device includes a capacitor 119, a semiconductor switch element 104 and an ignition control circuit 101, by which the cut-off of current supply to the ignition coil 105 is made gradual by supplying charge of the capacitor to the semiconductor switching element when the engine is stopped or the stop switch 117 is operated, the problems caused by undesired abrupt cut-off of the ignition current are eliminated.

Abstract: An ignition control device for an internal combustion engine includes a digital control circuit which functions to reduce gradually a current flowing through a primary side of an ignition coil when a current supply to the primary side of the ignition coil continues for a time longer than a normal current supply period, to thereby prevent undesired spark discharge from occurring in an ignition plug.

Abstract: An ignition timing control system for an internal combustion engine cuts the ignition when the engine rotational speed is below a threshhold speed indicative of stall. On starting, the threshhold speed is set low. The engine speed is monitored, and a higher threshhold is set when the engine has attained a speed indicative of full combustion.

Abstract: The present invention is an ignition device comprising a circuit for generating an ignition signal in synchronism with the revolutions of an engine, a circuit for inhibiting an igniting operation, a circuit for detecting the starting state of the engine, and a circuit for interrupting the operation of the inhibiting circuit upon detection of such starting state.

Abstract: A method and apparatus for measuring of concentrations of components of a fluid mixture. One side of a membrane permeable to the component to be determined is contacted with a sample of the fluid mixture to be analyzed. The second side of the membrane is contacted with a test fluid passing the membrane at different speeds. The resultant properties of the test fluid are determined for the different speeds of flow past the membrane and the measured values allow to determine the concentration or partial pressure of the component in the fluid mixture. The fluid mixture is preferably blood and the components can be oxygen and carbon dioxide. Preferably the membrane provides a spiral path for the test fluid in order to allow employing a more rapid flow of the test fluid past the membrane. Furthermore, such a configuration can be combined with a catheter for hemodynamic blood pressure measurement thereby providing a single probe for continuous monitoring of blood in clinical practice.

Abstract: A spark control apparatus (1) for an internal combustion engine using a breaker point (3) or solid state (5) ignition to control current to an ignition coil (11). The waveform of the ignition signal from the ignition system is applied to a converter section (35) of the apparatus to convert the signal waveform to a predetermined waveform. A sensor (25) senses engine vibration and generates a representative electrical signal which a signal processor (41) processes to determine engine knock by comparing the peak and average values of the signal. A delay circuit (45) delays termination of current to the ignition coil and thus the ignition timing as a function of the comparison of the peak and average values of the control signal. When there is no knock, the timing slowly returns to normal. A driver (50) responds to current signals to control current to the ignition coil. The driver is shut off when the engine is not running to reduce current drain.

Abstract: An ignition coil energizing circuit is provided which has a signal generator for generating an output signal having a frequency corresponding to an engine rotational speed, a switching circuit connected to an ignition coil, a current detector for detecting a current flowing through the ignition coil, a duty control for supplying to the switching circuit a control signal having a duty cycle corresponding to a duty cycle of an output signal from the signal generator and controlling a conduction state of the switching circuit, and a current control circuit for controlling the switching circuit in response to an output signal generated from the current detector and maintaining a current flowing through the current detector at a predetermined value.

Abstract: An electronic ignition system having an automatic shutdown feature is disclosed. In a first embodiment of the invention, should an output terminal of an integrated circuit (10, 10a) remain in a high voltage condition for a prolonged period of time, a capacitor (C100) which is charged from a constant voltage and alternately discharged through a terminal (105) of the integrated circuit, is allowed to charge, and gradually reaches the threshold voltage of a transistor (Q200) which is connected to shunting transistor (Q1), which diverts current from transistor (Q2) in series with an ignition coil primary winding (76, 76a) and gradually deenergizes the ignition system. In a second embodiment, a capacitor (C200) is charged from a constant voltage, and alternately discharged by being shorted by an inverting transistor (Q300) connected to a terminal (205) of an integrated circuit (200, 200a), which provides a signal which is the compliment of an output terminal.

Abstract: A stall circuit is described for use in combination with an electronic adaptive dwell ignition system which allows an ignition coil to be de-energized whenever the frequency of operation of the ignition system decreases below a specified frequency without causing a spark to be generated in the engine of an automobile controlled by the ignition system while allowing continued operation of the ignition system to generate a spark in response to a spark command being generated with minimum spark retard.

Abstract: In an internal combustion engine in which the fuel supply is interrupted during no-load operation to save gas the ignition timing is retarded following resumption of the fuel supply to cause the resumed torque to be applied slowly. A sequence of ignition timing signals following the activation of the gas pedal is delayed by sequentially smaller and smaller amounts until the normal ignition timing is resumed.

Abstract: A snowmobile electrical system having a battery conservation circuit. The system is designed to conserve battery power after deactivation of the engine using the kill switch, even if the key switch is left on. Battery power is normally consumed by continued connection of the microprocessor-based electronic engine control unit (ECU) to the battery after kill switch activation. To prevent battery consumption, the ECU monitors the electrical output of the ignition system at a position within the system wherein the output is dependent on engine speed. If the output drops to a specified level, a signal generator in the ECU is activated. Signals from the signal generator are directed to a solid state switching system which disconnects the battery from the ECU. As a result, battery consumption is controlled.