Engine kill-switch control circuit and method of operating the same
AssigneeWalbro Engine Management, L.L.C.
InventorsMartin N. Andersson, George M. Pattullo
Life of this patent
Estimating the term…
Abstract
A kill-switch control circuit for use with a light-duty combustion engine determines whether to execute a controlled shut down method or an immediate shut down method in response to kill-switch activation. The selection of a shut down method is made, at least in part, by using engine speed readings and by counting engine revolutions. The controlled shut down method utilizes ignition timing delay and/or spark ratio techniques to quickly bring the engine to a stop, yet does so in a controlled manner that avoids backfiring and other undesirable effects. Conversely, the immediate shut down method abruptly stops sending a current to the spark plug.
Claims20
A control circuit for use with a combustion engine, comprising:
- a kill-switch having an output that provides a shut down signal;
- and
- an electronic processor having an input that receives said shut down signal and an output that provides a trigger signal;
- wherein upon receiving said shut down signal, said electronic processing device provides at least a first trigger signal at a first ignition timing and a second trigger signal at a second ignition timing that is delayed relative to said first ignition timing.
An ignition system having:
- an input winding for inducing a voltage;
- an ignition timing circuit for storing said induced voltage in the form a stored charge;
- and
- a primary winding for transforming said stored charge into a high voltage ignition pulse;
- wherein said ignition timing circuit at least includes a control circuit, comprising:
- a kill-switch having an output that provides a shut down signal;
- and
- an electronic processor having an input that receives said shut down signal and an output that provides a trigger signal;
- wherein upon receiving said shut down signal, said electronic processing device provides at least a first trigger signal at a first ignition timing and a second trigger signal at a second ignition timing that is delayed relative to said first ignition timing.
A control circuit for use with a combustion engine, comprising:
- a kill-switch having an output that provides a shut down signal;
- and
- an electronic processor having an input that receives said shut down signal and an output that provides a trigger signal;
- wherein upon receiving said shut down signal, said electronic processor provides at least a first trigger signal according to a first ratio of sparks to engine revolutions (sparks:revolutions) and a second trigger signal according to a second ratio of sparks to engine revolutions (sparks:revolutions), wherein each of said first and second ratios is less than 1.
An ignition system having:
- an input winding for inducing a voltage;
- an ignition timing circuit for storing said induced voltage in the form a stored charge;
- and
- a primary winding for transforming said stored charge into a high voltage ignition pulse;
- wherein said ignition timing circuit at least including a control circuit, comprising:
- a kill-switch having an output that provides a shut down signal;
- and
- an electronic processor having an input that receives said shut down signal and an output that provides a trigger signal;
- wherein upon receiving said shut down signal, said electronic processor provides at least a first trigger signal according to a first ratio of sparks to engine revolutions (sparks:revolutions) and a second trigger signal according to a second ratio of sparks to engine revolutions (sparks:revolutions), wherein each of said first and second ratios is less than 1.
A shut down method for use with a light-duty combustion engine, comprising the steps of:
- (a) generating a shut down signal in response to activating a kill-switch;
- (b) determining an ignition timing delay for facilitating a controlled shut down of the engine;
- and
- (c) providing a plurality of high voltage ignition pulses having a progressive ignition timing delay to a spark plug in response to receiving said shut down signal, such that the ignition timing of each trigger signal is delayed relative to the ignition timing of the preceding trigger signal.
Dependencies are inferred from the claim text.