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).

A method for safely capturing an engine RPM threshold in a spark-ignition internal combustion engines which may exceed the maximum safe unloaded RPM for that engine. Typical engines having a safe RPM high speed redline when coupled to a load, and a reduced RPM redline when decoupled and unloaded, can be set to activate ancillary equipment at a high redline, engine loaded RPM by deriving and processing data from the engine at a low, unloaded reduced RPM speed. The method requires operator reference to an existing OEM or after-market tachometer which enables the user to set a low RPM reference point while the engine is unloaded and running at a slow RPM. Raw data from the latter variable RPM threshold selected by a user is safely captured while the engine is operating unloaded, and a higher RPM threshold is calculated and set from the raw data. The higher RPM threshold may exceed the maximum safe unloaded RPM for said engine.

A method for safely capturing an engine RPM threshold in a spark-ignition internal combustion engines which may exceed the maximum safe unloaded RPM for that engine. Typical engines having a safe RPM high speed redline when coupled to a load, and a reduced RPM redline when decoupled and unloaded, can be set to activate ancillary equipment at a high redline, engine loaded RPM by deriving and processing data from the engine at a low, unloaded reduced RPM speed. The method requires operator reference to an existing OEM or after-market tachometer which enables the user to set a low RPM reference point while the engine is unloaded and running at a slow RPM. Raw data from the latter variable RPM threshold selected by a user is safely captured while the engine is operating unloaded, and a higher RPM threshold is calculated and set from the raw data. The higher RPM threshold may exceed the maximum safe unloaded RPM for said engine.

An internal-combustion-engine combustion state detecting apparatus is configured in such a way as to include a circulation unit that short-circuits a primary winding so as to form a circulation path including the primary winding, while a spark discharge is produced in an ignition plug, and a circulation current control unit that controls a circulation current flowing in the circulation path and in such a way that based on an ion current detected by an ion current detection apparatus, the combustion state of an inflammable fuel-air mixture is detected.

Methods and systems are provided for an internal combustion engine having at least one combustion chamber for burning a fuel mixture and a spark plug for performing spark ignition of the fuel mixture in the combustion chamber. The spark plug includes electrodes for generating an ignition spark at a location within the combustion chamber. Furthermore, the internal combustion engine includes an adjustment device for reducing a distance between the location of the ignition spark and an edge of the combustion chamber in the case of an increase in temperature of the internal combustion engine during operation.

Methods and systems are provided for an internal combustion engine having at least one combustion chamber for burning a fuel mixture and a spark plug for performing spark ignition of the fuel mixture in the combustion chamber. The spark plug includes electrodes for generating an ignition spark at a location within the combustion chamber. Furthermore, the internal combustion engine includes an adjustment device for reducing a distance between the location of the ignition spark and an edge of the combustion chamber in the case of an increase in temperature of the internal combustion engine during operation.

An ignition timing control device has a knocking detection unit and an ignition timing adjustment unit. In a condition that the operation state of the internal combustion engine is suitable for adjustment of the ignition timing, the ignition timing control device outputs to an igniter an adjusted ignition signal as adjusted (corrected) by an adjusted ignition timing determination process. The ignition timing control device outputs to the igniter a reference ignition signal as it is outputted from an internal combustion engine control unit without adjustment (correction) in a condition that the operation state of the internal combustion engine is not suitable for adjustment of the ignition timing.

An ignition timing control device has a knocking detection unit and an ignition timing adjustment unit. In a condition that the operation state of the internal combustion engine is suitable for adjustment of the ignition timing, the ignition timing control device outputs to an igniter an adjusted ignition signal as adjusted (corrected) by an adjusted ignition timing determination process. The ignition timing control device outputs to the igniter a reference ignition signal as it is outputted from an internal combustion engine control unit without adjustment (correction) in a condition that the operation state of the internal combustion engine is not suitable for adjustment of the ignition timing.

An ignition system and a method for suppressing an ignition spark discharge at a spark gap at an unsuitable time are provided. The method includes a recognition of a spark breakaway and/or a failed ignition and, in response thereto, by producing a conductive path via an ignition spark at the spark gap at a suitable time.

An ignition system and a method for suppressing an ignition spark discharge at a spark gap at an unsuitable time are provided. The method includes a recognition of a spark breakaway and/or a failed ignition and, in response thereto, by producing a conductive path via an ignition spark at the spark gap at a suitable time.