A method for controlling a corona ignition system in which a corona discharge is produced at an ignition electrode by exciting a resonating circuit with an AC voltage produced by a high-frequency generator. The AC voltage is adjusted to a target value depending on an operating state of the engine. Combustion onset is determined by evaluating an electrical variable of the resonating circuit and the target value of the AC voltage is reduced by a predefined value following a predefined number of engine cycles or a predefined operating period. The determined combustion onset is evaluated in one or more engine cycles. The target value for the momentary engine operating state is then increased if, by evaluation of the combustion onset, it is found that a predefined requirement is no longer met. Otherwise, the reduced target value is stored as a new target value for the momentary engine operating state.

A control apparatus, which is for an internal combustion engine with a spark plug having a center electrode and a ground electrode disposed so as to form a spark discharge gap therebetween, includes a voltage applying section for applying a voltage to the spark discharge gap, a constant-voltage path including a constant-voltage element parallel-connected to the spark discharge gap of the spark plug for preventing the spark discharge gap from being applied with a voltage higher than a set voltage, and an operation control circuit for controlling an operating condition of the internal combustion engine. The operation control circuit is configured to measure a current-flowing time during which a current flows through the constant-voltage path when a voltage higher than the set voltage is applied to the constant-voltage path, and change the operating condition of the internal combustion engine in accordance with the measured current-flowing time.

An internal combustion engine is described and includes a combustion chamber formed by cooperation of a cylinder bore formed in a cylinder block, a cylinder head and a piston. A plasma ignition controller is electrically connected to a groundless barrier discharge plasma igniter that includes a tip portion disposed to protrude into the combustion chamber. A current sensor is disposed to monitor secondary current flow between the plasma ignition controller and the groundless barrier discharge plasma igniter. The plasma ignition controller is disposed to execute a plasma discharge event. A controller is disposed to monitor a magnitude of the secondary current flow via the current sensor during the plasma discharge event. The controller includes an instruction set executable to evaluate integrity of the groundless barrier discharge plasma igniter based upon the magnitude of the secondary current flow during the plasma discharge event.

An ignition control device includes a control unit to control first to third switching elements so that during ignition discharge, which is started by turning off the first switching element, energy stored on a capacitor is discharged by turning off the third switching element and turning on the second switching element for supplying a primary current to an end of a primary winding opposite to an end thereof connected to a direct-current power supply. During inductive discharge of a spark plug, the control unit non-intermittently turns on the second switching element so that the second switching element is turned on over a successive energy input time period, according to the operating conditions of an internal combustion engine.

The ignition control device includes a spark plug that includes a first electrode and a second electrode disposed so as to oppose each other, an ignition coil that includes a plurality of sets of a primary coil and a secondary coil, generates a high voltage in the secondary coil by energizing or interrupting a primary current supplied to the primary coil, and applies the generated high voltage to the first electrode, and a control unit that, in a case where a plurality of the primary coils are driven during a single ignition process, temporarily stops energization of a primary current supplied to a second primary coil when a primary current supplied to a first primary coil is interrupted, and re-energizes the primary current supplied to the second primary coil following the elapse of an energization stoppage period.

A battery power management apparatus, including a first battery capable of providing electrical power to a first load of a vehicle at a selected time, wherein the first load does not draw current when an ignition system is not operating; a second battery capable of providing electrical power to a second load which draws current when the ignition system is not operating; a first switch capable of disconnecting the first battery from a first circuit containing the ignition system; a second switch capable of connecting the first battery to the first circuit containing the ignition system and is capable of connecting the first battery to a second circuit containing the first load; and an alternator which recharges both the first battery and second battery simultaneously when the ignition system is operating. The second battery provides electrical power to the second load when the alternator ceases to operate.

A fuel property determination apparatus for an internal combustion engine is applied to an internal combustion engine that is equipped with an ignition plug and an ignition timing controller. An electronic control unit provided in the fuel property determination apparatus executes a determination process of making a determination on a property of a fuel supplied to the internal combustion engine based on an ignition sufficiency ratio, during a predetermined period after startup of the internal combustion engine. The electronic control unit is configured to determine that the property of the fuel is heavy when a determination index value that is obtained by subjecting the ignition sufficiency ratio to a smoothing process is equal to or larger than a predetermined threshold. The electronic control unit is configured to set a smoothing coefficient to a value corresponding to each of a first period, a second period, and a third period.

An ignition system includes: a step-up transformer having a primary side and a secondary side; an electric energy source which is able to be connected to the primary side; a spark gap, which is designed to carry a current transferred to the secondary side by the step-up transformer. The step-up transformer has a bypass for transferring electric energy from the electric energy source to the secondary side. The bypass is designed to support a decaying electrical signal in the secondary coil of the high-voltage generator as of a predefined time, or as of a predefined intensity of the current being reached.

A method for checking electrodes of a spark gap of an ignition system for a combustion chamber of an internal combustion engine with an externally provided ignition includes generating a spark at the spark gap in an operating state without ignition of an ignitable mixture in the combustion chamber; ascertaining a parameter or characteristic function representing the spark current, the spark voltage, and/or the spark duration; comparing the parameter or the characteristic function to a reference; adapting an energy for a voltage buildup for a further spark generation for the mixture ignition and/or for maintaining an ignition spark for the mixture ignition, in particular for a future ignition process, as a function of a difference between the parameter or the characteristic function and the reference.

An ignition system for an internal combustion engine has a power source, a transformer having first and second primary windings and a secondary winding, a connector extending from the secondary winding and adapted so as to connect with a terminal of the spark plug of the internal combustion engine, and electronic spark timing circuit cooperative with the transformer so as to activate and deactivate voltage to the first and second primary windings. The first and second primary windings are connected to the power source such that the transformer produces an alternating voltage output from the secondary winding of between 1 kHz and 100 kHz and a voltage of at least 20 kV. A forced push-pull inverter is cooperative with the electronic spark timing circuit so as to fix a frequency of voltage to the first and second primary windings.