A maximum value of a discharge current from a capacitor 13, detected by a primary-side current detection means 24 disposed at a grounded end of the capacitor 13, is controlled such as not to exceed a predetermined first control value Y1. The first control value Y1 is derived based on magnetic saturation of a primary winding 3, with the control being performed by controlling the on-off state of an energy injection switching means 20. As a result, magnetic saturation of the primary winding 3 can be prevented, and the reliability of an ignition apparatus which incorporates an energy injection circuit 6 can be increased.

The ignition system (10) of an engine (particularly for a UAV) has a primary (10a), and a secondary (10b) ignition system to provide redundancy for get you home capability should the primary ignition system fail. The secondary ignition provides a lower energy or shorter duration spark than the higher energy or longer duration sparking of the primary ignition system, and is retarded relative to primary sparking. Timing of the secondary sparking can be advanced in the event of primary sparking failure. Fuelling strategy can be shifted from a leaner stratified charge to a richer homogenous charge when relying just on the secondary ignition system for ignition. The secondary ignition system can be of a lower spark energy and/or duration than the primary ignition system, avoiding the cost, complexity and weight of replicating the primary ignition system, and to improve packaging within the engine housing, particularly within the limited payload and space limits of a UAV.

An apparatus and a method for a circuit can include a voltage divider having a first and a second impedance in series, and having a voltage divider output. A switchable element is arranged in parallel with the first impedance and connected with the voltage divider output. The switchable element has an open state and a closed state. A spark gap device is configured to not generate a spark when the switchable element is in the open state and generate a spark when the switchable element is in the closed state.

An ignition circuit and a method of operating an igniter (preferably a traveling spark igniter) in an internal combustion engine, including a high pressure engine. A high voltage is applied to electrodes of the igniter, sufficient to cause breakdown to occur between the electrodes, resulting in a high current electrical discharge in the igniter, over a surface of an isolator between the electrodes, and formation of a plasma kernel in a fuel-air mixture adjacent said surface. Following breakdown, a sequence of one or more lower voltage and lower current pulses is applied to said electrodes, with a low simmer current being sustained through the plasma between pulses, preventing total plasma recombination and allowing the plasma kernel to move toward a free end of the electrodes with each pulse.

An ignition circuit and a method of operating an igniter (preferably a traveling spark igniter) in an internal combustion engine, including a high pressure engine. A high voltage is applied to electrodes of the igniter, sufficient to cause breakdown to occur between the electrodes, resulting in a high current electrical discharge in the igniter, over a surface of an isolator between the electrodes, and formation of a plasma kernel in a fuel-air mixture adjacent said surface. Following breakdown, a sequence of one or more lower voltage and lower current pulses is applied to said electrodes, with a low simmer current being sustained through the plasma between pulses, preventing total plasma recombination and allowing the plasma kernel to move toward a free end of the electrodes with each pulse.

An ignition system for a light-duty combustion engine includes a charge winding, a microcontroller and a power supply sub-circuit. The sub-circuit is coupled to both the charge winding and the microcontroller and includes a first power supply switch, a power supply capacitor and a power supply zener. The sub-circuit is arranged to turn off the first power supply switch so that charging of the power supply capacitor stops when the charge on the power supply capacitor exceeds the breakdown voltage on the power supply zener. In at least some implementations, the power supply capacitor may power the microcontroller and the power supply sub-circuit may limit or reduce the amount of electrical energy taken from the induced AC voltage of the charge winding to a level that is still able to sufficiently power the microcontroller yet saves energy for use elsewhere in the system.

A spark ignition engine system for communicating data includes a capacitive discharge ignition system using a microcontroller for controlling the spark ignition of a light-duty internal combustion engine; a memory device communicated with the microcontroller, wherein the micro-controller obtains engine data from the light-duty internal combustion engine and stores the engine data or software using the memory device; and a powering connection and a separate data connection that are electrically connected to different pins of the microcontroller, wherein the powering connection supplies power to the microcontroller while engine data or software is communicated via the data connection.

In at least some implementations, an ignition system for a light-duty combustion engine includes a charge winding, a microcontroller and a power supply sub-circuit. The sub-circuit is coupled to both the charge winding and the microcontroller and includes a first power supply switch, a power supply capacitor and a power supply zener. The sub-circuit is arranged to turn off the first power supply switch so that charging of the power supply capacitor stops when the charge on the power supply capacitor exceeds the breakdown voltage on the power supply zener. In at least some implementations, the power supply capacitor may power the microcontroller and the power supply sub-circuit may limit or reduce the amount of electrical energy taken from the induced AC voltage of the charge winding to a level that is still able to sufficiently power the microcontroller yet saves energy for use elsewhere in the system.

An ignition coil has a core with a longitudinal axis, a secondary winding extending around the core, a sleeve extending around the core, a primary winding wrapped around the sleeve, and a controller connected to the primary winding so as to oscillate alternating current to said primary winding. The secondary winding has a high-voltage end and a low-voltage end. The primary winding is in spaced longitudinal relationship from the secondary winding. Specifically, the primary winding is located longitudinally away from the high-voltage end of the secondary winding. A bobbin is positioned over and around the core. The secondary winding is wrapped around at least a portion of the bobbin.

A solid state spark device that operates as a two terminal spark gap in a CDI exciter of an aircraft ignition system. The device includes a triggering transformer, a triggering circuit, and a control circuit. The triggering circuit is electrically connected to a first coil of the transformer and includes circuit elements connected to supply current to the first coil upon charging of the triggering circuit up to a triggering voltage. This current through the first coil of the triggering transformer induces an output in a second coil of the transformer. The control circuit is electrically connected to the second coil and includes a switch controlled by the output from the second coil. The switch, when activated by the triggering circuit, discharges energy from the exciter into an igniter of the aircraft ignition system.