SAE J139:2020 pdf free

SAE J139:2020 pdf free.lgnition System Nomenclature and Terminology
A dual coil per cylinder ignition system that operates in an alternating charge/discharge mode with the two coil outputs summed together to fire a single spark plug. The first coil fires the spark plug initially and then the coils alternate between charging and discharging (out of phase with one another) to support a continuous discharge for as long as the ECU continues to cycle the coils.
A single coil ignition system whereby a DC supply is used to“boost” the charge state of the primary coil between secondary discharge events, thereby supporting a continuous secondary discharge for as long as the ECU continues to cycle the coil. The DC supply voltage must be sufficiently high for the coil to act as a step-up transformer, as in a capacitive discharge system.
A system in which both ends of a secondary winding of a high voltage transformer are connected to a spark plug each on opposing cylinders, allowing the use of one coil for every two cylinders on the engine. The coil is energized once per engine revolution, firing both spark plugs at the subsequent demand voltage for each, one on the compression stroke and one on the exhaust stroke. The compression stroke firing is intended to ignite the air/fuel mixture, while the opposing exhaust stroke firing is“wasted” as no ignitable mixture should be present.
An ignition concept whereby high voltage pulses (typically nanosecond pulses) are delivered to an electrode gap at high frequency, short of the required spark voltage, whereby streamers sufficient to ignite an air/fuel mixture by dissociation are formed in the gap.
An ignition system whereby high frequency (typically RF frequency) AC voltage is delivered to a single electrode of an igniter plug with no specific ground electrode. Installed inside the combustion chamber, the ignition system ground is created by the combustion chamber wall surfaces. The applied voltage to the igniter plug is lower than required to produce an arc discharge to the ground, whereby producing high voltage plasma streamer(s) (one or more) sufficient to ignite the air/fuel mixture, that extend outward from the electrode tip (tips) into the combustion chamber. The resulting ignition event is characteristically multiple cycles of high voltage AC plasma with very low current (cold plasma).SAE J139 pdf free download.