DaveEFI wrote:Very basically a spark gap before it fires has a very high impedance in relation to the plug lead one. With two resistors in series, if one is very large and one small, you can ignore the smaller one for all practical purposes.
When the breakdown voltage of the spark gap is applied and a spark occurs, the impedance of the gap becomes very much lower due to ionisation of the gas between the points.
Do a Google on spark gap for lots of further information.
Still don't get it. Until the pd reaches the point where it can 'jump' the spark plug gap, no real current is flowing and so the resistance of the leads would have no effect, I understand that. But when the pd reaches high enough to break down the gap and make the spark, a current is flowing (and in some race cars a very high current) so the resistance of the leads would now have an effect on the current flow.
I always understood for max spark you needed copper core leads, but then to use them on the road you needed supressed caps (old) or the newer supressed leads. Not really for limiting the current, but for shaping the waveform, making it a little more rounded, and so eliminating harmonics of the relatively low frequency ignition being produced that could extend into the rf band and so cause interference.
Or am I way off beam here?
