# Re: Racing Spark Prediction

```Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi Paul,

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In thinking about the primary induction and secondary self induction that you mention, Im wondering if there is a third component to the voltage profile.
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Say the primary fires and the primary induction creates a voltage profile on the secondary. Any voltage gradient from say one turn to the next will start a traveling wave following the wire path. The current from this traveling wave will result in self induction of the secondary.
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1. Primary induction happens almost instantaneously across the entire coil. Magnetic field travels at speed of light from primary to a particular turn on the coil and in general the arrival of the field will be a little different from one turn to another.
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2. The traveling wave follows the wire path (one component to the total poynting vector) and time taken to reach the top of the coil is the time taken to propagate the wire path. For a 1000 turn coil probably 1000 little traveling waves each starting from a different turn of the coil if you get my meaning here. Maybe take the primary induction profile as initial conditions on the wire path and start propagating a forward and reverse wave (I got to think more about this).
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3.The current flowing by the traveling waves creates a magnetic field that propagates at the speed of light to all other turns in a direct path instead of following the wire path.
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The total voltage at any given instant would then seem to be the sum of all three effects. Does this paradigm seem reasonable???
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Gerry R.

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```> Original poster: Paul Nicholson <paul@xxxxxxxxxxxxxxxxxxx>

>  > [racing arcs]

> I posted a list of some possible causes, a while ago now,
>   http://www.pupman.com/listarchives/2002/July/msg00429.html

> At any instant, the secondary voltage distribution is the sum
> of the primary induction and the secondary self induction
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