What to expect ?

[Externet]

Hi.
What to expect at the secondary winding terminals of a plain spark plug high voltage coil if the primary is fed with sinusoidal 12VAC ? From HV terminal to common chassis, will it arc spark 5mm ? 10mm? 15mm ? nothing ?

This is an image from a triple coil double-terminals, perhaps for automotive "V6 lost spark mode" Consider only a single. (Picture borrowed from the web)

 

[alec_t]

A Kettering-type coil with a typical turns ratio of 100:1 is only going to give an output voltage of 12 x 100 = 1200V at modest sinusoidal AC frequencies, so a very small arc if any.

 

[crutschow]

A Kettering-type coil with a typical turns ratio of 100:1 is only going to give an output voltage of 12 x 100 = 1200V at modest sinusoidal AC frequencies, so a very small arc if any.

At that is only if the core doesn't saturate at the frequency of the 12Vac.

 

[Externet]

Thanks. Oooops... forgot to state the frequency... Yes, plain 60 Hz. Would it take square wave or pulses for the spark to really jump over 10mm ?