Faoi ghníomh an ardvoltais, déanfaidh an t -aer idir an leictreoid lárnach agus an taobh -leictreoid den phlocóid spréach ianú go tapa, ag cruthú ian atá luchtaithe go dearfach agus ag muirearú leictreoidí saor in aisce . Nuair a shroicheann an voltas idir na leictreoidí luach áirithe, líon na n -ian agus na leictreoin i méaduithe gás cosúil le hairiú, is féidir leis an gás a mhéadaíonn an t -ainse, an t -ionraidh a dhíríonn an t -ionraidh a dhíríonn an t -asann a dua a dhíríonn an t -asann a dua a dhruideann an t -asann an t -dua. causing the "breakdown" phenomenon to occur. At this time, the gas forms a light-emitting body, that is, "spark". As it expands under heat, a "pop" sound also occurs. The temperature of this electric spark can be as high as 2000-3000℃, which is enough to ignite the mixture in the combustion Seomra an tsorcóra .
