Wanpela 'automotive relay' em i wanpela 'electromagnetic switch' we i wok long rot bilong wanpela 'electromagnetic mechanism', na i larim ol 'low-signal' long bosim ol 'circuit' we i nidim bikpela 'current'. Ol bikpela samting bilong en em wanpela koil, ol kontek, na wanpela spring, na em i wok bihainim as bilong 'electromagnetic induction'. Taim pawa i ron long koil, wanpela magnetik fil i save kamap, na dispela i save kirapim ol kontek long senis, na dispela i save bosim pawa i ron.
Ol 'automotive relays' i save mekim planti bikpela wok na ol i wanpela bikpela samting bilong wok bilong ol kompleks ilektrikel sistem:
Kontrol bilong Seket: Ol rile i save mekim wok long regulesen bilong seket insait long planti ol bikpela sistem bilong kar, olsem bosim 'starter motor' long rot bilong wanpela 'ignition switch' na i no gat bikpela karent stret.
Karent Amplifikesen: Ol i save yusim ol liklik pawa signal long bosim ol hai-pawa divais (olsem ea kondisen na hetlait), na stopim ol 'circuit switch' long kisim planti pawa tumas.
Proteksen bilong Seket: Sapos i gat 'overcurrent' o sot seket, ol 'relay' inap long katim seket hariap, na lukautim ol bikpela samting bilong pawa long bagarap.
Senisim Signal: Ol 'relays' em i bikpela samting tru long senisim signal, olsem senisim ol signal bilong draiva i go long ol lait komand signal insait long ol sistem bilong tanim signal.
