Ajigilar kayawani ɓangare ne na lantarki wanda ke amfani da ƙa'idodin lantarki ko wasu tasirin jiki don cimma "kunnawa/kashewa ta atomatik" na da'irori. Babban aikinsa shine sarrafa kashewa na manyan da'irori na lantarki/babban ƙarfin lantarki tare da ƙananan wutar lantarki/sigina, yayin da kuma cimma warewar lantarki tsakanin da'irori don tabbatar da amincin ƙarshen sarrafawa.

Ana iya rarraba manyan ayyukansa zuwa rukuni uku:

1. Sarrafawa da Ƙarfafawa: Yana iya canza siginar sarrafawa mara ƙarfi (kamar fitowar kwararar matakin milliampere ta ƙananan kwamfutoci da firikwensin kwamfuta ɗaya) zuwa kwararar lantarki masu ƙarfi waɗanda suka isa su tuƙa na'urori masu ƙarfi (kamar injina da masu dumama), suna aiki a matsayin "amplifier sigina". Misali, a cikin gidaje masu wayo, ƙananan siginar lantarki da manhajojin wayar hannu ke aikawa ana iya sarrafa su ta hanyar relay don kunnawa da kashe wutar kwandishan da fitilun gida.

2. Warewa ta lantarki: Babu haɗin lantarki kai tsaye tsakanin da'irar sarrafawa (ƙarancin wutar lantarki, ƙaramin wutar lantarki) da da'irar da aka sarrafa (babban wutar lantarki, babban wutar lantarki). Ana watsa umarnin sarrafawa ne kawai ta hanyar siginar lantarki ko na gani don hana babban wutar lantarki shiga tashar sarrafawa da lalata kayan aiki ko kuma sanya haɗarin lafiyar ma'aikata. Wannan galibi ana samunsa a cikin da'irar sarrafawa na kayan aikin injin masana'antu da kayan aikin wutar lantarki.

3. Manhaja da Kariya: Ana iya haɗa shi don aiwatar da dabaru masu rikitarwa na kewaye, kamar kullewa (hana injina biyu farawa a lokaci guda) da jinkirta sarrafawa (jinkirin haɗin nauyin na wani lokaci bayan kunnawa). Wasu na'urorin relay na musamman (kamar na'urorin relay na overcurrent da na'urorin relay na overheating) suma suna iya sa ido kan matsalolin da ke kewaye. Idan wutar lantarki ta yi girma sosai ko kuma zafin ya yi yawa, za su yanke da'irar ta atomatik don kare kayan lantarki daga lalacewar da ke wuce gona da iri.