Voltage oba current ezimu bwe ziteekebwa okubuna koyilo ya relay ya masanyalaze, ekisengejjo kya magineeti ekikolebwa koyilo kiyita mu nkulungo ya magineeti ekoleddwa omusingi gw’ekyuma, ekikoligo, armature, n’ekituli ky’empewo ekola. Wansi w’okufugibwa ekifo kya magineeti, ekisumuluzo kisikirizibwa ku ffeesi y’ekikondo y’omusingi gw’ekyuma, bwe kityo ne kinyigiriza ebikwatagana ebiggaddwa mu ngeri eya bulijjo okugguka ate ebikwatagana ebiggule bulijjo okuggalawo. Voltage oba current okubuna koyilo bweba wansi w’omuwendo ogugere, empalirizo y’ensengekera y’ebyuma eba nnene okusinga empalirizo y’okusika kw’amasannyalaze, armature edda mu mbeera yaayo eyasooka, enkolagana eziggule eza bulijjo zigguka, ate enkolagana eziggaddwa bulijjo ziggalwa.
N’olwekyo, relay y’emmotoka esobola okutunuulirwa ng’ekibiina ekirimu ekiyungo ekifuga ekikola ne koyilo n’ekiyungo ekikulu ekikola n’ebikwatagana. Mu circuit y’okufuga eya relay, akasannyalazo akatono akakola ke kabaawo. Kino kiri bwe kityo kubanga obusobozi bw’okukwatagana (contact capacity) bwa switch ekola butono era tebusobola kukozesebwa kufuga butereevu migugu nga girina obwetaavu bw’amasannyalaze amangi; embeera yaayo eya on/off esobola okufugibwa okuyita mu relay contacts zokka.
Relay ye switch y’okufuga n’ekintu ekifugibwa (actuator). Nga tutwala relay ya ppampu y’amafuta ng’ekyokulabirako, ye switch efugira ppampu y’amafuta, naye coil ya relay ya pampu y’amafuta esobola okukola circuit yokka okuyita mu grounding point ya electronic control unit (ECU) nga driving transistor mu ECU ekoleezeddwa.
