A 1895, Jamus Overtone ya samar da farko a duniyaDC lantarki rawar soja. An yi harsashi da baƙin ƙarfe na siminti kuma yana iya haƙa ramukan 4mm a cikin farantin karfe. Daga baya, mitar wutar lantarki mai hawa uku (50Hz) ta bayyana, amma saurin motar ya kasa wuce 3000r/min. A cikin 1914, kayan aikin lantarki waɗanda ke tafiyar da injunan jeri guda ɗaya sun bayyana, kuma saurin motar ya kai fiye da 10000r/min. A cikin 1927, kayan aikin lantarki na tsaka-tsaki tare da mitar wutar lantarki na 150 zuwa 200 Hz ya bayyana. Ba wai kawai yana da fa'idar babban saurin saurin jerin motoci guda-ɗaya ba, har ma yana da fa'idodi na injin mitar wutar lantarki mai sauƙi da abin dogaro uku. Koyaya, yana buƙatar kawota tare da mitar halin yanzu. , An iyakance amfani.