Makina obowola amtunduwu amapangidwa ndikupangidwa motsatira miyezo ya API.
Zopangira pobowola izi zimagwiritsa ntchito makina oyendetsa a AC-VFD-AC kapena AC-SCR-DC ndipo kusintha kopanda masitepe kumatha kuzindikirika pazojambula, tebulo lozungulira, ndi pampu yamatope, yomwe imatha kugwira ntchito bwino pakubowola bwino. ndi maubwino otsatirawa: kuyambitsa modekha, kuyendetsa bwino kwambiri komanso kugawa magalimoto.