Masu samar da wutar lantarki masu samar da wutar lantarki suna tunatar da ku cewa tare da ci gaba da haɓakar fasaha, sannu a hankali an fara amfani da masu sauya mitar a rayuwarmu ta yau da kullun, kamar kwandishan, lif, da masana'antu masu nauyi. Amfani da fasahar mitar mitar mai canzawa a cikin kwandishan ya zama sananne ga mutane, amma akwai ƙarancin sani game da amfani da fasahar mitar mitar a cikin lif.
A halin yanzu, yawancin lif suna amfani da ka'idojin saurin mitar mai canzawa da ka'idojin saurin wutar lantarki, tare da masu canza mitar suna lissafin kusan rabin lif. Mafi yawan mizanin lif shine allon dabaru+ mai jujjuyawa. Tsohuwar ita ce ma'aikacin da ke sa ido kan yadda kowane sigina a cikin lif, yayin da na karshen ya ƙunshi gabaɗayan injin farawa da masu kunna birki. Bari mu fara da mafi ilhama na waje kewaye. Da fari dai, mai sauya mitar na iya cimma tsarin saurin motsi na motar ta hanyar haɗa manyan wayoyi uku na motar: R, S, da t. Don samun zurfin fahimtar ƙa'idar ƙa'idar saurin juyawa ta mitar, ɗaukar motar asynchronous mai hawa uku a matsayin misali, a cikin siminti na matakai uku na iskar gas na injin asynchronous mai hawa uku, an samar da filin maganadisu mai jujjuya, wanda ke yanke madubin rotor kuma yana haifar da halin yanzu a cikin iskar rotor. Halin da ake ciki yanzu zai sa jujjuyawar rotor ya haifar da ƙarfin filin maganadisu mai jujjuyawa, wanda hakan zai motsa rotor ɗin don juyawa. Mitar fitarwa tana ƙayyade saurin jujjuyawar filin maganadisu mai jujjuyawa, don haka samun ƙa'idar saurin na'ura mai juyi. Akwai dabara don saurin daidaitawa n=60f/p, wanda ke da alaƙa da wannan. Tabbas, wannan matakin yana nufin adadin iskar stator. Yawancin lokaci muna samun cewa ƙarfin wutar lantarki na inverter a menu na inverter yana da girma ko ƙasa daidai, saboda a mitar da aka ƙididdigewa, idan mitar ƙarfin lantarki ya ragu a wasu yanayi, zai haifar da magnetism mai ƙarfi har ma ya ƙone motar. A daya bangaren kuma, idan magudanar ruwa bai isa ba, kai tsaye zai haifar da karfin fitar da injin lantarkin.
Babban da'irar mai sauya mitar mitar ta ƙunshi sassa uku: da'irar gyara, da'ira mai tsaka-tsaki, da da'irar inverter. Da'irar gyara tana da sauƙi kuma kai tsaye tana wucewa ta gada mai gyara sau uku (power diode uncontrolled rectifier, thyristor control uncontrolled rectifier) don halin yanzu kai tsaye, wanda kuma aka sani da wutar bas DC. Lokacin da aka yi amfani da tsaka-tsakin da'irar da'irar gyarawa da da'irar inverter, gami da da'irori na gaba ɗaya, na'urorin tacewa, da tubalan birki, injin inverter zai iya ganin babban capacitor wanda ke aiki azaman mai sarrafa matattara. Domin har yanzu ana buƙatar tacewa mai gyara pulsation DC, zai iya samar da ingantaccen wutar lantarki na DC. Hakanan ana amfani da akwatin resistor na waje na inverter module. A cikin wannan babban ƙarfin, lokacin da mai watsa shiri ya rage kuma ya birki, motar za ta shiga cikin janareta, kuma wutar lantarki na iya adana makamashin lantarki a cikin babban capacitor. Lokacin da aka tilasta masa matsar da saitunan wuta da yawa, mai inverter yana sarrafa resistor na waje don cinye ƙarfin da ya wuce kima, ta haka yana guje wa mai canza ƙarfin wuta. A ƙarshe, da'irar inverter ita ce mafi mahimmanci kuma mafi raunin ɓangaren inverter. Gabaɗaya hanyoyin sarrafa mitar mitar sun kasu kashi biyu: PAM (Pulse Amplitude Modulation) da PWM (Pulse Width Modulation). Koyaya, PAM kuma yana buƙatar daidaitawa tare da da'irori masu daidaitawa a cikin wasu masu sauya mitar, waɗanda ke buƙatar buƙatu masu fa'ida kuma suna da manyan lahani. Ikon PWM shine hanyar da aka fi amfani da ita. Modulation PWM na'ura ce mai sauyawa bisa manyan da'irori inverter, wanda ke sarrafa lokacin daidaitawar mitar fitarwa ta hanyar canza girman bugun bugun jini. Yanzu ana amfani da shi a cikin ƙarin na'urori masu sauyawa kamar IGBT, sannan kuma yana rinjayar motar (inductive load) tare da ƙananan bugun jini, yana taimakawa wajen samar da raƙuman ruwa da sarrafa wutar lantarki da mita, don haka cimma matakan saurin gudu.
Mai sauya mitar elevator ba kayan aiki ne na musamman don sarrafa lif ba, har ma babban samfuri ne a tsakanin ƙananan masu sauya wutar lantarki da matsakaici. Yana inganta haɓakar lif, yana gudana ba tare da matsala ba, kuma yana ƙara tsawon rayuwar kayan aiki. Haɗe tare da PLC ko sarrafa microcomputer, yana ƙara nuna fifikon kulawar da ba ta da lamba: sauƙaƙe wayoyi, sarrafawa mai sassauƙa, ingantaccen aiki, da kulawa mai dacewa da kulawa da kuskure. Shigar da na'urar ceton makamashi ta elevator akan mai sauya mitar lif zai iya yadda ya kamata ya canza ƙarfin wutar lantarki da aka sabunta da aka adana a cikin capacitor na mitar mitar lif zuwa wutar lantarki ta AC sannan a mayar da shi cikin grid ɗin wutar lantarki, yana mai da lif zuwa wani kore "masana wutar lantarki" don samar da wutar lantarki ga wasu kayan aiki da kuma ceton makamashi.