Bayan kusan shekaru 15 na ci gaba, sabbin motocin lantarki masu amfani da makamashi sun samar da wasu bayanan fasaha. Zaɓin napre-caji resistoryana ƙayyade saurin lokacin kafin cajin abin hawa, girman sararin da ke cikin juriya na caji, babban ƙarfin lantarki na abin hawa, aminci da kwanciyar hankali.
Juriya kafin caji yana cikin abin hawa babban ƙarfin wutar lantarki akan capacitor a farkon jinkirincharging resistor, idan babu pre-charge resistor, cajin halin yanzu zai yi girma da yawa don karya capacitor. Ƙarfin wutar lantarki da aka ƙara kai tsaye zuwa capacitor, daidai da gajeriyar kewayawa na gaggawa, wuce gona da iri zai lalata kayan aikin lantarki mai ƙarfi. Sabili da haka, lokacin zayyana da'ira, yakamata a yi la'akari da juriya na farko don tabbatar da amincin kewaye.
Akwai wurare guda biyu a cikin babban ƙarfin lantarki na abin hawan lantarki indapre-caji resistorana amfani da su, wanda shine keɓaɓɓen mai sarrafa motar kafin cajin da'ira da na'ura mai ƙarfi mai ƙarfi kafin caji. Mai kula da motar (inverter circuit) yana da babban capacitor, wanda ke buƙatar caji kafin caji don sarrafa capacitor cajin halin yanzu.
Dangane da ainihin tabbacin ƙira da aka samo: yumbu resistor ya fi dacewa precharge, fitarwa da sauran buƙatu. Yana da ƙayyadaddun ƙarfin zafi na musamman kuma yana iya ɗaukar makamashi mai ƙarfi yayin caji a cikin ɗan gajeren lokaci.
