Mgbe ihe fọrọ nke nta ka ọ bụrụ afọ 15 nke mmepe, ụgbọ ala eletrik ọhụrụ emepụtala ụfọdụ nkwụnye ego. Nhọrọ nkepre-charging resistorna-ekpebi ọsọ nke ụgbọ ala tupu oge a na-ebufe, nha nke oghere dị na nkwụsi ike nke mbụ, nchekwa eletrik dị elu nke ụgbọ ala, ntụkwasị obi na nkwụsi ike.
Nkwụghachi ụgwọ tupu ọ dị n'ime ụgbọ ala dị elu-voltaji ike na capacitor na mmalite nke ngwa ngwacharging resistor, ma ọ bụrụ na enweghị pre-charge resistor, chaja ugbu a ga-adị oke ibu imebi capacitor. Ike voltaji dị elu agbakwunyere ozugbo na capacitor, ya na mkpirisi mkpirisi ozugbo, oke mkpirisi okirikiri ga-emebi ihe eletriki voltaji dị elu. Ya mere, mgbe ị na-emepụta sekit, a ga-eburu n'uche nguzogide nkwụghachi ụgwọ iji hụ na nchekwa nke sekit.
E nwere ebe abụọ na elu-voltaji sekit nke eletrik ụgbọ ala ebepre-chaja resistora na-eji, nke bụ moto njikwa pre-charge circuit na elu-voltage ngwa pre-charge circuit. Onye na-ahụ maka moto (inverter circuit) nwere nnukwu capacitor, nke a ga-ebu ụzọ kwụọ ụgwọ iji jikwaa capacitor chaja ugbu a.
Dị ka n'ezie imewe nkwenye chọtara: ceramic resistor bụ ihe bara uru precharge, mwepu na ndị ọzọ chọrọ. Ọ nwere ikike ikpo ọkụ dị elu ma nwee ike ịmịnye ike dị elu n'oge a na-ebuga mbụ n'ime obere oge.
