Lub hauv paus ntsiab lus ntawm kev ua haujlwm ntawm lub tshuab hloov pauv yog tias nws cov tub ntxhais yog lub zog siv zog rau cov hlau nplaum, yog li cov windings "lub hom phiaj" ua rau muaj qhov tsis zoo ntawm cov hlau nplaum. Ib qho autotransformer muaj ib feem winding thiab ib qho me me winding tsuas yog siv rau ntawm ib sab. Lub magnetisation los ntawm qhov me me winding seem yuav tsum tau offset tias los ntawm ib feem winding, yog li nws yuav nqa ib proportionally loj tam sim no. Ib qho kev hloov pauv kom zoo yuav muaj ntu ntu ob zaug, thiab feem ntau tshem tawm cov hlau nplaum muaj nyob hauv ob qho tib si. Qhov ntawd ua rau muaj kev poob loj loj dua yog tias cov dej ntws tuaj yeem tshem tawm ua ntej txawm tig mus rau hauv kev sib nqus.
Tab sis muajyogib qho tsis tshua muaj winding seem, thiab nws cov magnetization yuav tsum tau tshem tawm nrog cov magnetisation los ntawm cov seem winding. Qhov ntawd tseem txhais tau tias tseem ceeb tam sim no ntws.
