Household electricity primarily comes from power plants. To minimize electricity loss, transformers are employed to boost the voltage to tens of thousands or hundreds of thousands of volts. Subsequently, high-voltage transmission lines transport this electricity to various destinations. However, for household appliances operating at 220 volts, the voltage must be reduced via a transformer before it can be used. A transformer consists of two coils, the primary and secondary, and voltage adjustments are achieved by altering the coil turns. Notably, transformers can only modify AC power voltage, not DC power.