What type of transformer would you use to decrease the voltage for household devices?

The use of a step-down transformer is essential in reducing voltage levels suitable for household devices. Household appliances typically operate at lower voltage levels, such as 120V or 240V, while electrical power lines carry much higher voltages, often in the range of thousands of volts. A step-down transformer alters the voltage by having a higher number of turns on the primary winding compared to the secondary winding. This design effectively decreases the voltage while increasing the current, making it safe and practical for everyday devices like toasters, televisions, and computers to operate efficiently without the risk of damage from excessive voltage.

Other types of transformers serve different purposes; for instance, a step-up transformer increases voltage, an isolation transformer provides safety by isolating the electrical load from the power source, and a phase-shifting transformer is used primarily to manage power flow in electrical grids. None of these are suitable for reducing voltage for common household use.