China transformers, single phase transformer, three phase transformer

The transformers are mainly used to convert one voltage to another. The process of increasing the voltage is called "stepping up", while decreasing the voltage is called "stepping down". Most electronic equipments need a transformer to lower the mains voltage to a usable level. Transformers are also found in power adaptors and battery chargers. Inverters are transformers which step-up a low voltage to a higher voltage, allowing a mains powered equipment to run on a battery. Additional circuitry is required to change the battery's direct current into alternating current. Transformers are used for electricity distribution to minimize energy loss over long distances. Higher voltages allow for lower currents, which reduces the losses caused by resistance.