The use of ac voltage from power station to long distance and to run different electrical devices of different voltage rating , the voltage should either to increase or to decrease. For this transformer is needed. Without the transformer, there is no change in ac voltage. So the use of ac current is limited.
A transformer is an electrical device that uses electromagnetic induction to pass an alternating current (AC) signal from one electric circuit to another, often changing (or "transforming") the voltage and electric current. ... Transformers are also used as a part of devices, like current transformers.When applying AC current to the primary winding of the transformer, the coil creates a pulsing magnetic field. ... Once the magnetic field reaches the secondary coil, it forces the electrons within it to move, creating an electric current via electromotive force (EMF).
A transformer is used to bring voltage up or down in an AC electrical circuit. A transformer can be used to convert AC power to DC power. There are transformers all over every house, they are inside the black plastic case which you plug into the wall to recharge your cell phone or other devices.The transformer, located inside of the house on the furnace or fan coil unit for the air-conditioning, is a small black or brown electrical component that is normally located on the inside of the furnace or mounted just outside the furnace.
DC power is significantly more energy efficient than AC power. DC motors and appliances have higher efficiency and power to size characteristics. ... The greater efficiency resulting from recent developments in DC converter technology allows improvements in electricity delivery over long distances.A transformer is not designed to convert AC to DC or DC to AC. The transformer can step-up or step -down current. A transformer that increases the voltage from the primary to secondary is called a step-up transformer.Transformer is built only for AC current.