Why is the transformer ah?
The AC power up and down operation. The So as to get the desired AC voltage
Transformer principle is based on the principle of electromagnetic induction made, the transformer has two separate coil sharing a core. Respectively, called the primary coil and secondary coil. When the direction and size of the alternating current change with time, when the transformer is connected to the alternating current, the alternating magnetic field is generated in the core of the transformer, and the AC voltage of the same frequency is induced in the secondary. The turns ratio of the primary winding of the transformer Equal to the voltage ratio. Transformer can only change the AC voltage, can not change the DC voltage, because the DC direction and size is constant, through the transformer will not produce alternating magnetic field.
Transformers are electrical components used to change the voltage. In the circuit, you can raise the voltage, you can also reduce the voltage to achieve the required voltage value. The voltage transformer is called a step-up transformer, on the contrary, called a step-down transformer. Of course, the transformer can only change the AC voltage (mains, etc.), can not change the DC voltage (battery, battery, etc.).
