The transformer mainly uses the principle of electromagnetic induction to work. When an alternating current is passed through the primary coil, an alternating magnetic flux is generated in the iron core (or magnetic core) to induce a voltage (or current) in the secondary coil. The transformer consists of a core (or core) and a coil. The coil has two or more windings. The winding connected to the power supply is called the primary coil, and the other winding is called the secondary coil. The transformer boosting process is specifically: when the alternating voltage U1 is applied to the primary side of the transformer, and the current flowing through the primary winding is I1, the current generates an alternating magnetic flux in the iron core, so that the primary winding and the secondary winding are electromagnetically connected. According to the principle of electromagnetic induction, the alternating magnetic flux passes through the two windings and induces an electromotive force. The magnitude of the alternating magnetic flux is proportional to the number of winding turns and the maximum value of the main magnetic flux. The voltage on the side with a large number of winding turns is high, and the number of winding turns is high. The voltage on one side is low. When the secondary side of the transformer is open, that is, when the transformer is unloaded, the voltage of the secondary terminal is proportional to the number of turns of the secondary winding, that is, U1/U2=N1/N2, but the primary and secondary frequencies. Keep consistent to achieve voltage changes.