1. Voltage Conversion: A transformer converts the voltage of an input circuit into the voltage required by the output circuit. When the output winding of a transformer has more turns than the input winding, it is called a step-up transformer; conversely, when the output winding has fewer turns than the input winding, it is called a step-down transformer. Through the voltage conversion function of a transformer, the appropriate voltage supply can be provided according to different requirements.
2. Current Conversion: A transformer can also change the current level as needed. When the output winding has more turns than the input winding, the output current is lower; conversely, when the output winding has fewer turns than the input winding, the output current is higher. This current conversion property enables transformers to perform current matching and power transmission functions in power systems.
3. Isolation and Coupling: Transformers completely isolate the input and output circuits through their insulated core and windings, achieving electrical isolation. This isolation provides safety and protection, preventing current and noise from propagating into other circuits. Furthermore, transformers can be used to couple two circuits for signal transmission and impedance matching.