Telecom transformers can serve a variety of roles. For example, they can function as isolation transformers, preparing the voltage before transmission across telecom cables or adjusting the voltage so that it is suitable for a low-voltage application inside the home.
The telecom transformer is one of the most common and vital components in any telecommunications system. Other types of equipment, such as resistors and capacitors, are sometimes used to achieve the same goals that a telecom transformer achieves. However, telecom transformers perform these tasks with a greater degree of efficiency and ease of use, and thus are more commonly used than their alternatives.
Telecom transformers are designed with different types of inductance, mounting styles and other specifications that dictate whether those devices will be appropriate for a given application or use in a given device.
They can be mounted in different ways. Some designs are surface mounted, while others are mounted through the holes in a breadboard.