Transformers or Trafo, are usually used to change the form of electrical energy into other electrical energy. The energy value is changed depending on the user’s needs. The transfer of energy from one part to another at low frequencies usually uses an iron core, in which there are primary and secondary windings. When the primary winding is given an electric current, an electromagnetic field will occur in the iron core. This magnetic field will be used and converted into electrical energy in the secondary part.

The types of transformers currently available are generally used as voltage risers, voltage reducers, voltage isolation, current measurements, etc.

In applications to UPS (Uninterruptible Power Supply) systems, the transformer installed at the UPS input usually uses an isolated transformer type, where the primary and secondary windings are made separately. The use of this transformer is to isolate the main electricity network from the UPS, improve grounding voltage, reduce network interference by working as a filter, and can withstand momentary power surges on the network, such as being struck by lightning. The capacity of the transformer can vary according to the power requirements of the load.

The image above is an example of an isolated transformer diagram applied to a UPS system.