Generally, the transformers operate from alternating voltages and currents so that the markings are relatively corresponding to the phase ratios between the signals in the primary and secondary circuits, taking into account that the voltages, in the same way as the currents constantly alternate their senses in order to provide a variable magnetic flux. In order to reduce losses, the core of some transformers are laminated to reduce the induction of eddy currents or Foucault in the core itself. Thus, silicon steel is used with the intention of increasing the resistivity, reducing the parasite currents.
Thus, the primary and secondary coils are enveloped on a magnetic element core of high magnetic permeability, such as an iron bench grinder core, so that the larger part of the magnetic flux passes through both coils. If an electric element is properly connected to the secondary winding, once the current and voltage applied to the primary circuit have the indicated meanings, the electric current and voltage in the component, commonly known as the circuit load, will also have specific directions.