Current sense transformers are a type of instrument transformer that are used to measure current values in a conductor, mainly used in high-current circuits. In such transformers, the primary has very few windings and is connected in series with the conductor carrying the current that is to be measured. This is why current sense transformers are also known as series transformers. The secondary, on the other hand, has many windings wound around a ferromagnetic core. These transformers are easy to implement, accurate, and reliable under even the harshest environmental and thermal conditions. An ideal current sense transformer has zero winding resistances, infinite inductance, perfect coupling and no parasitics.
