Voltage transformers form a unique family within the world of transformers. They are used to convert the voltage to match the input voltage of the measuring instrument and to achieve galvanic isolation.
They are intended to convert a voltage signal in measuring devices, energy meters, relays and other analogue or digital equipment. Voltage transformers ensure a very limited load on the circuit to be measured and are extremely accurate in converting voltages from primary to secondary over the full range, from zero load to full load. The secondary voltage is almost perfectly proportional to the primary voltage and the phase shift, with respect to the primary voltage, is virtually zero.