Function of isolation transformer:
1. Primary purpose of isolation transformer is to isolate the two circuits and not to step-up or step-down the voltage.
2. The ground connection which may produce noise in sensitive and expensive instruments, the removal of ground connection is achieved by isolation transformer.
3. These transformers block the transmission of direct current (DC) signals, but allow AC signals to pass from one circuit to another.
4. These are built with special insulation between primary and secondary.
5. The isolation transformer reduces the transients of high amplitudes and short time interval