Isolation Transformers

An isolation transformer is used to transfer power from a source of alternating current (AC) power to an attached electronic device while isolating the powered device from the original power source.

Isolation transformers provide galvanic isolation and protect against electric shock. They suppress electrical noise in sensitive devices and transfer power between two circuits that must not be directly connected. 

Isolation transformers are also used to protect secondary circuits and individuals from electrical shocks between powered conductors and earth ground. They also block interference caused by ground loops. Isolation transformers with electrostatic shields are used for sensitive electronics such as computers, medical devices, or laboratory instruments.