A toroidal transformer is a special type of electrical transformer with a doughnut-like shape. Toroidal transformers provide increased design flexibility, efficiency, and compactness when compared to traditional shell and core type transformers. They are an ideal solution for low-KVA (up to 15 KVA) rated devices and equipment used in medical, industrial, renewable energy, and audio applications.

A toroidal transformer operates under the principles of electromagnetic induction similar to a linear transformer. It features a toroidal core surrounded by primary and secondary windings. As current flows through the primary winding, it produces an electromagnetic force (EMF) that generates a current in the secondary winding; this process allows power to be transferred from the primary coil to the secondary coil.