Toroidal Core

The shape of the core is such that the magnetic field of the toroid is contained within itself. Hence there’s no radiation of stray magnetic flux and the Transformer can be placed in high density electronic circuitry without any interfering hum. Leakage inductance and stray capacitance are also very small. And when the Toroidal Transformer is placed in an interfering field, the interfering forces tend to act equally all around the toroid, resulting in the cancellation of interfering voltages in the coils in a manner similar to the astatic windings.