Toroidal coils are electrical components that consist of a
doughnut-shaped metallic core that has a conducting metal wire looped or
coiled around it in order to form an inductor. An inductor stores
electrical energy through the production of a magnetic field and
introduces that stored energy flow into the metallic core. The most
common material used to form conductive metal wire is copper, while the
metallic core is typically manufactured using materials such as solid
iron, solid steel or powdered iron due to their ferromagnetic
Toroidal coils offer both a higher inductance and a higher "Q" factor, which refers to the measurement of the efficiency of the coil's inductive reactance to its resistance at a set frequency, than solenoid coils. Able to be used for a wide range of applications, toroidal coils are necessary components in many industries just as its fellow coils, induction, choke and magnetic are: power generation, for use in power transformers, current transformers and more; electronics, for use in energy meters for testing of radio equipment and more; and industrial manufacturing, for use in instrument transformers, high-frequency coils and switched-mode power supply (SMPS) transformers for power supply control. Although many types of electrical coils are used in these and other industries, their uses vary depending on the coil itself. Just one example of the variance is how the choke coil serves to protect power lines while the toroidal works in the actual transformers. This group of tools is very versatile.
Toroidal coils are easily distinguished from the various other types of electric coils because of their unique design. Instead of having a cylindrical core, toroidal coils have a doughnut-shaped core that the wire is wrapped around in very small coils. With a smaller number of turns required, the toroidal coil is able to provide a closed magnetic path. This means that the magnetic flux of the coil is primarily confined to the coil's core, thus preventing the energy provided from being absorbed by any objects in close proximity to the coil. As a result, toroidal coils are pretty much able to serve as a self-shield and do not require external shielding unlike many other types of electric coils. The magnetic flux of the toroidal coils occurs as a result of an alternating current flowing through the coil. An alternating current varies from a direct current in that the current flow will periodically change direction, whereas a direct current maintains one singular direction of current flow. In addition, the magnetic flux of the coil changes in proportion to changes in the current. Toroidal coils can be manufactured with or without a base, and when manufactured with a base may be mounted either horizontally or vertically.
Toroidal Coils - Sag Harbor Industries, Inc.