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 such materials as solid iron, solid steel, or powdered iron due to their ferromagnetic capabilities.
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Applications of Toroidal Coils
Toroidal coils offer both a higher inductance and a higher "Q" factor than solenoid coils. A "Q" factor refers to the measurement of the efficiency of the coil's inductive reactance to its resistance at a set frequency. 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.
Toroidal coils are often used in these applications:
- Power Generation
- For use in power and current transformers.
- For use in energy meters for testing of radio equipment.
- 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.
Characteristics of Toroidal Coils
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.