Transformers are devices used to transfer power between two parts of an electrical circuit, creating isolation while varying current and voltage. Transformers serve as integral components in most electrical systems.
Power transformers, in particular, are used when high-efficiency power transfer is needed. Depending on the specific application, devices may operate continuously or non-continuously at full load capacity. Like all transformers, power transformers are based on the principle of electromagnetic induction. Two magnetically coupled coils form the primary and secondary windings.
Toroidal Power Transformers
Toroidal transformers are power transformers with a toroidal core on which the primary and secondary coils are wound. When a current flows through the primary, it induces an electromotive force (EMF) and then a current in the secondary winding, thereby transferring power from the primary coil to the secondary coil.
The unique shape of the toroidal transformer allows for shorter coils, reducing resistive losses or winding losses and improving overall efficiency.
Advantages and Applications of Toroidal Power Transformers
Toroidal transformers can be much more compact than conventional power transformers of the same ratings. Plus, the improved efficiency can translate to lower temperatures.
Toroidal cores allow for 100% of the core to be used and wound upon, whereas other core shapes always have sections that need to reach around the windings to create the return magnetic path. These sections always add weight and losses that are not needed with toroidal cores.
Stray magnetic fields are created by the ends of coils, where not all magnetic field lines couple to the core. Well-constructed toroids have no end to their windings, meaning that there is no physical gap between the start and finish of the winding to allow outwardly radiated stray fields. They also have a high resistance to any external magnetic fields imposed upon them.
The compact size of toroidal transformers makes them ideally suited for applications in electronic circuits, so these transformers are often found in computers, inverters, and a multitude of similar devices. Toroidal models also hum less than conventional options, making them ideal for amplifier, television, and audio-system applications.
Toroidal power transformers are particularly well-suited for critical equipment and devices in the medical industry, as superior efficiency is important in medical systems requiring low leakage currents, noiseless and reliable operation. Since these transformers are lightweight and compact, they can be easily integrated into medical instruments in which space constraints and weight limitations are key design considerations.
