Toroidal Transformers

Toroidal Transformers has one winding that is tapped at one or more points along the length of this winding. Voltage is applied across a portion of the winding, and a higher or lower voltage is produced across another portion of the same winding.
Since the primary and secondary circuits have a number of windings turns in common, the volts-per- turn is the same in both the circuits. Each develops a voltage in proportion to its number of turns. One part of the current flows directly from the input to the output, and the other part is transferred inductively, allowing a smaller and lighter core to be used.
Toroidal Transformers are used in a wide range of electronic circuits: power supplies, inverters, and amplifiers, which in turn are used in the vast majority of electrical equipment: TVs, radios, computers, and audio systems.
Toroidal Transformers are used to step-up or step-down the voltages in 110-115- 120 V range and 220-230- 240 V range. For example, providing 110-120 V (with taps) from 230 V input, allowing equipment designed for 100-120 V input to be used with a 230 V supply. This allows US electrical equipment to be used in the higher European supply voltage. Toroidal Transformers can also be used to run European 230 V appliances from a 100 or 120 V supply source in countries outside Europe.
Toroidal Transformers have many advantages over conventional double wound Transformers. They are generally more efficient for the same VA rating, are smaller in size, and as they require less copper in their construction, their cost is less compared to double wound Transformers of the same VA rating. Also, their core and copper losses, I 2 R are lower due to less resistance and leakage reactance giving a superior voltage regulation than the equivalent two winding Transformers.