Toroidal Transformers

What is Transformer?
A transformer is a device that transfers electrical energy from one circuit to another by magnetic coupling without requiring relative motion between its parts. It usually comprises two or more coupled windings, and, in most cases, a core to concentrate magnetic flux.

An alternating voltage applied to one winding creates a time-varying magnetic flux in the core, which induces a voltage in the other windings. Varying the relative number of turns between primary and secondary windings determines the ratio of the input and output voltages, thus transforming the voltage by stepping it up or down between circuits.

The transformer principle was demonstrated in 1831 by Faraday, though practical designs did not appear until the 1880s.[1] Within less than a decade, the transformer was instrumental during the "War of Currents" in seeing alternating current systems triumph over their direct current counterparts, a position in which they have remained dominant. The transformer has since shaped the electricity supply industry, permitting the economic transmission of power over long distances. All but a fraction of the world's electrical power has passed through a series of transformers by the time it reaches the consumer.

What is Toroidal Transformer?
Toroidal transformers are built around a ring-shaped core, which is made from a long strip of silicon steel or permalloy wound into a coil, from powdered iron, or ferrite, depending on operating frequency. The strip construction ensures that the grain boundaries are optimally aligned, improving the transformer's efficiency by reducing the core's reluctance. The closed ring shape eliminates air gaps inherent in the construction of an
E-I core. The cross-section of the ring is usually square or rectangular, but more expensive cores with circular cross-sections are also available. The primary and secondary coils are often wound concentrically to cover the entire surface of the core. This minimises the length of wire needed, and also provides screening to minimize the core's magnetic field from generating electromagnetic interference.

Ferrite toroid cores are used at higher frequencies, typically between a few tens of kilohertz to a megahertz, to reduce losses, physical size, and weight of switch-mode power supplies.

Toroidal transformers are more efficient than the cheaper laminated E-I types of similar power level. Other advantages, compared to E-I types, include smaller size (about half), lower weight (about half), less mechanical hum (making them superior in audio amplifiers), lower exterior magnetic field (about one tenth), low off-load losses (making them more efficient in standby circuits), single-bolt mounting, and more choice of shapes. This last point means that, for a given power output, either a wide, flat toroid or a tall, narrow one with the same electrical properties can be chosen, depending on the space available. The main disadvantages are higher cost and limited size.

When fitting a toroidal transformer, it is important to avoid making an unintentional short-circuit through the core. This can happen if the steel mounting bolt in the middle of the core is allowed to touch metalwork at both ends, making a loop of conductive material that passes through the hole in the toroid. Such a loop could result in a dangerously large current flowing in the bolt.

Advantages of Toroidal URVI Transformers :
* Toroidal Transformer offer many advantages over a conventional laminated transformer. Toroidal has a round shape with no air gaps, and with the primary and secondary windings uniformly distributed around the core, "locks in" the magnetic field and makes the toroidal transformer very quiet and efficient.

* Toroidal Transformer,by meeting today's requirements for smaller,more efficient,quieter and safer products,are being accepted in an increasing range of electronic and electrical equipment. With toroidal transformer smaller dimensions, lighter weight and low stray magnetic fields,you can build more compact,lower cost quality products without sacrificing performance.

Toroidal Transformer Features :
>> Hi Efficiency
>> Better Regulation
>> Least Leakage Flux
>> Absence of External Magnetic Field
>> Less Magnetising Current
>> No Humming Noise
>> Low Temperature Rise
>> CRGO Silicon Steel Core
>> Efficient Colling
>> Light in Weight
>> Compact Size
>> Easy Mounting