Versatile Application

The application of toroidal power transformers is similar to that of traditional transformers. Most traditional circuits and calculations for rectification and filtering apply. Toroidal transformers can be designed in many sizes with a variety of secondary and primary windings, special electrostatic shielding, stray field protection, and mounting configurations.

The core of the toroidal transformer is made of a grain-oriented silicon steel strip wound under controlled tension into a "donut." It is mechanically very solid and stable. Because of the way primaries and secondaries are wound uniformly around the core and the fact that toroids have no air gaps, there is very low emission of stray magnetic fields or EMR (Electro-Magnetic Radiation).

• Smaller Size and Weight

Toroid's higher efficiency than laminated type transformers can save up to 50% in weight and size. This helps simplify the design of cabinets, mechanical geometry, and mounting configuration. It suits the trend for smaller, more compact electrical and electronic products.

The diameter-to-height ratio of a toroid can easily be varied (as long as area of the cross section is held constant) to suit the mechanical design. This is great for low profile equipment.

• Low Stray Magnetic Fields

Toroids emit very low radiated magnetic fields, typically 1/8 the level of the conventional E/I lamination type. For most applications no special shielding is needed. This suits toroidal power transformers for applications in sensitive electronic equipment, such as low level amplifiers, medical equipment, and in equipment with CRTs. When further reduction of the EMR is needed, a magnetic shield around the circumference of the transformer can be provided. Encapsulation in a steel can reduces hum and adds a cosmetic benefit.

• Low Mechanical Noise (Hum)

The uniform windings enveloping the core greatly reduce magnetostriction - the main source of the familiar "hum" found in conventional laminated transformers. Compared to those models, our toroidal power transformer is silent. This makes ours ideal for hospital and office environments, where an annoying hum would be unacceptable.

• Electrical Efficiency

There are two important reasons why a toroidal transformer is more efficient than the conventional E/I lamination type. One is that the high quality grain oriented steel is utilized at close to 100% in all areas of the core. As a result the core may operate at 15-16 kilogauss versus 12 to 14 kilogauss in the E/I design. There are no air gaps which means a no-load current draw of about 10% of that of a stacked lamination construction. The other reason is that the windings are distributed over the entire core circumference which reduces the mean length of copper wire per turn in comparison with the E/I transformer, the windings on which are located only on parts of its steel core. Accordingly, a toroidal design requires less steel and copper wire with less core and copper losses resulting in energy savings.

• Reduced No-Load Losses

Compared to conventional E/I transformers, toroidal power transformers exhibit extremely low no-load losses. In applications where a circuit sits in a "stand-by" mode for long periods, the energy cost savings can be significant. Lower operating temperature may also be beneficial.

• Voltage Regulation

The voltage drop under load (regulation) is much lower than that of a conventional transformer. Increasing the core size can further reduce voltage drop.

• Easy to Mount

A single center screw quickly and easily mounts a toroidal transformer. Compared to laminated transformer mounting, this cuts down on parts as well as assembly time in your product.