Toroidal transformer: leveraging the design advantage

There are many challenges when designing electronics, which is especially true for components that can be large, heavy, generate heat and create stray magnetic fields.

Toroidal transformers have many features inherent in their design that make them a useful addition to any designer’s armoury; for example, the combined features make them an ideal candidate for use in slimline-style products.

Toroidal transformer
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When compared with similar power transformer devices, a toroidal is smaller in size. While they have a similar footprint, or slightly larger, they are significantly shorter. This enables them to be suitable for inclusion in slimline-style products, with the saving as much as 50%.

They also have a simpler mounting arrangement, which only requires the use of a single bolt or screw dependant on size. They are also relatively light − around 50% the weight of laminated – and can be mounted directly onto PCBs in many cases.

Reduced stray magnetic fields

Toroidals do not create strong stray magnetic fields, which can be a major issue and often requires shielding. This issue can be compounded if your application uses analogue signals, and the issue can also affect digital circuits. Fields generated by toroids are normally less than 15% of conventional transformers.

No-load losses are very low with toroidals, making them ideal for use in products that require a low power usage while in standby mode. The voltage drop under load is also lower than with a conventional transformer.

Lower mechanical noise

Toroidals also generate much lower mechanical noise. This can be a real benefit in applications where noise is a sensitive issue, such as in office or medical applications.

Many of the benefits outlined above derive from the fact that these transformers have a much greater electrical efficiency than the traditional laminated EI style transformers. The overall energy saving can be significant over time.

In the case of designing for audio equipment, there are many aspects where toroidals provide some desirable characteristics. The generation of smaller magnetic fields is of particular interest, as is the low mechanical noise.

Many transformer manufactures, such as Siga Transformers, manufacture both types of transformer for numerous applications and markets.

Transformer selection can have an impact of the size, performance and weight of your products; therefore, selecting the correct style will ensure that you have a product that will be most desirable to your potential customers.