What are Toroidal Transformers?

1 Answer
Can you answer this question?

Editorial Team - everything PE

Jun 17, 2024

Toroidal transformers are a type of electrical transformer that uses a toroidal or doughnut-shaped core made up of ferromagnetic materials such as laminated iron, iron powder or ferrite. These compact transformers provide improved efficiency and design flexibility compared to conventional transformers. They are ideal for audio and medical equipment, power supplies, industrial electronics and renewable energy systems.

The operation of a toroidal transformer is similar to a linear transformer and is based on the principles of electromagnetic induction. It consists of a toroidal core surrounded by primary and secondary windings. When current flows through the primary winding, it creates an electromagnetic force (EMF) that induces a current in the secondary winding. This process enables the transfer of power from the primary coil to the secondary coil.

Features of Toroidal Transformers

Noise Level: Toroidal transformers operate quietly due to minimal vibration and electromagnetic interference (EMI).

Signal Distortion: They preserve the quality of the input signal due to low hysteresis and magnetizing current.

Core Losses: Toroidal transformers have high electrical efficiency due to minimal air gaps and effective heat dissipation.

Housing and Protection: The compact and symmetrical shape allows for easy mounting and shielding.

Dimension: Toroidal transformers are smaller and lighter than other types of transformers with the same power rating.

Efficiency: Toroidal transformers typically have an efficiency of 90 to 95%, whereas traditional transformers have an efficiency of less than 90%.

Stray Field: Toroidal transformers have a significantly lower stray field compared to traditional transformers, which reduces electromagnetic interference (EMI).

Magnetic Interference: They have a high resistance to external magnetic fields and do not emit significant magnetic interference

Mounting: Toroidal transformers can be mounted using various methods, including resin center potting, pressure-less mounting plates, complete encapsulation in plastic or metal housings, PCB mounting, and DIN rail mounting.

Encapsulation: They can be encapsulated in plastic or metal housings for added protection and shielding

              Feature                                         

Toroidal Transformers                

Conventional Transformers

Core Shape

Doughnut-shaped or ring-shaped

E-shaped or I-shaped

Core Material

Laminated iron, iron powder, or ferrite

Laminated steel

Winding Configuration

Primary and secondary windings wrapped around the core

Windings are made on a nylon bobbin and then assembled onto the core

Efficiency

90 to 95% efficient

Typically, less than 90%

Size and Weight

Smaller and lighter than conventional transformers with similar power ratings

Larger and heavier than toroidal transformers with similar power ratings

Electromagnetic Interference (EMI)

Low EMI due to compact shape and reduced magnetic flux leakage

Higher EMI compared to toroidal transformers

Mounting

Easy to mount using a single bolt

Requires multiple screws/bolts for mounting

Noise Level

Low audible noise and vibration

Higher audible noise and vibration

Applications

Suitable for low kVA (up to 15 kVA) devices in medical, industrial, renewable energy, and audio applications

Suitable for general-purpose applications due to cost-effectiveness and versatility

Cost

More expensive to manufacture

Less expensive to manufacture

Click here to learn more about Toroidal Transformers listed on everything PE.