What is a toroidal transformer and what is its purpose?

Toroidal Transformer is an important type of electronic transformer with a unique circular iron core structure and windings arranged in a multi turn cylindrical configuration. Its iron core is usually seamless rolled from high-quality cold-rolled silicon steel sheets, making the iron core performance superior to traditional laminated iron cores. Due to its structural characteristics, toroidal transformers exhibit excellent performance in many aspects and are widely used in various electronic devices.

Structure and Characteristics

The iron core of a toroidal transformer is tightly wound with an equally wide silicon steel strip, forming a continuous magnetic circuit. Due to the absence of air gaps, toroidal transformers reduce excitation energy and core losses by 25% compared to laminated transformers. In addition, the coils of the toroidal transformer are uniformly wound around the iron core, and the direction of the magnetic field lines generated by the coils almost completely coincides with the magnetic circuit of the iron core, further improving efficiency.

Circular transformers have the following significant characteristics:

High electrical efficiency: Due to the absence of air gaps in the iron core, the stacking coefficient can reach over 95%, resulting in an electrical efficiency of over 95%. The no-load current is only 10% of that of the stacked structure.
Low vibration noise: The iron core has no air gap, reducing the noise of induced vibration of the iron core. The winding evenly and tightly wraps around the annular iron core, effectively reducing the “buzzing” sound caused by magnetostriction.
Low operating temperature: minimal iron loss, low temperature rise of the iron core, good heat dissipation of the winding on the iron core with lower temperature, and low temperature rise of the transformer.
Easy to install: The toroidal transformer has only one central mounting screw, making it particularly easy to quickly install and disassemble in electronic devices.
Low magnetic interference: With minimal leakage and electromagnetic radiation, it can be used on highly sensitive electronic devices without the need for additional shielding.

Classification and Usage

Circular transformers can be classified into various types based on their usage and characteristics, including standard, economical, and isolated types.

Standard power transformer: The product series has a capacity of 8-1500VA, with a small voltage regulation rate. The temperature rise during full load operation is only 40 ℃, allowing for short-term overload operation and suitable for high demand applications.
Economic power transformer: The product series has a capacity of 50-1500VA and strives to reduce costs while ensuring performance. It is suitable for continuous operation without overloading and has an operating temperature rise of 60 ℃.
Isolation Transformer: The product series has a capacity of 50-1000VA and is divided into two series: industrial and medical equipment. It focuses on insulation performance, with at least 4 layers of B-grade insulation polyester film wrapped between the primary and secondary, and a breakdown voltage greater than 4000V. Medical isolation transformers also need to comply with UL544 standards, with requirements for thermal protection and a winding to ground copper shielding distance greater than 13mm.

extensive use

Circular transformers have been widely used in various fields due to their excellent performance and cost-effectiveness

Home appliances: including audio equipment, self-control equipment, and quartz lighting. Especially in audio equipment, ring transformers are used as power transformers in high fidelity amplifiers, which can provide high-quality power.
Medical equipment: A circular transformer designed and manufactured specifically for medical devices, with high efficiency, high reliability, and high safety requirements, as well as enhanced electrical strength and resistance to moisture and heat.
Computers and Telecommunications: Used for power and signal transmission in computer systems, as well as signal amplification and isolation in telecommunications equipment.
Industrial equipment, such as current and voltage transformers, uses high-precision and high stability toroidal transformers for measurement and protection systems.
Lighting: Used as a power transformer in dimming systems and LED lighting systems to provide stable power output.

Ring type transformers not only have the advantages of high efficiency, low noise, low temperature, and easy installation, but also become an indispensable component in modern electronic devices due to their high flexibility and wide application fields. With the continuous advancement of technology and deepening of applications, toroidal transformers will continue to play an important role in various fields.