What are the advantages of toroidal transformer cores?

Toroidal transformer is a large type of electronic transformer, which has been widely used in home appliances and other electronic equipment with high technical requirements. Its main purpose is as a power transformer and isolation transformer. It is widely used in computers, medical equipment, telecommunications, instruments and lighting. In the past ten years, toroidal transformers have been produced in my country. So far, they have formed a considerable scale of production. In addition to meeting domestic demand, they are also exported in large quantities. Domestically, it is mainly used for audio equipment and automatic control equipment of home appliances, and quartz lamp lighting. Toroidal transformer is a competitive electronic transformer due to its excellent performance-to-price ratio, good output characteristics and anti-interference ability.

Nanocrystalline materials also have the advantages of silicon steel, permalloy and ferrite. which is: 

  High magnetic induction: saturation magnetic induction Bs=1.2T, which is twice that of permalloy and 2.5 times that of ferrite. The core power density is large, which can reach 15kW～20kW/kg.

Features of toroidal transformer

  The current transformer cores are made of high-quality cold-rolled silicon steel sheets (thickness is generally below 0.35mm), seamlessly rolled, which makes its core performance better than traditional laminated cores. The coil of the toroidal transformer is evenly wound on the core, and the direction of the magnetic field lines generated by the coil almost completely coincides with the core magnetic circuit. Compared with the laminated type, the excitation energy and core loss will be reduced by 25%. This brings about the following series The advantages.

1) Small size and light weight Toroidal transformers can reduce the weight by half compared to laminated transformers. As long as the cross-sectional area of ​​the core is kept equal, the toroidal transformer can easily change the ratio of length, width, and height of the core, and can be designed to meet the requirements.

 

2) The high electrical efficiency iron core has no air gap, the stacking coefficient can be as high as 95% or more, the core permeability can be 1.5～1.8T (the laminated core can only take 1.2～1.4T), the electric efficiency is as high as 95% or more, no load The current is only 10% of the laminated type.

3) Easy to install the toroidal transformer has only one mounting screw in the center, which is especially easy for quick installation and in electronic equipment.

4) Less vibration and noise. The iron core has no air gap to reduce the noise of the iron core induced vibration. The winding evenly and tightly wraps the ring iron core, effectively reducing the "buzzing" caused by magnetostriction.

5) Low operating temperature. Since the iron loss can be 1.1W/kg, the iron loss is small, the temperature rise of the iron core is low, and the winding heat dissipation on the iron core with a lower temperature is good, so the temperature rise of the transformer is low.

6) There is no air gap in the toroidal transformer cores with less magnetic interference, and the windings are evenly wound on the toroidal core. This structure leads to small magnetic leakage and low electromagnetic radiation. High-sensitivity electronic equipment can be used without additional shielding. For example, it is used in low-level amplifiers and medical equipment.