The toroidal transformer is a large type of electronic transformer. It has been widely used in household electrical appliances and other electronic equipment with high technical requirements. Its main purpose is as a power transformer and an isolation transformer. Widely used in computers, medical equipment, telecommunications, instruments and lighting. In the past ten years, China's toroidal transformers have grown from scratch, and have formed a considerable scale of production so far, in addition to meeting domestic demand, but also a large number of exports. Domestically, it is mainly used in audio equipment and automatic control equipment for home appliances, as well as quartz lighting. The toroidal transformer is a competitive electronic transformer because of its excellent performance and price ratio, good output characteristics and anti-interference ability.
Characteristics of toroidal transformer
Toroidal transformer core is made of high-quality cold-rolled silicon steel sheet (the sheet thickness is generally 0.35 mm or less) and is seamlessly rolled, which makes its core performance superior to that of the conventional laminated core. The coil of the toroidal transformer is evenly wound around the core, and the direction of the magnetic line generated by the coil is almost completely coincident with the magnetic circuit of the core. The excitation energy and the core loss are reduced by 25% compared with the laminated type, thereby bringing the following series: The advantages.
1) The small size and light weight toroidal transformer can reduce the weight of the laminated transformer by half. As long as the cross-sectional area of the core is equal, the toroidal transformer can easily change the length, width and height of the core, and can design the required size.
2) High electrical efficiency, no iron gap, stacking factor can be as high as 95%, core magnetic permeability can be 1.5~1.8T (the laminated core can only take 1.2~1.4T), the electrical efficiency is up to 95%, no load The current is only 10% of the laminated type.
3) Easy to install the toroidal transformer Only one mounting screw in the center is especially easy to install and disassemble in electronic equipment.
4) The vibration noise is small. The iron core has no air gap to reduce the noise of the core induction vibration. The winding evenly surrounds the toroidal core, effectively reducing the "click" caused by magnetostriction.
5) The operating temperature is low. Because the iron loss can be 1.1W/kg, the iron loss is small, the core temperature rises low, and the winding heats up well on the lower temperature core, so the transformer temperature rise is low.
6) The magnetic interference is small. The toroidal core has no air gap, and the winding is evenly wound around the annular core. This structure leads to small leakage magnetic flux and small electromagnetic radiation. High-sensitivity electronic equipment can be used without additional shielding. On, for example, on low-level amplifiers and medical devices.