Toroidal Transformers

Overview and applications

Toroidal transformers are a major electronic-transformer type used in domestic appliances and equipment with demanding technical requirements, principally as power and isolation transformers. The brochure describes established overseas ranges used in computers, medical equipment, telecommunications, instrumentation and lighting.

The brochure describes growth in Chinese production over the preceding decade, supplying domestic demand and exports. Listed domestic applications include audio equipment, automatic-control equipment and quartz-lamp lighting. Competitive cost/performance, output characteristics and interference resistance are highlighted.

Features

The ungapped core has a stated stacking factor above 95%. The brochure prints a core “permeability” figure of 1.5–1.8 T versus 1.2–1.4 T for a laminated core; T is retained as printed. It states efficiency above 95% and no-load current approximately 10% of the laminated-core equivalent.

Small size and low weight: the brochure states that weight may be reduced by half compared with a laminated transformer. Keeping core cross-section constant allows the proportions to be changed to meet dimensional requirements.

Low magnetic interference: windings are uniformly distributed on an ungapped toroidal core, reducing leakage flux and electromagnetic radiation. The brochure describes use in sensitive electronic equipment, low-voltage high-current generators and medical equipment without additional shielding.

Reduced vibration and noise are attributed to the absence of core air gaps.