What is the Difference between conventional transformer and toroidal transformer?

Answer 1

Conventional Transformers have rectangular cores, whereas toroidal transformers have circular ('toroid' means 'circular') cores. The windings are placed around conventional cores by removing the top 'yoke' (horizontal member) of the core, making them easy to manufacture. For a toroidal transformer, however, the windings have to be actually wound around the core, making them much more difficult and, therefore, expensive to manufacture. Toroidal cores have less magnetic leakage than conventional cores, but are limited to small applications (e.g. hi-fi amplifiers, etc.), whereas conventional cores can be manufactured to any size.