... Frequency Transformers FEATURE * EI,EE,EF CORE TRANSFORMERS HAVE BEEN WIDELY USED ... APPLYING FOR TYPICAL TRANSFORMER CONSTRUCTION. * EI,EE,EF CORE TRANSFORMERS HAVE A SIMPLE CONSTRUCTION,LOW MANUFACTURE ... . * THE COMMON MODEL OF EF CORE TRANSFORMER INCLUDE EF-16,EF-20,EF- 25, EF-32 ETC. * THE COMMON ... MODEL OF EF CORE TRANSFORMER INCLUDE ...