... PUSH-PULL WAY,.APPLYING FOR TYPICAL TRANSFORMER CONSTRUCTION. * EI,EE,EF CORE TRANSFORMERS HAVE A SIMPLE CONSTRUCTION,LOW MANUFACTURE ... BATCH PRODUCTION. * THE COMMON MODEL OF EE CORE TRANSFORMER INCLUDE EE-13,EE-16,EE- 19,EE-22 ... 55,EE64 ETC. * 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 EI-16,EI-19,EI- 25, EI-28 ...