Power over Ethernet (PoE) Transformers Würth Elektronik PoE Transformers are flyback transformers designed for Power over Ethernet (PoE) applications. These PoE transformers are available in a wide variety of options to cover the range of power requirements for powered devices. The variants include WE-PoE, WE-PoE+, WE-PoEH, MID-PoE, MID-PoELT, and MID-PoETI. The PoE transformers use forward / flyback topology and are compatible with IEEE PoE standards.