E型和E1型铁心是目前使用得最多的铁心，它的主要优点是绕组的初、次级可共用一个骨架.有较高的窗口占空系数.铁心可对绕组形成保护外壳，使绕组不易受机械创伤。
E-type and E1-type cores are the most widely used cores at present. Their main advantages are that the primary and secondary windings can share a common skeleton. They have higher window duty factor. The core can form a protective shell for the windings, so that the windings are not susceptible to mechanical trauma.
另外铁心的散热面积也较大，本身磁场发散也较少辛但它也有缺点，如磁路中气隙较大，增加磁阻，使磁路性能降低。除此之外，它还存在着铜线多、漏感大和外来磁场干扰大的缺点。
In addition, the heat dissipation area of the core is larger, and the magnetic field divergence is less symplectic, but it also has shortcomings, such as the larger air gap in the magnetic circuit, the increase of magnetoresistance, which reduces the performance of the magnetic circuit. In addition, it also has the disadvantages of more copper wires, large leakage inductance and large external magnetic field interference.