An analysis has been performed of charged transmission‐line configurations for use in high‐current electron accelerators. Conditions for maximum efficiency and maximum energy transfer to the beam load are derived for ideal constant‐impedance lines. It is shown that, in the lossless‐line approximation, asymmetric line‐pair configurations exist with which both a high accelerating voltage and nominal 100&percent; efficiency can be achieved. The configurations would also have application as a pulse‐forming network for use with other switched loads.