Superelectrons passing through the weak link region of Josephson junctions are affected by the electric potential applied to this region, and are accelerated or decelerated. The effect would appear as the modulation of the supercurrent through the junction. The amount of the supercurrent is calculated using the time‐dependent Ginzburg–Landau equation for the device structures of superconductor‐insulator‐normal conductor‐insulator‐superconductor where the intermediate normal region is used to introduce the electric potential.