A Josephson junction has been realized in which the supercurrent flow is regulated by a “normal” control current traversing the normal metal in between the superconducting electrodes. The principle of operation of the devices is based on the existing relation between the magnitude of the supercurrent and the electronic distribution function in the junction. This method for controlling the supercurrent has clear advantages over other known methods and is relevant for superconducting electronics applications. ©1998 American Institute of Physics.