Abstract: Method and apparatus for generating a current pulse of substantially constant amplitude and variable pulse width. A first energy source applied through a saturable device (e.g., a saturable reactor with a square loop operating characteristic) to an energy storage device (e.g., an inductor) maintains an initial energy storage level in the storage means and at the same time keeps the saturable device in a saturated condition. The application of a voltage pulse from a second power source to the energy storage device causes additional energy to accumulate in the storage device, which additional energy appears as an output current pulse in a connected load when the applied voltage pulse ends. The duration of the output pulse, which is essentially constant in amplitude, is controlled by the duration of the volatage pulse from the second power source.