Control algorithms and circuit designs for optimally flyback-charging an energy-storage capacitor (e.g. for a flash lamp)

Optimum flyback-charging of an energy-storage capacitor is discussed. It charges the capacitor to a specified voltage within a specified time, with minimum peak current in the transistor and a transformer. Recommended methods are hysteretic current-mode control with current sensing in both transformer windings, peak-current-commanding current-mode control with switching frequency or transistor off time varying in a prescribed way during the charging, or valley-current-commanding current-mode control with switching frequency or transistor on time varying in a prescribed way during the charging.<>