Inventors:
Nathan O. Sokal - Lexington MA
International Classification:
H02M 3335
Abstract:
A flyback charger for an energy-storage capacitor has a controller for causing the energy-storage pulses of current in the transformer primary winding and the energy-delivery pulses of current in the transformer secondary winding to be nearly flat-topped. The controller includes a peak-current-commanding current-mode control or a valley-current-commanding current-mode control which controls the duration of a switching circuit on and off interval, respectively, responsive to the current flowing in the transformer primary winding and secondary winding, respectively. A feed-forward controller controls the duration of the switching circuit off and on interval, respectively, in response to the voltage provided by the secondary winding and D-C supply voltage, respectively. When using the valley-current-commanding current-mode controller, there may be a fixed duration of the switching circuit on interval.