Granted Patent B1

US 12,658,786 · App. 18/372,433 · Granted Jun 16, 2026

Inventors: Chimaobi Onyeachu (Greenbelt, MD); Nicholas Franconi (Greenbelt, MD)

Assignee: United States of America as represented by the Administrator of NASA

H02M1/36H02M3/3353

Abstract

Claims (14)

1 . A self-starting bi-modal operating isolated power converter comprising:

a voltage source;

one or more transistors;

a pulse width modulator;

a self oscillator circuit, comprising a first transformer, a capacitor, and a resistor;

wherein the pulse width modulator is connected to the self oscillator circuit in such a way as to be switched off until an under voltage lockout threshold is reached;

wherein the one or more transistors control a peak current through the first transformer and control self oscillation in a transition phase;

wherein the pulse width modulator is connected to the self oscillator circuit via a second transformer in such a way that upon reaching the under voltage lockout threshold, the pulse width modulator causes the isolated power converter to shift to operate in a fixed frequency mode, regulated by the pulse width modulator;

wherein the pulse width modulator controls the fixed frequency mode of the isolated power converter via galvanic isolation; and

wherein the peak current of the transition mode is set higher than the peak current in the fixed frequency mode to prevent interruption or instability while in the fixed frequency mode.

2 . The self-starting bi-modal operating isolated power converter of claim 1 , wherein each of the one or more transistors is a Gallium Nitride transistor.

3 . The self-starting bi-modal operating isolated power converter of claim 1 , wherein each of the one or more transistors has temperature-stable gate-to-source threshold voltage.

4 . The self-starting bi-modal operating isolated power converter of claim 1 , wherein each of the one or more transistors has a low gate charge.

5 . The self-starting bi-modal operating isolated power converter of claim 1 , wherein each of the one or more transistors has a high effective switching frequency.

Assignments (1)

References Cited (26)