Systems and methods for source switching and voltage generation

A system controller for regulating a power converter, the system controller comprising:

• a first controller terminal associated with a first controller voltage and coupled to a first transistor terminal of a first transistor, the first transistor further including a second transistor terminal and a third transistor terminal, the second transistor terminal being coupled to a primary winding of a power converter;
• a second controller terminal associated with a second controller voltage and coupled to the third transistor terminal;
• a third controller terminal associated with a third controller voltage and coupled to a first capacitor terminal of a capacitor, the capacitor including a second capacitor terminal;
• a first switch configured to receive a first signal and including a first switch terminal and a second switch transistor terminal, the first switch terminal being coupled to the second controller terminal;
• and
• a second switch configured to receive a second signal and including a third switch terminal and a fourth switch terminal, the third switch terminal being coupled to the first switch terminal, the fourth switch terminal being coupled to the third controller terminal;
• wherein the third controller terminal is configured to, in response to the second signal satisfying one or more conditions, charge the capacitor with a current flowing from the third transistor terminal to the first capacitor terminal through the second controller terminal, the second switch, and the third controller terminal.