A control circuit for controlling multiple power supplies having their outputs coupled in series is configured to in response to an output current reaching a defined current threshold of a power supply of the power supplies, control the power supply to operate in its constant current mode so that the output current is regulated at the defined current threshold as the remaining power supplies operate in their constant voltage mode, and in response to the output voltage of the power supply reaching a defined voltage threshold, control the power supply to operate in its constant voltage mode so that the power supply provides a first regulated output voltage to its output as the remaining power supplies provide a second regulated output voltage different than the first regulated output voltage to their output. Various other systems, power supplies, control circuit and methods are also disclosed.