A power supply of one embodiment of the invention is disclosed that includes a
conversion mechanism and a feedback mechanism. The conversion mechanism is to control
conversion of a first direct current (DC) signal from to a second DC signal provided
to an electronic device by switching the first DC signal to vary the second DC
signal. The feedback mechanism is to cause the switching control mechanism to operate
in a nominal-power mode or a reduced-power mode according to a control signal received
from the electronic device. The conversion mechanism is caused in the reduced-power
mode to lessen at least one of the duty cycle and the frequency at which the first
DC signal is switched until the voltage of the second DC signal decays to a first
voltage level.