A power supply circuit, comprising a first reverse blocking transistor
coupled to an AC power line; a second reverse blocking transistor coupled
to the AC power line; a first inductor provided between the first reverse
blocking transistor and the AC power line and configured to store energy;
a first diode having a first terminal that is coupled to one end of the
first inductor; a first capacitor having a terminal that is coupled to a
second terminal of the first diode; and a first output terminal provided
between the first diode and the first capacitor. The first and second
transistors are arranged in an anti-parallel configuration and together
define an AC switch.