A system and a method for to use multiple power sources for supplying
power to a load. The system and method use a triggering system to
automatically and substantially cancel a ripple component of the input
current drawn by the system. A master power source and a slave power
source supply power to the load. The triggering system results in the two
power sources having switching frequencies that are substantially equal
and switching cycles that are substantially 180.degree. out of phase.
Further, the method and the device contemplate the use of a local
oscillator in the triggering system to ensure that the slave power source
is triggered to the on position at a point in the switching cycle of the
master power source that is approximately 180.degree. out of phase with a
leading edge of the master switching drive signal. The system and method
are advantageously used to provide a power factor correction front-end
for a switch-mode power supply. Power supplies with a diverse array of
relationships between power supplied and switching frequency can be used.