Patent ID: 7839092
Filing Date: 2010-11-23
Classification: H02M,H05B

Abstract:
1. A driving system having changeable output phase comprising a pulse-width modulation (PWM) unit to generate a duty cycle signal, a first driving unit and a second driving unit to receive the duty cycle signal, and a first transformer and a second transformer driven respectively by the first driving unit and the second driving unit to transform an input power to a first driving power and a second driving power to drive loads at a rear end, wherein: at least one of the first driving unit and the second driving unit is connected to a power phase control unit which generates a phase switching signal to modulate driving phase of the connected driving unit such that the first driving power and the second driving power have a same or different phase to drive the loads at the rear end; the power phase control unit is triggered by a trigger unit; and the power phase control unit connected to the driving unit includes a first comparator, a second comparator and a reference voltage source to provide a reference voltage, the first comparator having a first positive input end connecting to the reference voltage source and a first negative input end connecting to the trigger unit, the second comparator having a second negative input end connecting to the reference voltage source and a second positive input end connecting to the trigger unit, the phase switching signal being generated by comparing the reference voltage with the voltage of the trigger unit.