Patent attributes
A driving system with a changeable output phase includes a PWM unit to generate a duty cycle signal, a first driving unit, a second driving unit, a first transformer and a second transformer. The first driving unit and the second driving unit receive an input power and the duty cycle signal to drive respectively the first transformer and the second transformer to transform the input power to a first driving power and a second driving power. 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 the driving phase of the connecting driving unit so that the first driving power and the second driving power output from the first and second transformers have a same or different phase to drive loads at the rear end.