Patent ID: 8760897
Filing Date: 2014-06-24
Classification: H02M

Abstract:
1. A DC-AC converter, comprising: a time-varying DC power generating circuit, controlled by a pulse width modulation (PWM) signal to transform a DC source to a time-varying DC power; an AC power generating circuit, receiving the time-varying DC power and being controlled by a first polarity switching signal and a second polarity switching signal to generate an AC power; and a transmission capacitor, coupled to the time-varying DC power generating circuit and the AC power generating circuit, for transmitting the time-varying DC power from the time-varying DC power generating circuit to the AC power generating circuit; wherein the time-varying DC power generating circuit comprises: an inductor, having one terminal coupled to the DC source and one other terminal coupled to an input of the transmission capacitor; a PWM switch, coupled to the one other terminal of the inductor and the input of the transmission capacitor; and a first rectifying element, having a first terminal coupled to an output of the transmission capacitor and a second terminal coupled to the PWM switch; and the AC power generating circuit comprises: a second rectifying element, having a second terminal coupled to the output of the transmission capacitor; a first polarity switch, coupled to a first terminal of the second rectifying element; a second polarity switch, coupled to the first terminal of the second rectifying Element; a third rectifying element, having a second terminal coupled to a load; and a fourth rectifying element, having a first terminal coupled to the load; a transformer is coupled to the first polarity switch, the second polarity switch, the load, a second terminal of the fourth rectifying element and a first terminal of the third rectifying element.