Patent ID: 7142439

Claim:
A converter circuit, comprising: an AC-to-DC converter, comprising a plurality of first power devices; a resonant DC link, comprising only one power transistor and a first and a second DC link line; a DC-to-AC converter, comprising a plurality of second power devices; and DC link lines, coupling the AC-to-DC converter, the resonant link, and the DC-to-AC converter, wherein a first terminal of the power transistor is connected to the first DC link lines and a second terminal of the power transistor is connected to the second DC link line; and the resonant DC link is operable to clamp an operating voltage of the converter; wherein the power transistor of the DC link comprises: an auxiliary power transistor selected from the group of MOS-FETs and npn bipolar transistors; and an auxiliary power diode, coupled across the auxiliary power transistor; wherein the resonant DC link comprises: a first capacitor, coupled in series with the power transistor; a resonant capacitor, comprising parasitic capacitors of the power devices; an inductance, coupled in parallel with the power transistor and the first capacitor, the inductance forming a resonant circuit with the resonant capacitor; and a second capacitor, coupled in series with the resonant circuit.