Patent ID: 8157718

Claim:
An electric circuit, comprising: a power supply unit; rectification means for rectifying current from the power supply unit; a transformer having an inductor on a primary side thereof connected to the power supply unit through the rectification means; a capacitor connected to an inductor on a secondary side of the transformer corresponding to the inductor on the primary side of the transformer, and operated so that, if power is supplied by the power supply unit through the primary side inductor of the transformer, the capacitor is supplied with the power from the secondary side of the transformer and stores charges at both ends thereof; reverse flow prevention means connected in series between the capacitor and the transformer to prevent charges stored in the capacitor from reversely flowing toward the transformer when the power is supplied; a discharge inductor for receiving the charges stored in the capacitor as discharge current and forming a magnetic field; first switching means for turning on or off flow of the discharge current that flows in one direction from the capacitor to the discharge inductor; and bypass means for causing current to flow in one direction from the discharge inductor to the capacitor, wherein the discharge current can cause L-C resonance between the discharge inductor and the capacitor through the first switching means and the bypass means, wherein, if the discharge current generates a magnetic field in the discharge inductor while causing L-C resonance, the power supply unit compensates the capacitor for power, lost due to the generation of the magnetic field, through the transformer, wherein the secondary side inductor of the transformer has a relatively higher inductance than that of the discharge inductor, and is used as power supply means during supply of power to the capacitor, and is used as a buffer inductor for attenuating current flowing through the secondary side of the transformer during L-C resonance, and wherein the rectification means prevents a reverse current that may flow from the primary side inductor of the transformer to the power supply unit during L-C resonance.