| 摘要 |
PURPOSE: An AC to DC converter is provided to achieve improved power factor and energy converting efficiency even without using a bridge rectifier circuit which causes high power losses. CONSTITUTION: An AC to DC converter comprises an AC input unit(30) for filtering the AC input applied from first and second input terminals, and outputting the filtered AC to first and second output terminals; a high frequency energy storing unit(36) including first and second inductors(L1,L2) connected in series to the first and second output terminals of the AC input unit so as to store the high frequency energy of the AC, a first switching transistor(Q1) which is repeatedly turned on/off operation when the phase of the AC is in a forward direction, and turned on when the phase of the AC is in a reverse direction, and a second switching transistor(Q2) which is turned on when the phase of the AC is in a forward direction, and repeatedly turned on/off when the phase of the AC is in a reverse direction; a high frequency switching current waveform sensing unit(32) including a first transformer(T1) and a second transformer(T2) for sensing the current flowing through the first and second inductors, and a third switching transistor(Q3) and a fourth switching transistor(Q4) which are turned on and off, respectively, when the phase of the AC is in a forward direction, and turned off and on, respectively, when the phase of the AC is in a reverse direction; and a high frequency output current smoothing unit(34) including a first rectifier circuit and a second rectifier circuit for rectifying the current output through the first and second transformers, and a capacitor(C1) for storing the energy output through the first and second rectifier circuits, smoothing the stored energy, and generating an output voltage. |
