| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To achieve downsizing, high efficiency and low noise switching power supply in which zero voltage switching of a switch is realized while reducing the size of a transformer. <P>SOLUTION: The switching power supply comprises a series circuit of the primary winding 5a of a transformer T and a main switch Q1 connected across a DC power supply Vdc1, a circuit for rectifying and smoothing a voltage being outputted to the secondary winding 5b when the Q1 is turned on, a series circuit of an auxiliary switch Q2 and a clamp capacitor C1 connected across the 5a, a series circuit of an auxiliary reactor Lx, a diode Dx1 and a snubber capacitor Cx connected across the 5a, a series circuit of a diode Dx2 and the Cx connected across the Q2, and a control circuit 10 for turning the Q1 and Q2 on/off alternately wherein the Cx is charged when the Q1 is turned on and gradient of voltage rise of the Q1 is relaxed by discharging the charges pf the Cx to the C1 when the Q1 is turned off. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
