| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching power unit which can reduce noise and improve efficiency and suppress rise in cost. SOLUTION: A series circuit, composed of first and second switches Q1 and Q2, is connected between a pair of DC output lines 9a and 9b of an input rectifying and smoothing circuit 4. Capacitors C1 and C2 are connected in parallel with the first and second switches Q1 and Q2. A series circuit composed of a primary winding N1 of a transformer 1 and a capacitor Cr for current resonance is connected in parallel with the second switch Q2. An output rectifying and smoothing circuit 5 is connected to a secondary winding N2. The first and second switches Q1 and Q2 are alternately turned on and off, having deafened time. The primary winding N1 and the secondary winding N2 of the transformer T are arranged in different positions of the core 10 to reduce the floating capacity between each other. Moreover, the core 10 is connected to the cold end.
|
