| 摘要 |
A switching power converter utilizing the single-ended converter topology and active clamp circuitry is described which dramatically reduces the input ripple current seen on the primary input circuit. As a result, a compact, virtually noise-free power converter is provided which further increases conversion efficiency and decreases EMI radiation noise. The power converter comprises two active clamp converters operating at substantially the same switching frequency and at an approximate phase angle difference of 180 degrees. Means are included to combine the input currents of each converter such that the effects of the secondary-circuit ripple currents cancel. As a further feature, means are included to combine the magnetizing currents of each converter such that the fluctuations in the magnetizing currents cancel. Input noise is further reduced by designing the converters to nominally operate at a 50 % duty-cycle at the targeted input voltage level. Owing to its compact size, high efficiency, and small input ripple current characteristics, the present invention is well suited for computer, telephone exchange, and telecommunications applications. |
