| 摘要 |
The switched-mode power supply has a storage capacitor, a transformer with a primary winding and at least one secondary winding, and also a switching transistor which is connected in series with the primary winding. The primary winding is subdivided here into sub-windings with at least one tap, and a capacitance is in each case disposed in parallel with sub-windings, preferably with each sub-winding, as a damping network. The numbers of windings of the sub-windings and the capacitances of the capacitors disposed in parallel with the sub-windings are selected in such a way that the oscillations occurring when the switching transistor is deactivated have different resonant frequencies and thereby partially cancel each other out. This results in an effective damping of the deactivation voltage over the switching transistor. Since the capacitors are connected in series, the effective total capacitance is low, so that the resulting discharge current at the activation time of the switching transistor is comparably low.
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