| 摘要 |
In order to reduce switching losses, the frequency of a switched-mode power supply is lowered, in the instance of a diminishing output load, by frequency changes which can, however, cause disturbances, e.g. a corruption of the image geometry in television receivers. The disturbances caused by frequency changes can be reduced by adjusting the characteristic of the control system which is, however, relatively complex. A simple, very inexpensive and yet extremely effective solution for reducing disturbances caused by frequency changes provides that, in the case of a switched-mode power supply, the beginning of the process of lowering the frequency to lower power outputs is postponed so that the frequency changes occur in a power range where they no longer create disturbances. The invention is suited for switched-mode power supplies having a primary current simulation, e.g. for the Siemens Module TDA 16846. Corruptions of the image geometry no longer occur in a television receiver when using the inventive switched-power mode supply.
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