Control principle for a switched-mode power supply

摘要

The subject-matter of the invention is a control principle for a switched-mode power supply for complete load control. In this case, the control circuit operates using the combination of the two control principles of pulse-width control and multi-cycle control. In the region of normal load operation tw, the control circuit operates on the principle of pulse-width control, while, in the event of the loading being reduced below the minimum load temin for pulse-width control, it changes over in the region tp to the control principle of multi-cycle control tp. In this way, the output voltage UA can be controlled in a stable manner down to no load. <IMAGE>