摘要 |
In order to achieve complete short-circuit protection irrespective of a location of a short-circuit in a switched-mode power supply having a controllable switch in a primary circuit, the controllable switch is opened when a voltage drop across an electrolytic capacitor in a primary circuit falls below a threshold value which can be predetermined. For this purpose, a capacitive voltage device containing two capacitances is connected in parallel with the electrolytic capacitor. A potential at a center tap of the capacitive voltage divider is compared in a comparator with a reference voltage, which opens the controllable switch when the potential at the center tap falls below the reference voltage.
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