Circuit arrangement for limiting the switch-on current and for providing an over voltage protection in switch mode power supply devices

摘要

Circuit arrangement for limiting the switch-on current and for overvoltage protection of switched power supply apparatuses having an input-side storage capacitor (12), which forms a low-impedance voltage source for a power supply arrangement connected thereto. Such a power supply apparatus is intended to be provided with a circuit which not only limits the switch-on current but also ensures protection against overvoltages on the storage capacitor (12). This is achieved with the aid of a field-effect transistor (11) arranged between the supply voltage source (1) and the storage capacitor (12), which is not only controlled by an amplifier in the sense of current limiting but is also controlled by a delay member in the sense of delayed switching on. The power supply apparatus is particularly suitable for plug-in assemblies with voltage converters for supplying electrical telecommunications devices. …IMAGE…