Switched mode power supply (SMPS) e.g. for television equipment, decoders, LCD projectors etc

摘要

The switched mode power supply includes a switching transistor (Tpr) at a primary side, and a transformer (TR) with a secondary winding (Ws) for the production of a secondary output voltage (DC). A switch (T1) and a current measurement element (CST) are arranged in the current path of the secondary winding. The switched power supply includes a control circuit (T2, T3, T4) which uses a signal from the current measurement element for the control of the switch, to provide a rectification of the secondary output voltage. The transformer includes preferably an auxiliary winding (W3) at its secondary side, which serves for an additional synchronization of the switch with the switching frequency of the switched power supply.