SWITCHING MODE POWER SUPPLY HAVING FUNCTION OF SOFT START AND OVER LOAD PROTECTION

摘要

PURPOSE: A switching mode power supply having soft star and overload protection functions is provided to implement the soft start and the overload protection performance at the same time by including a dividing circuit inside the switching control unit without using an external capacitor for delaying. CONSTITUTION: A transformer(100) comprises a primary coil(L1) and a secondary coil(L2) supplied with the DC power. The secondary coil is transferred with the energy from the primary coil and outputs it. A switching control unit(200) controls the main switch connected to the primary coil of the transformer in the PWM(Pulse Width Modulation) manner.