The paper introduces the principle of switch power which is composed by current control type PMW UC3842 and analyzes the shortage of protective circuit and proposes an improving idea.
The third chapter mainly introduces the hardware design of soft starter, including the main circuit, control circuit, drive circuit, and protect circuit and auxiliary switched power design.
Single-chip switching power supply are produced especially for switching power supply, which integrate PWM and high voltage MOSFET together , and have perfect protection function.