Low-Cost Design of Auxiliary Power Supply for Urban Rail Transit Emergency Ventilation System

The auxiliary power supply requirements of urban rail transit emergency ventilation system are complex, and the traditional voltage regulator power module is large and high cost, so it needs a switching power supply solution with high efficiency, low cost and high power density. Based on UC3843 chip, a multi-output isolated switching power supply is designed. The principle of circuit topology is analyzed, and the high frequency transformer, starting circuit, clock oscillation circuit and feedback loop circuit are designed. Voltage and current double closed loop is used to adjust the output voltage, and has the function of overcurrent protection. After experimental debugging, the auxiliary power supply designed is small in volume, low in cost, stable in performance and meets the design requirements, and improves the power density and economic benefit of emergency ventilation equipment.