Research On A Power With 20A(5～48V) Output Based On PS ZVS-PWM-DC/DC Full Bridge Converter

A phase-shifted controlling PWM DC/DC full bridge converter with softswitching is proposed and used to realize a constant current power of20A(5～48V).This full bridge converter utilizes the transformer leakageinductance(or the resonant inductance in series with transformersprimary)and the autoecious capacitance of MOSFET to achieveZVS(Zero-Voltage-Switching) ,as a result it can decrease the switchingwaste,increase the switching frequency,and diminish the power bulk.Inthis paper,the former 6 operated courses of the full bridge topology aredetailed and the design principle of some main parameters is gained.Incontrolling circuit,the power uses voltage feedback loop and currentfeedback loop.In order to get constant current output,the voltagefeedback loop tails after current feedback loop to maintain the loopstabilization. UC3875 is used as controlling IC , IRFP460 is used as powerMOSFET and the switching frequency is 100KHz that avoid the boringyawp.The power input SP(single phase) 220V/50Hz AC and get 20A/(5-48V)DC output.Parameters design of the power are calculated,the operation ofthe controlling circuits,the protecting circuits and the auxiliary powersupply circuits are analyzed also.In addition,The experimental resultsare included in this paper.The efficiency of the power can even achieve92%.