Mahdi.sh
Newbie level 4
Hello everyone!
Im newbie with SMSP design. I have problems with my flyback SMPS.
Goal is to get 5V with 7Amps in output. At no load everything is OK and average voltage is 5V fixed, and also working good with 5ohm load. But unfortunately when I put a 1.5ohm (which means almost 3amps) average voltage decreases to 3V (and I see a lot of oscillation there).:-(
I use UC3843 as PWM controller , a EI28 ferrite core. Working frequency is 80KHz. I've attached the schematic.
My case is single output (just 5V 7A).
Actually Im suspicious of my transformer winding. How much is it important? I mean how much bad winding can effect on result??
Primary inductance : 300uH
N1/N2 = 5
Im newbie with SMSP design. I have problems with my flyback SMPS.
Goal is to get 5V with 7Amps in output. At no load everything is OK and average voltage is 5V fixed, and also working good with 5ohm load. But unfortunately when I put a 1.5ohm (which means almost 3amps) average voltage decreases to 3V (and I see a lot of oscillation there).:-(
I use UC3843 as PWM controller , a EI28 ferrite core. Working frequency is 80KHz. I've attached the schematic.
My case is single output (just 5V 7A).
Actually Im suspicious of my transformer winding. How much is it important? I mean how much bad winding can effect on result??
Primary inductance : 300uH
N1/N2 = 5