Stacked flyback transformer

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Junior Member level 3 My DCM flyback has specs:

Vin,min =21.6V
Pout,total = 11W
Vo1 = 3.3V (regulated) 1.98W
Vo2 = 20V 4W
Vo3 = 24V 4.8W
Vo4 = 7V 0.210W

I have calculated transformer primary and secondary windings as:

Np = 16
Ns1 = 2
Ns2 = 11
Ns3 = 13
Ns4 = 4

I am going to use stacked windings for first three outputs. So the stacked windings would be Ns1 = 2, Ns2 = 9 (2+9 = 11) and Ns3 = 2 (2+9+2 = 13). Now when calculating peak currents for stacked secondary windings, i am not sure is my calculations right? Pout, total = 11W gives me Ton = 2.18us and primary peak current Ip = 2.9196A ( Lm = 16.128uH ) and currents for stacked windings:

Is1 = Ip*$\frac{ Np}{Ns1 }$*$\frac{Po1+Po2+Po3 }{ Po,total}$ = 2.9196A*$\frac{ 16}{2 }$*$\frac{1.98W+4W+4.8W }{11W }$=22.89A
Is2 = Ip*$\frac{ Np}{Ns2 }$*$\frac{Po2+Po3 }{ Po,total}$ = 2.9196A*$\frac{ 16}{11 }$*$\frac{4W+4.8W }{11W }$=3.397A
Is3= Ip*$\frac{ Np}{Ns3 }$*$\frac{Po3 }{ Po,total}$ = 2.9196A*$\frac{ 16}{13 }$*$\frac{4.8W }{11W }$=1.568A

goldsmith Hi
Goldsmith

grizedale also worth remebering that even of you do stacked windings, its still best to give each secondary "section" its own full layer....this improves cross regulation further.

Junior Member level 3 Goldsmith, Switching frequency is fs = 200kHz

goldsmith 