FERROXCUBE - TX36/23/15-3F3 - FERRITE CORE, TOROID, 3F3
14.7v, 30khz, 1600G, Ae .975 = 7.85 Pri turns.
Use 8 turns, 22awg, 10 strands.
10 strands on primary will fit, 11 strands will be tight.
Secondary 50vdc, 10vdc min voltage, 2 volts drop on bridge = 42 turns
Use 42 turns, 22awg, 2 strands.
2 strands on secondary will fit, 3 strands will not.
In the first TN example i do not think i had enough current capability for the primary. For that primary i took 300W / 14V = 21.4A
For this example i got a little more scientific.
300W / worst case voltage 10v = 30A
Next you have to increase the 30A to account for push pull efficency, my best guess is 70% worst case, and 90% best case.
8 pri strands is good for 30A, and a maximum of 10 strands will fit, so i would just go with 10 strands.