@ Upik
Hello Upic, about the capacitors 2.5uf X 400v (C4 snd C5) well you can put 2 in number capacitors of 1uf in parallel on each side so that you have 2uf and 2uf. These are to divide the voltage of the main bulk capacitor (C2 and C3) (680uf X2 in parallel) which are across the 320v dc bus.
Pad 9 is there so if you put earth screen (faraday screen) between primary and secondary. You may not use it if you want
The peak voltage with the number of turns is around 95v with 12.5 turns on secondary. If you want 80v peak there is different number of turns
SMPS is not regulated you can omit the output inductors L2 and L3.
New transformer turns for 80-0-80v peak is
Primary 18 turns so first half primary then two half secondaries then again half primary
Wire for primary and secondary enamel copper wire 0.5mm
Primary 2 bundles of 4wires each twisted together (total 8 wires )
start at pad 1 stop at 9 turns and put wire to side like in video then wind secondary and again 9 turns on top and stop at pad 2
Secondary 2 bundle of 4 wires each twisted (9 turns then center tap then start again from center tap and again another 9 turns)
(
1st half secondary) Start at pad 7 wind 9 turns finish at pad 6 (
2nd half secondary) start at pad 6 wind 9 turns and finish at pad 8
Other auxiliary windings can be put after you wind second half of primary (see video)
Link for video
https://www.youtube.com/watch?v=_K3ixhcTYFg
Please note that this video is NOT for this smps and turns are different but you can take a good idea how to do it
Regards Silvio