Transformer winding sequence
Transformer calculations
frequency 60Khz B= 1400 guass input voltage 230v AC transformer ETD49
copper wire 0.5mm
Primary 22 turns Secondary 7 turns (7.2v per turn)
Peak output voltage 50.9 volts each rail at 230 volts
Output capacitance 4000 uf per rail (4 X 1000uf)
output inductor 1.5 uH per rail ( 5.5 turns enameled copper wire 1.5mm dia on 10mm ferrite rod 30mm long)
Maximum current at output 12A @ 84volts = 1000W
Copper wire primary:---5 wires 0.5mm twisted together (2.8 meters long) approx
copper wire secondary:---8 wires 0.5mm (2 bundles 4wires twisted together ) (3.5mts long) approx
Margin tape = 5mm on each side for primary and secondary
Winding sequence
make 5mm wide margin tape on each side of bobbin (about 2mm high)
1/2 primary 11 turns ( leave the extra wire on the side to wind the second half with it)
3 layers of Mylar tape (cover the whole width of the bobbin with tape)
Make 5mm margin tape on each side of bobbin
1/2 secondary 7 turns ( start from center tap and leave around 100mm of wire outside bobbin) put 2 bundles of 4 twisted wires side by side and wind together.
2 layers of mylar tape
make 5mm margin
1/2 secondary 7 turns ( same as above)
3 layers of mylar tape to cover whole width of bobbin
make 5mm margin tape
Half Primary Take the rest of the wire of the primary and wind the rest of the 11 turns.
3 layers of mylar tape
Auxiliary windings
calculate at 7volts per turn so for 21volts = 3turns and for 14volts = 2 turns,
If you want a double winding then put 2 wires 0.5mm together and start from center tap and wind the turns needed then put the ends on each pin.
3 layers of Mylar tape
IMPORTANT Please follow the instructions carefully and use suitable tapes suggested for a safe transformer
You have to put sleeving at the ends of each wire.
Take a look at the video on youtube and follow the instructions there The video is called winding small transformers for smps (By Silvio) you will take good advice how to wind a good transformer.
Regards Silvio