I am using ST's eDesign Suite for designing power supply. (AC-DC Converter)
I contacted the transformer design firm to get my transformer designed. I gave them all the information regarding the number of turns and length of wire etc..
Here is my power supply specs
Input: 95 Vac - 265 Vac - 50 Hz - Operating Vdc [96.9 V - 374.8 V]
Output Power: 14.96 W
Output -: 17 Vdc (38 mVpp ripple) - 880 mA max - 14.96 W - Regulated
Switching Frequency (fsw): 60 kHz
Transformer Specs :-
- fsw: 60 kHz
- Prim/Aux turn ratio 6.39
- Prim/Out 1 turn ratio 4.77. (Np/Ns)
Design Specs :-
- Type EE20/10/6 (EF20) TH-V 10-Pin
- Core Gap: 0.28 mm expected
Primary: Turns 105 - Layers 6 - Paralleled wires 3
Secondary: Turns 22 - Layers 3 - Paralleled wires 3
Auxiliary: Turns 16
Power Supply Layout :- Attached
Now I need to order the design for transformer and the transformer design centre asking for dot polarity/Start-End point of pins. According to circuit, there are only 4 pins used on AC side and 2 pins on DC Side. The ST recommends EE-10 size Bobbin.
Wurth Electronics Transformer Winding Layout :- Attached
Do I need to use Pin 2 for interleaving/CenterTapping, though in schematic it is not mentioned, but only in transformer layout. Or should I go with simple 3 windings (without Center Tape) as mentioned in schematic i.e For Primary (Pin 1 -> Pin3),
For Aux (Pin 4 -> 5),
For Secondary(Pin 7 & Pin 8 -> Pin 9 & Pin 10).
I only need 6 pin for my circuit, but the layout for Transformer shows 10 Pins. I am confused about the it.