Dear Aamir
Thanks for your help. i will design it on after two days and then i will contact to you but only tell me one thing what is the core size of ferrite core transformer used in UC3842 schematic . tell me the core which is easily available in markeet or can i use PC Power Supply Transforemr core.I study the application note and the winding of transformer is as below and also see attached picture:
Core:3C8 Ferrite EER3542D
1 →3: Primary Windings
50 turns AWG23 2 layers
5 →7: Auxiliary Winding
4 turns AWG37
10, 11, 12 → 8, 9: Output (+5V)
3 turns Copper Plate
8, 9 →13: Output(+12V)
7 turns 4 AWG35
(4 wires paralleled)
But you tell in your post that you have used 21AWG in primary. so please
1- tell me that how many turns and is it single layer wire or with 2 layer wire.i mean how many turns you wind with 21AWG and what is the layer configuration.
2- for secondary you have used 18AWG wire with 6 wires parallel. what is the turns ratio.7 turns or 8 turns. i have required 14.4 volt for battery charging.
3- tell me the winding procedure.which winding is start first, then second and then third and so forth either primary or secondary.tell me the steps of winding the transformer.4- what about auxiliary winding. is it same as mention in attached diagram or different.in diagram there is only 4 turns of AWG37 with single layer. is it ok or not.
5- what about 5 volt winding. leave it or wind it.
6- Can i use PC Power Supply Ferrite Core Bobin and core for this winding or not.
Please Aamir Bhai send me the complete procedure for winding the transformer bcz i m new with ferrite core transformer. if you have pictures of your wind transforme with steps then it is very helpful for me.your help will be very greatful for me.i m waiting from your reply.