T
treez
Guest
Hi,
A contractor has given us a transformer manufacture spec for a 120W Offline Flyback.
For the secondary, he has 11 turns of 3 strands of TEX-FS 0.7mm triple insulated wire.
This 11 turn secondary has a total width of 29.7mm, when the bobbin width is only 27.7mm.
Would you presume that this means he has wound ten turns and then the eleventh turn is spiral wound evenly back round and across the bobbin to be terminated?
This method of spiralling the final turn back and then terminating it, sounds like a great idea....why is it not done as a standard technique? After all, with offline SMPS transformers, one usually terminates all primary side windings to the same side of the bobbin (for isolation reasons)...which means having to bring the coil_end back across the bobbin.....if you've gotta do that, then why not spiral the final turn back as described. Why is this technique not standard?
(The bobbin is a 12 pin E42/21/15)
E42/21/15 former
Tex FS 0.7mm triple insulated wire:
www.pacecomponents.co.uk
A contractor has given us a transformer manufacture spec for a 120W Offline Flyback.
For the secondary, he has 11 turns of 3 strands of TEX-FS 0.7mm triple insulated wire.
This 11 turn secondary has a total width of 29.7mm, when the bobbin width is only 27.7mm.
Would you presume that this means he has wound ten turns and then the eleventh turn is spiral wound evenly back round and across the bobbin to be terminated?
This method of spiralling the final turn back and then terminating it, sounds like a great idea....why is it not done as a standard technique? After all, with offline SMPS transformers, one usually terminates all primary side windings to the same side of the bobbin (for isolation reasons)...which means having to bring the coil_end back across the bobbin.....if you've gotta do that, then why not spiral the final turn back as described. Why is this technique not standard?
(The bobbin is a 12 pin E42/21/15)
E42/21/15 former
Tex FS 0.7mm triple insulated wire: