• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

output transformer opposing windings/ please explain

Hi , So i recently finally repaired the output transformer of my Priboi , one of two was broken had one of it's two bobbins shorted between primary and secondary ,
so each of the two output transformers (one for each channel) has two bobbins on a common C shaped core , each bobbin has 3 layers of primary winding and two layers of secondary which are sandwitched between the 3 primary ones.

the fact that made me wonder is why one channel has the output transformer both coils wound the same direction while the other channel has both coils going the opposite direction to each other , like almoust the flux should cancel but it doesn't it works instead that way because when I first my accident wound it the same direction as the other channel and also the one which my logic told me it didn't work.
 

Attachments

  • c-core04.jpg
    c-core04.jpg
    108.4 KB · Views: 139

euro21

Member
Paid Member
2004-09-17 12:16 pm
Budapest
Do you know the Oersted's second "right hand rule"?

"The second right hand rule tells you the direction of the magnetic field due to an electromagnet. Wrap your fingers around the solenoid in the direction of positive current flow. Your thumb will point toward the north end of the induced magnetic field, as shown below."

Electromagnetism

Your c-core transformer "right" coil's magnetic field has "north" orientation (take right hand rule). If your hand wandering over the /double/ c-core, the "left" coil's magnetic field will be "south" orientation and current direction will be opposite as in "right" coil.