Amp transformer wirring

[edzy 10+ year member]

So, I unwound my transformer, but now i dont know how the terminals were connected.

Im thinking

1 to 2

3 to 4

5 to 6

7 to 8.

Yes ? no?

Click to read more...

 

[thch 10+ year member]

not sure what you're calling 1/2/3/4. clearly two windings will be thicker and two will be thinner.

from there, i'd hope you know the way you re-wound the transformer, and have some idea of how to reconnect it. It might help to use a DMM to see which pads connect to things like +12V, or each other. I'm guessing two connect to 12V and the other two connect to tabs on the transistors on the bottom. use the black lead for the transistor tabs.

I'm guessing there's a part i'm not seeing. in anycase, the other pads probably connect to the large dual-pack diode in the upper left corner, as well as whatever point can be used for "ground". possibly connected to the RCA cabled via some resistor, or maybe one of the speaker terminals.

all of that assumes a single output push-pull.

the lack of dots on the transformer diagram might indicate there is a 50/50 chance this will end badly. the coloring of the wires seems a bit off as well. Have you also changed the windings on the transformer?

 

[Grinder1989 5,000+ posts]

Why would you unwind it?

 

[gunz4me 10+ year member]

I wished him luck in rewinding it in his original thread. Sadly you really NEED to know what you are doing to rewind a transformer!

 

[edzy 10+ year member]

What I am saying is,

There were 4 wires.

Say wire one started at terminal 1, wound around the coil and ended at terminal 2

like in this pic, The red wire is in terminal 7 it conects to either 5, 6, or 8.

Im guessing 8.

I unwound it because I didnt like the look of it.

I thought it would be fun.

I have free time and money to spend on new magnet wire.

Just something to do.

Thanks for the info.

 

[thch 10+ year member]

just out of curiosity, is the above picture of a broken amplifier you attempted to fix, or of an amplifier that was damaged during this testing?

in anycase, the best thing to do is see to determine which wire would connect to which locations. the polarity of the windings somewhat matters as the idea is to essentially magnetize the transformer then switch polarity and magnetize it in that polarity, then switch. this prevents you from over-magnetizing the core. the very rapid rate is what allows the transformer to be so small. If you have both windings connected with the same polarity, then you over-magnetize (saturate) the transformer and take turns blowing up parts.

likewise, windings in some locations aren't dangerous, but just don't work. I could guess which ones go where, but its much safer to confirm things are done correctly before you do them.

 

[edzy 10+ year member]

""just out of curiosity, is the above picture of a broken amplifier you attempted to fix, or of an amplifier that was damaged during this testing?""

Yes, It is the same amp.

It was damaged, So I replaced the fets.

Then the coil looked bad, So I unwound it to check for shorts.

I have the new magnet wire, but am forgetting how it was connected.

After the coil is repaired, I will probly find something else wrong.

Ive all ready spent more on this trying to repair it then its worth. But its not a money issue. Just like to try and do it myself.

""but its much safer to confirm things are done correctly before you do them.""

Hence this thread.

 

[edzy 10+ year member]

so.....

 

[thch 10+ year member]

To make a good decision, i'll need the info from posts 2 and 6. post 2's questions relate to mapping what coils go where, and post 6's relate to ensuring the transformer was re-wound correctly.