Salvaging Transformers

[kneadle]

Hi all,

There was a thread somewhere on this forum about salvaging transformers, but I can't find it.

I took apart my Pioneer VSX-402 (and it was a sad thing, too college memories), hoping to re-use some of it. Problem is, all the stuff is integrated, but among a few things, the transformer seems to be salvageable.

I just don't know much about it, and I don't know where to find info for it, and not just the rating, but HOW to salvage it and use it again.

Thanks,
Dave

[kneadle]

And another pic.

[Stocker]

If you still have the rest of it, you will have better luck. If you can spot where the secondaries connected to the rectifiers you will know where to measure from. If not, you can slap a voltmeter on all the secondaries relative to each other. If some of the outputs don't make sense, you know they probably aren't a proper secondary voltage. Another way is to see with an ohmmeter if the secondaries are all one wire or are they separate windings...

[Evan Shultz]

once you have the Tx identified as Stocker suggests, remove the solder and pull the Tx off the board. make sure the keep the parameters with the Tx so you can keep track of it. The bridge from the second pic might also be worth taking.

There's no trick to reusing a Tx, if it has suitable secondary voltages, then put it in there. Since you may not know the VA or current limits [can we assume they are low since this is a commerical product?], I know of no sure way to determine the maximum rated current. Good luck!

[tg3]

What was the power rating on the back of the amp chassis? This will give you some idea of the VA rating of the transformer.

[kneadle]

Originally posted by Evan Shultz
once you have the Tx identified as Stocker suggests, remove the solder and pull the Tx off the board. make sure the keep the parameters with the Tx so you can keep track of it. The bridge from the second pic might also be worth taking.

There's no trick to reusing a Tx, if it has suitable secondary voltages, then put it in there. Since you may not know the VA or current limits [can we assume they are low since this is a commerical product?], I know of no sure way to determine the maximum rated current. Good luck!

This is what I was afraid of. There was no "rest of it." When I said "integrated," I wasn't kidding; the board pictured was soldered directly to the housing of the transformer, as though the two were manufactured only for each other. No gangly wires were there or anything. It seems the primaries and secondaries are accessed through that board.

Power rating: 230 watts. I'll do some googling now.

Oh well, I need a nice 20 pound dumbell for exercise.

Thanks,
Dave

[Stocker]

Come on now, don't give up so easily!

Measure the secondaries and find out what's what. Solder some wires to the primaries to get them to a mains socket and see what the secondaries give you. Then divide that voltage by 230 for your favorite secondary voltage, and you will have a (probably optimistic) voltage and current rating.

It's easy.

[mcs]

Originally posted by Stocker
Solder some wires to the primaries to get them to a mains socket and see what the secondaries give you.

Don't forget a fuse!

I would probably just connect 12V AC to the primary for more safe measuring...

Best regards,

Mikkel C. Simonsen

[Stocker]

Actually, in the first typing I had both a fuse and a GFCI socket. In my own testing I used very fine wire to go to a GFCI power strip. Either way, if the unit was not non-functional because of the power section, the transformer should need nither.

You know, if you just want it to be used and don't care to work at it, you could always ship it to me...

...for the cause, of course!

[kneadle]

How do I determine where the mains and secondaries are if there are no wires to play with?

Dave