Winding transformer

I need a transformer for an audio amp, cant find a replacement for less than $120. Transformer has a couple of windings on the secondary. 32vac each side of the center tap, 18volts ac for the preamp stage and 6 volts for lights. I Have a couple of old VARIACs that the mechanical parts are bad/missing. I was thinking of using one of these as the primary for the transformer and hand winding the secondary. I am figuring about .6volts a turn. Any reason why these would not work.

Reply to
Jimmie
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What is your tolerance?

Reply to
Brian

I don't think that's a very graceful way to achieve what you want to be honest. Why not use a large, more readily available 32-0-32 transformer for the power amp, and a seperate transformer(s) for the preamp and lights? The latter transformer(s) shouldn't need to be very big and you should be able to find space in all but the most packed amps.

Dave.

Reply to
Dave D

comes down to.. if the jobs worth doing...... $120 isnt a lot, depending on the current draw of the system...

Paul Miller iEng MIIE (elec)

Reply to
Paul Miller

in article snipped-for-privacy@ersa.uk.clara.net, Paul Miller at snipped-for-privacy@DROPpaulmiller.co.uk wrote on 2/12/05 9:49 PM:

It can really be expensive to make a few units.

At one time, probably at least an inflation factor of 10 ago, I was working for a place that was buying flashtube trigger transformers from EG&G for about $130 each. It really was a simple but low volume transformer. I designed one that worked just fine for about what I now estimate is about $30. Once we went into production for internal use, we saved a fortune. Moreover, long delivery time were under our own control.

That said, audio transformers can be much more complicated if you have to consider leakage inductance, saturation etc. Don't forget that cores for 60 Hz may behave poorly at 10 kHz.

Bill

Reply to
Repeating Rifle

Well just went ahead and did it, It seems to work fine. Think I will take that $120 I saved and take my wife out to dinner.

Reply to
Jimmie

An advantage to a toroid transformer is its much lower 60 cycle magnetic radiation. Some high quality audio amps use them only for this reason. You were saved the trouble of winding the primary turns!

Reply to
VWWall

Not to mention finding a torodial core.

I had two identical amps, That how I knew the voltage of the transformer. Funny thing ,since I changed the transformer the amp sounds better. I cant quite describe how. Think it may be because I didnt really have the right wire for the current rating of the amp so I used some 12 guage enameled wire I had around. This was a lot bigger than what was in the old transformer.Think I am going to do this to the other amp now.

Reply to
Jimmie

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