Winding your own Transformer?

[bandm1]

Hello everyone,

I am new here, so please bare with me.
I was drawn here by the Roll your own transformer article.
It was very informative and educational. I learned how to
calculate the primary and secondary windings for a power
transformer. But I would like to learn how to figure the same
for an Audio transformer. Does anyone know where I can aquire this information? :-\

Thank You All,

BandM

 

[MP1]

Bandm,
Welcome to the forum! Jan, the author of that article, has stated that he would be happy to help anyone if they need. Just send him an e-mail. I have not seen him on the list for a while.

MP

 

[Kevin Weddle]

I tried to build an autotransformer, but it turned out to be a high current inductor. It doesn't quite obey the 20db per decade law. The reason I could not make it an autotransformer is because the reactance wasn't high enough to connect it to the mains. I needed the thing to consume 20A peak with the load connected. But it blows the 20A peak fuse of the mains even unconnected. I am considering purchasing a 20A autotransformer, but they are expensive. To make the autotransformer, I used about 40AWG magnet wire that I bundled together so that it would handle the current. I wrapped this onto a transformer core. That magnet wire is difficult to solder to. Can anybody guess what guage of magnet wire is used in a 20A autotransformer?I don't know if they bundle smaller wire together or just use a big wire. It would have to be a large wire to handle 20A peak current.

 

[MP1]

Kevin,
You do not have to guess.

http://www.electronics-lab.com/articles/transformers/xformer3.htm

MP

 

[MP1]

Is anyone on this list building their own transformers? It seems that Jan is a little hard to find these days. Does anyone have some good sources for parts for building the transformers? I would like to find some good sources as I am now in a project that will require a specific transformer that I do not wish to purchase.

Thanks,
MP

 

[Kevin Weddle]

I did some experimenting and found that 22AWG wire will hande an average a little higher than 1A. This makes me think that a high current transformer uses one magnet wire of a higher guage. Has anybody had this experience with current in a wire? I know that the peak current can be higher than the rated average. But a fuse is just peak current.

 

[mitesh]

sir
i had winded a step down 5VA(220V/12V) transformer in my college lab. It was in a good working condition and had some little losses. But a little changes made by my friends lead to less losses in it.

 

[MP1]

mitesh, it would be good to hear about your experiences with winding transformers and the changes that your friends made. Have you seen the article on our website regarding this? It is here: http://www.electronics-lab.com/articles/transformers/index.html
Also, do you have some sources for the parts?

MP

 

[mitesh]

sir,
I have seen the address liked by u and downloaded all the pages.
I will tell u if there needs to change any article.But from the just first look does not suggest any changes.

 

[bandm1]

Hello Again All!

Since I left the original post I have found a plethora of information on winding your own transformers. The only thing I havn't found is a source for the Iron laminations for the cores and the Formvar coating
that is used to soak the transformer in when you are finished with the Xfmr. I can list the different sites I have found here if you all would like me to do so. It will just take a little time to put it all together.

Thanks All for responding to my post, BandM

 

[MP1]

Yes, please post as many sources as you have.
Thanks,

MP

 

[bandm1]

Hi All,

Here are some of the sources I found.
I have more, I just need to find where I saved them.


http://geek.scorpiorising.ca/windingtransformers.html

http://website.lineone.net/~dave.cushman/transformers.html

http://home.att.net/~chimeraone/vintagetransrebuild.html

http://www.ee.surrey.ac.uk/Workshop/advice/coils/power_loss.html#lams

http://www.geofex.com/Article_Folders/xformer_des/xformer.htm

BandM

 

[mitesh]

hello BandM
have u completed ur transformer and how is it working?