Comments Please: Winding own audio power transformers

[UncleJessie]

Well, I've got a couple of diy projects ready to go but am holding off because I don't really want to drop $200 - $400 on each power transformer. If I can't scavenge some used ones, I'd like to try to build 'em myself.

Has anyone out there ever built their own power xformers? I'd like to get your feedback: the good & the bad, level of expectation, tips/references so that I can build my own, etc.

Any help will be appreciated. Thanks.

-UJ

 

[bmcevers]

If you are planning on building a solid state amp you might want to check out the AVEL Toroidal transformers at partsexpress.com
An 800 VA model with several secondary voltages to choose from for about $70.

Good Luck!!

 

[Jocko Homo]

I assume that you are talking about a stacked lamination type. DIYing your own toroids is harder.

Jocko

 

[SY]

Jocko, how so? (Asks the guy who's never wound one)

 

[Jocko Homo]

How so to which one?? The techniques used for each are different. About the only thing in common is what size wire.....and the rule of thumb is 700 circular mils/amp. I need more info on what he is trying,and where he is at, to give specific advice.

Jocko

 

[SY]

No, I was just curious why a toroid would be harder to wind. Is it because you can interleave the EI laminations into a bobbin after doing the winding?

 

[TonyTecson]

finding the core material for a torroid is one, then winding the coils is much harder for a torroid as you have to get you magnet wire around to core to start winding them, but winding torroids is more fun although difficult....

 

[Jocko Homo]

You have to make sure that the windings are evenly distributed across the core. The machines that wind them have software that calculates the pitch of the windings. Hard to do by trial and error.

Jocko

 

[SY]

Thanks, Jocko. Why is the pitch more critical for a toroidal core (assuming you're just using it for 50/60 Hz service)? Is it a specific critical value that depends on wire size, core geometry, or whatever, or is it a matter of just having the pitch be even throughout the windings?

Sorry for the dumb questions- this is an area where my experience is zero. And I've seen some wind-it-yerself toroid kits and wondered if I should do it...

 

[Jocko Homo]

Toroids aren't supposed to radiate right? Wrong, they do.......some. An unbalance in the winding distribution will make it worse. One guy who winds them for me says that it can make them hum a little more if you do. Never tried it, so I can not verify that he is not being a wise guy like we tend to be (sometimes).

Toroids of course hum if there is any DC on the line. But it is also dependent on how tight the tape that makes up the core is wound. Something that no one who makes them has much control over. So.....they take all steps possible to make sure that they don't make them worse. Or else wise guys like us who buy them will complain.

More than we usually do.

Jocko


Jocko

 

[TonyTecson]

winding coils for a torroid, the wires at the inner circle will be close and adjacent to each other but at the outer perimeter there will be a separation between adjacent turns, this is the pitch...