Author Topic: Easiest way to rewind transformer  (Read 461 times)

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Offline 001

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Easiest way to rewind transformer
« on: October 12, 2019, 08:18:10 pm »
Hi

is it possible rewind transformer without winding machine?
 

Offline LateLesley

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Re: Easiest way to rewind transformer
« Reply #1 on: October 12, 2019, 08:39:57 pm »
I think it is, but you would need a lot of time and patience. You could probably make some form of jig to do it. There's plenty of videos on youtube on how to wind transformers. Here's one example.



You'd probably be better trying to find one ready made to fit your needs though.
 

Offline wraper

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Re: Easiest way to rewind transformer
« Reply #2 on: October 12, 2019, 09:01:16 pm »
Completely possible. Though will require patience and winding quality will be worse unless you want to spend a lot of time to do it neat.
 

Offline TheMG

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Re: Easiest way to rewind transformer
« Reply #3 on: October 12, 2019, 11:06:54 pm »
Toroidal transformer, or E-I core transformer?

Toroidal transformer is totally doable, but without a specialized machine will require A LOT of patience as the the entire length of the winding needs to be passed through the core of the toroid every single turn.

E-I core can be much easier IF the core can be disassembled so you can remove the bobin from the core. Some transformers the laminations are welded together, but others are held by a crimped outer shell or even nuts and bolts. Almost all are dipped in varnish which will tends to stick the laminations together.

So yes, totally doable, but depending on the specific construction of the transformer can range from a fairly easy task to a complete nightmare.

If you can free the bobin from the  core, you can rig something up to a variable speed drill to accelerate the winding process.
« Last Edit: October 12, 2019, 11:08:54 pm by TheMG »
 

Offline 001

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Re: Easiest way to rewind transformer
« Reply #4 on: October 13, 2019, 08:37:51 am »
Yea

I mean EI cores

But I can`t google practic guidelines exept manuals for semiautomatic monsters
All I have is hand drill jig and hands
It is low end technology
How to make winding outputs right? How to make bobbin from paper? What is the best way to glue? etc

 

Offline PKTKS

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Re: Easiest way to rewind transformer
« Reply #5 on: October 13, 2019, 02:36:36 pm »
the thicker the gauge  the more impractical it is.

Although some thin coils can be done ... more or less easily

A small machine does worth the money

Paul
 
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Online bd139

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Re: Easiest way to rewind transformer
« Reply #6 on: October 13, 2019, 03:05:21 pm »
My uncle has a winding machine he made himself. It was a drill mount on a bit of plywood, a bit of threaded rod and a couple of chunks of plywood and some wing nuts and washers to clamp the bobbin. He made a turns counter with a microswitch screwed to the base activated with an egg shaped bit of plywood. This was all attached to a simple 4 banger calculator’s equals button. You put 1++ in the calculator and start winding and it accumulates the turns. Must have cost him about $10 in parts.

I occasionally wind E cores here. Usually just do it by hand. Takes a while but not impossible.
« Last Edit: October 13, 2019, 03:06:56 pm by bd139 »
 
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Offline exe

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Re: Easiest way to rewind transformer
« Reply #7 on: October 13, 2019, 07:31:47 pm »
the entire length of the winding needs to be passed through the core of the toroid every single turn.

I think it's possible to do several windings and connect them in series. Or just make one winding from multiple pieces of wire. Just be sure to insulate it well, and no sharp edges so it won't damage other turns.

PS I also compared tight turns with loose ones. No difference in output voltage, even if it's super-loose. But I recommend to make it tight a bit to reduce hum and friction between turns. Friction may damage insulation and cause shorts.
« Last Edit: October 13, 2019, 07:33:36 pm by exe »
 

Offline wraper

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Re: Easiest way to rewind transformer
« Reply #8 on: October 13, 2019, 09:24:19 pm »
the entire length of the winding needs to be passed through the core of the toroid every single turn.

I think it's possible to do several windings and connect them in series. Or just make one winding from multiple pieces of wire. Just be sure to insulate it well, and no sharp edges so it won't damage other turns.
You don't need to do such stupid shit. Just use netting shuttle with enough wire for entire winding.
Quote
PS I also compared tight turns with loose ones. No difference in output voltage, even if it's super-loose.
Of course there won't be difference under no load. However total winding length will be longer = higher resistance. Also you use more space, thus will need to use thinner wire than you could. Again meaning higher resistance.





« Last Edit: October 13, 2019, 09:34:45 pm by wraper »
 
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Offline Bud

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Re: Easiest way to rewind transformer
« Reply #9 on: October 13, 2019, 09:50:00 pm »
I used to do something like in your first photo, with a proper ratio of the transformer circumference to the jig length you can do just fine in terms of convenience and easy of the winding job.
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Offline jdragoset

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Re: Easiest way to rewind transformer
« Reply #10 on: October 14, 2019, 12:20:11 am »
For smaller ID toroids, I use a pop sickle stick cut with a "V" notch each end as the net needles will be too wide.
As a group, the automatic toroid winding machines and operators were exceptional pieces-of-work.
Very many, reliably, have gone into orbit and beyond.
 

Offline tautech

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Re: Easiest way to rewind transformer
« Reply #11 on: October 14, 2019, 04:25:40 am »
Hi

is it possible rewind transformer without winding machine?
Yep, lathe or cordless drill on slow speeds.

Nice overview website:
https://ludens.cl/Electron/trafos/trafos.html
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