DIY Transformer Winding

[GlidingDutchman]

Since this a very active DIY Audio forum I would expect that here is a few guys winding their own transformers.

I would like to pose a few questions:

Any tips for a new-bee transformer winder?
What can I use to build my own winding jig? What parts are essential?
What external tools are also required?

The reason for this is that here in S Africa the price of proper audio transformers are incredible and there is no real place here that specializes in audio transformer winding. Market is too small I guess.

 

[Geek]

Hi,

Yes, a few of us do actually 🙂

Here's my sloppy jig:
http://geek.scorpiorising.ca/GeeK_ZonE/index.php?topic=3476.0

Though I now use a magnet on the wheel and a Hall-effect sensor for the counter.


All you need is something that turns at a controlled rate hooked up to something that counts and voila! Instant roller.

Cheers!

 

[Steerpike]

I do occasional big (=lots of turns) ones on my metal turning lathe. I made a simple counter from an ICM7217 which can switch the motor off at a preset count. A photodiode "watches" a paint dot on the belt pulley.

Small coils - few enought turns to count in the head - I do on a old fashioned hand-drill, held in a vice.

 

[GlidingDutchman]

Thanks for the replies so far. It seems that there is no magical mysteries to winding transformers.

I saw on the RS Components site that a simple inductance meter can be bought for under $200.

 

[jackinnj]

I use a shuttle to wind toroids -- it's a small piece of thin wood, notched at each end.

When I am checking out a transformer I use a signal generator to send a 5kHz signal in one end and measure the ratio of input/output.

I've wound quite a few SMPS transformers this way -- with mystery cores -- life is simpler if you purchase cores from Amidon because you don't have to cut and measure -- works right the first time from the equations given, and you know how much heat it will take.

 

[GlidingDutchman]

I should probably as if there is any literature on winding techniques of audio transformers that would be a good supplement.

I studied the Hashimoto Electric Co. website with great care trying to absorb the "greatness" of their products - he-he!!

 

[Geek]

Here's some necessary math from our member mcs:
http://stiftsbogtrykkeriet.dk/~mcs/Transformer.html

Pat Turner of Turner Audio has some super info here (scroll down):
http://www.turneraudio.com.au/education+diy.htm

I have a couple of pages here:
http://geek.scorpiorising.ca/windingtransformers.html
http://geek.scorpiorising.ca/windingchokes.html


Cheers!

 

[GlidingDutchman]

Geek! Thank you for all the info. I am now reading your tutorial and it is great!

One thing I need to jog down somewhere is how to calculate the total number of windings and wire thicknesses.

 

[jackinnj]

If Pat Turner had a coffee machine in his basement, his wife would never see him.

 

[binspaul]

Hi,

I would like to wind a custom audio transformer. The following are the requirement parameters:
> Transformer Type: Audio
> Primary Impedance: 200ohm
> Secondary Impedance: 10kohm
> Turns Ratio: 1:1

How to compute the primary and secondary turns by knowing only the primary and secondary impedances ? I used the formula Xs/Xp and obtained the value as 500. Please confirm.

Best regards,
Bins.

If Pat Turner had a coffee machine in his basement, his wife would never see him.

 

[AndrewT]

a turns ratio of 1:1 makes the output impedance the same as the input impedance.
If you want to go from 10k:200r then
Turns Ratio = sqrt[10000/200] = 7.07:1

 

[TonyTecson]

Hi,

I would like to wind a custom audio transformer. The following are the requirement parameters:
> Transformer Type: Audio
> Primary Impedance: 200ohm
> Secondary Impedance: 10kohm
> Turns Ratio: 1:1

How to compute the primary and secondary turns by knowing only the primary and secondary impedances ? I used the formula Xs/Xp and obtained the value as 500. Please confirm.

Best regards,
Bins.

you have to know in advance your core dimensions to come up with turns...
what do you mean by turns ratio 1:1? you gave primary impedance as 200ohms and secondary impedance of 10kohms....
perhaps a complete circuit will gve us a clearer picture of what you intend to do...

 

[binspaul]

Hello Tony,

I would like to wind a transformer which is similar to Neutrik NTL1 (NEUTRIK|NTL1|TRANSFORMER, 1:1 | Farnell India)

Best regards,
Bins.

you have to know in advance your core dimensions to come up with turns...
what do you mean by turns ratio 1:1? you gave primary impedance as 200ohms and secondary impedance of 10kohms....
perhaps a complete circuit will gve us a clearer picture of what you intend to do...

 

[mnturner]

You'll struggle to wind something so small, very fine wires on tiny cores are difficult to handle.

A this transformer is 600Ohm:600Ohm.
As someone else already said, you need some data on the core you're using to calculate the number of turns required to prevent saturation and keep B in the correct range for your desired frequency response.

I'm in the process of my first (attempted) wind; a 420VA power trafo for a 2 channel, p-p AB2 6L6 stereo. If this works out, I'll wind the OPT's as well.

 

[rahkik]

transformer...

Hi,

I would like to wind a custom audio transformer. The following are the requirement parameters:
> Transformer Type: Audio
> Primary Impedance: 200ohm
> Secondary Impedance: 10kohm
> Turns Ratio: 1:1

How to compute the primary and secondary turns by knowing only the primary and secondary impedances ? I used the formula Xs/Xp and obtained the value as 500. Please confirm.

Best regards,
Bins.

can u tell me how to calculate transformer data...
send me as soon as possible thankyou...............