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A fixture for making multifilar windings

 

I took a break from organizing my shop to make this. I finally have a place to put things, so progress has been rapid. In 1/2 of the mess ;-(

I made something similar out of a very light oak strip which bent like a bow when I was making and testing transformers for my electrically tuned xtal filter project.

Here is the Mk II version with a stout enough piece of wood.? The aluminum angle bridges serve to position the wires properly side by side. Once they have been stretched so the wires undergo plastic deformation, a thin coating of nail polish, lacquer or super glue will produce an easily handled multifilar winding.? For this demonstration I made a 4 filament winding of #28. Before I wind this on a toroid, I'm going to spray one side with F77 spray adhesive so that it sticks to the core (I hope!).

I strongly suspect that two screws and the angles are probably good enough, but I have had the tuner for ~50 years so I put it to use. Up until the advent of neodymium magnets, repairing a guitar side used a thin wire through the crack to pull gluing cauls together. This tuner came off my Yamaha FG-180 when I put Grovers on it.

Have Fun!
Reg

IMG_4333.JPG
IMG_4334.JPG
IMG_4335.JPG
IMG_4336.JPG

 

Bravo, we used to just use a vise and electric or hand drill.

no need for any coating if done properly

in production we bought multifilar wire in 2..4 colors for ID of wdgs. MWS makes it.

Jon
 

Someone should have told Raymond Mack and Jerry Sevick. One or the other went to a lot of trouble to keep the windings parallel instead of twisting them as shown in the cover photo of the 5th ed.

I plan to compare the performance of twisted and parallel windings at some point, but rather low priority.

Have Fun!
Reg


On Saturday, February 17, 2024 at 10:59:39 AM CST, Froggie the Gremlin <jonpaul@...> wrote:


Bravo, we used to just use a vise and electric or hand drill.

no need for any coating if done properly

in production we bought multifilar wire in 2..4 colors for ID of wdgs. MWS makes it.

Jon
 

Hello again

Bunched or twisted wires are used in magnetics as a low cost more practical alternative to Litz wire. Depend on the frequency and current density, the difference between bunched and litz may be slight.

Certain winding designs indeed use a bifillar pair to minimize leakage inductance.

In decades of magnetics I have never used multiple wires that laid parallel. in production it's impossible to maintain the lay.

Rubudue and MWS make Litz and bunched wire, they may have an app note comparison.

Bon courage

Jon
 

This is the cover photo which prompted developing a way of making flat multifilar windings. There is not a single example or any discussion of twisted windings in the book. If you have citations comparing the two methods I'd be very interested.

Rather obviously both the inductive and capacitive coupling will be different for the two methods.

Have Fun!
Reg

On Saturday, February 17, 2024 at 02:30:05 PM CST, Froggie the Gremlin <jonpaul@...> wrote:


Hello again

Bunched or twisted wires are used in magnetics as a low cost more practical alternative to Litz wire. Depend on the frequency and current density, the difference between bunched and litz may be slight.

Certain winding? designs indeed use a bifillar pair to minimize leakage inductance.

In decades of magnetics I have never used multiple wires that laid parallel. in production it's impossible to maintain the lay.

Rubudue and MWS make Litz and bunched wire, they may have an app note comparison.

Bon courage

Jon






IMG_4341.JPG

 

you want parallel multifilar wire, made in various numbers of conductors



Jon
 

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Interesting. That appears to be exactly the same photo as is on the cover of Jerry Sevick's book on baluns and ununs.

DaveD

On Feb 17, 2024, at 16:19, Reginald Beardsley via groups.io <pulaskite@...> wrote:

?
This is the cover photo which prompted developing a way of making flat multifilar windings. There is not a single example or any discussion of twisted windings in the book. If you have citations comparing the two methods I'd be very interested.

Rather obviously both the inductive and capacitive coupling will be different for the two methods.

Have Fun!
Reg

On Saturday, February 17, 2024 at 02:30:05 PM CST, Froggie the Gremlin <jonpaul@...> wrote:


Hello again

Bunched or twisted wires are used in magnetics as a low cost more practical alternative to Litz wire. Depend on the frequency and current density, the difference between bunched and litz may be slight.

Certain winding? designs indeed use a bifillar pair to minimize leakage inductance.

In decades of magnetics I have never used multiple wires that laid parallel. in production it's impossible to maintain the lay.

Rubudue and MWS make Litz and bunched wire, they may have an app note comparison.

Bon courage

Jon






<IMG_4341.JPG>
 

That is the photo on the cover of the 5th ed.

I already have a complete stock of single filament magnet wire. For a hobby user buying rolls of multifilar wire doesn't make sense given the ease of making my own to order.

Especially given that I can change wire sizes at will for a single winding. So a 6 strand primary with 2 secondaries of lighter gauge is easy to make.


On Saturday, February 17, 2024 at 03:59:40 PM CST, Dave Daniel <kc0wjn@...> wrote:


Interesting. That appears to be exactly the same photo as is on the cover of Jerry Sevick's book on baluns and ununs.

DaveD

On Feb 17, 2024, at 16:19, Reginald Beardsley via groups.io <pulaskite@...> wrote:

?
This is the cover photo which prompted developing a way of making flat multifilar windings. There is not a single example or any discussion of twisted windings in the book. If you have citations comparing the two methods I'd be very interested.

Rather obviously both the inductive and capacitive coupling will be different for the two methods.

Have Fun!
Reg

On Saturday, February 17, 2024 at 02:30:05 PM CST, Froggie the Gremlin <jonpaul@...> wrote:


Hello again

Bunched or twisted wires are used in magnetics as a low cost more practical alternative to Litz wire. Depend on the frequency and current density, the difference between bunched and litz may be slight.

Certain winding? designs indeed use a bifillar pair to minimize leakage inductance.

In decades of magnetics I have never used multiple wires that laid parallel. in production it's impossible to maintain the lay.

Rubudue and MWS make Litz and bunched wire, they may have an app note comparison.

Bon courage

Jon






<IMG_4341.JPG>
 

Reginald here is the bifilar wire in our stock, 2X#29 solderable magnet wire twisted pair, and 2X #30 Kynar.

These are used in many bifilar chokes, toroid's, etc.

Twists minimize CM emission.

Jon

bifilar.jpeg

 

Jon,

I am not interested in debating the merits of whether to use twisted or not. The sole purpose of this thread is to demonstrate the mechanism I built for making custom parallel windings.

Sometimes this matters and sometimes it doesn't.

I have *ZERO *interest in *MY WAY IS BETTER*. Absolutely do not care at all. All I have tried to do is document a technique I find useful which is also simple and inexpensive for one off projects.

Lutherie meets electronics.

Have Fun!
Reg


On Saturday, February 17, 2024 at 05:52:32 PM CST, Froggie the Gremlin <jonpaul@...> wrote:


Reginald here is the bifilar wire in our stock, 2X#29 solderable magnet wire twisted pair, and 2X #30 Kynar.

These are used in many bifilar chokes, toroid's, etc.

Twists minimize CM emission.

Jon





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