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Taser transformer

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Njubster

Sun Nov 18 2012, 05:53PM

Registered Member #6857 Joined: Sat Sept 22 2012, 08:25AM
Location: Srbija, Novi Sad
Posts: 40

Patrick wrote ...

Njubster, do you have access to the oil-can type ignition coils in your country? you can cut the metal tube-case open pull out the secondary, put in your ferrite bar, and then wind a simple primary. then youd have a 4cm round by 6cm long cylinder.

Probably, I don't know, never seen or heard of that before :) But I have a feeling it's quite expensive cause it's a car part. Beside, I wouldn't be able to cut metal here, I am far away from my home and my tool shed, so all I can do here is solder and tape :)

And the above thing, you think it will work?

Patrick

Sun Nov 18 2012, 06:31PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

my idea will work and is cheap, but if you dont have more than solder or tape capacbility HV'ing is going to be a hard road ahoe...

Tony Matt

Sun Nov 18 2012, 09:18PM

Registered Member #3700 Joined: Sat Feb 19 2011, 12:59PM
Location:
Posts: 107

Hi !

Wind a coil or a transformer is pleasure task, if you has pacience... \

But you need some apparatus and good direction

Fist of all, do not wind the wires over the ferrite. Just provide a form between the ferrite and the winding. The form has to allow ther ferrite enter and exit very free inside.
Lets say that you ferrite has 9mm diameter, then your form shall have 9.2 - 9.5 mm INTERNAL diameter. The form outside diameter may be 11-12 mm
The form may be constructed with kraft paper and glue. Leave to dry to dry 2- 3 days ( Kraft paper is that one brown, 0.1 to 0.2 mm thick...)

At this mean time you may construct a winding machine, crankcase style!
See the aparatus:

The C clamp is used to clamp the wood frame in the table, The turn count devices is used tho count the turns. You do not need, it is only 1000 turns, use a paper pad to mark a tic every time that you complete 100turns.

Wire #32AWG(0.2mm) is ok, as wel as #30, or #28 The wire you may save from old tv deflection coils.
Do not put more than 200turns per layer, otherwise you may have one internal arc failure. In the picture the coils has only 35turns per layer.

Do not use oil, Just keep all dry.

Keep in touche,

Regards

Newton

EDIT : beteew the layers i use Mylar (polyester paper 0.1mm, that one transparent the engineers use to draw ) double insulation in order to get 500V insulation between the coil turns. You may use kraft, 4 Kraft in each layer insulation .

Njubster

Mon Nov 19 2012, 03:53PM

Registered Member #6857 Joined: Sat Sept 22 2012, 08:25AM
Location: Srbija, Novi Sad
Posts: 40

Tony Matt wrote ...

Hi !

Wind a coil or a transformer is pleasure task, if you has pacience... \

But you need some apparatus and good direction

Fist of all, do not wind the wires over the ferrite. Just provide a form between the ferrite and the winding. The form has to allow ther ferrite enter and exit very free inside.
Lets say that you ferrite has 9mm diameter, then your form shall have 9.2 - 9.5 mm INTERNAL diameter. The form outside diameter may be 11-12 mm
The form may be constructed with kraft paper and glue. Leave to dry to dry 2- 3 days ( Kraft paper is that one brown, 0.1 to 0.2 mm thick...)

At this mean time you may construct a winding machine, crankcase style!
See the aparatus:

Wow that's very detailed and helpful, thank you!

But there's one more thing I'd like to know: after winding the entire transformer, I end up with two very thin wires on each side. How do you solve that so they are nicely and practically soldered to a bigger wire? How do you make it strong? I'm very much afraid that I will rip them off by accident, or destroy them by some spark :/

Ash Small

Mon Nov 19 2012, 04:29PM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

You can slide some tubing (maybe some insulation from another wire, or heatshrink tubing, or something similar) over the end before you start winding, If you secure the inner end, it will protect the wire quite well. You can use a similar piece of tubing on the other end, secured in place with insulating tape. This helps to stop the wire breaking close to the coil.

Another option is to solder some insulated leads, made from multi-strand wire, and use these for the lead in and lead out, but you'd need to insulate the soldered joint.

Enamel paint or varnish is good for this, but use an oil based or polyurethane based paint or varnish, or use a piece of tubing as described above.

Tony Matt

Mon Nov 19 2012, 04:58PM

Registered Member #3700 Joined: Sat Feb 19 2011, 12:59PM
Location:
Posts: 107

Thanks for the questions.

Working with fine wire (#32AWG #30AWG ) is difficult and requires a lot of care and pacience.. ...

First cut the insulation kraft paper or polyester insulation in ribows, the ribows are the same width of the ferrite core, and lenght may be more or less 1meter long.

At this time the paper form ( same lenght of ferrite ) has to be very dry and hard enough to support the presure of the windings.

Keep in mind all time that the lenght of a wire layer has to be 10mm smaller than the insulation ribow widht, in such way that every wire layer have two margens if 5mm. (otherwise enverthing will collapse). These 5mm margens also provide the insulation for creepage.

The thich wire( #22 and thicker) does NOT need a flexile wire lid. Just leave the wires termination out of the coil. See the picture in the last post.

But for a winding of thinner wire, #28 and up, use a thin flexible wire pvc insulated as a lid.
First remove 20 mm of the varnish from the (#32) wire to allows the sordering.
Remove 10 mm of the insulation of both sides of the lid pvc wire,
Wind 3-4 turns of the #32 wire over the conductor of the lead, and solder.
With very small lenght of masking tape fix the lid on the form,
Keep the 5 mm margen.
Add one turn of ribow over the the lid wire, and start to wind the #32 wire.
As soon complete the the first layer, add one turn of insulation ribow on top of first wire layer and continue to wind the #32 wire .
And so and so ...
In the end add one turn of insulation ribow on top of the last wire layer, fixing this ribow with small portion of masking tape and fix the end of the wire winding, with masking tape.
Remove the varnish of the thin wire, and solder with the second lid wire.
Fix the lid wire on top of insulation ribow and add one or two turns of insulation ribow on top.
Tie the coil with 20 -30 turns of thin thread.
Leave 3hours driyng under a light bulb, and imerse 10 minutes in a insulating vernish.
The vernish that I have used is a alkid resin vernish, the Glyptal from G.E, But you may use any kind of clear transparent oil base (carriage, boat varnish, exterion for wood, Etc )

When everything is dry you may wind the tick wire, add 4-5 layers of insulation between primary and secondary.

Give the complete ferrite core dimensions.

Regards

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