From: Alan Pearce <kiwiantipodean@googlemail.com>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
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Date: Wed, 15 Jul 2020 12:16:22 -0700
Subject: Re: [EE] Microwave Oven Transformers
Thread-Topic: [EE] Microwave Oven Transformers
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Rather than bundle the wire together before binding it I would try to
lay the four lots side by side and then bind it so it is a flat wide
strip. This will make it easier to wind on the core.

On Wed, 15 Jul 2020 at 19:29, Bob Blick <bobblick@outlook.com> wrote:
>
> Hi Graham,
>
> The choke is only going to be used at low voltage so you're right, I don'=
t need to worry too much about insulation.
>
> I could strip off the insulation and bundle the four strands together bef=
ore insulating. It would be rather stiff, but I've got tough fingers. Would=
 use a lot of polyimide tape, I expect it to be about 30 turns. The widest =
I have is 30mm I think.
>
> Varnishing it is an interesting thought. I've got no experience with varn=
ish or shellac, so finding something that would work from my local hardware=
 store will be an interesting experiment.
>
> I have some 8AWH battery cable too. But probably not enough.
>
> Thanks for the ideas!
>
> Bob
> ________________________________________
> From: piclist-bounces@mit.edu <piclist-bounces@mit.edu> on behalf of grah=
am foulkes
> Sent: Wednesday, July 15, 2020 10:57 AM
> To: Microcontroller discussion list - Public.
> Subject: Re: [EE] Microwave Oven Transformers
>
> HI
> 120 amp windings at low voltage, you don't need thick insulation on the
> wire. Maybe strip off the house cable insulation and lap wind with thin
> tape, electronic polyamide high temperature tape preferrably. I have used
> thin cotton tape to insulate scondary coils in a home built welder, still
> running 30 years later.
> Shellac lacquer is also an alternative, does not soften much with
> temperature increase and has good dielectric properties. Avoid PVC
> electrical tape, softens too easily and punctures when winding, stretches
> and so thins out.
>
> On Wed, Jul 15, 2020, 7:38 AM Bob Blick  wrote:
>
> > That's pretty nice! I guess I shouldn't give up on finding a source for
> > enameled wire. I will start with my current plan and see how much
> > inductance I get, since I have lots of house wire.
> > Thanks, Bob
> >
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