From: Bob Blick <bobblick@outlook.com>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
Sender: "piclist-bounces@mit.edu" <piclist-bounces@mit.edu>
Date: Mon, 13 Jul 2020 13:53:48 -0700
Subject: Re: [EE] Microwave Oven Transformers
Thread-Topic: [EE] Microwave Oven Transformers
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Hi Richard,
The laminations aren't interleaved, and I can't imagine they'd want to weld=
 if there were varnish or epoxy. So they probably varnish after the whole t=
hing is assembled. In that case I can't imagine the bond being very strong.=
 I can always cook it in the toaster/reflow oven for a while to soften it u=
p.
Cheers, Bob

________________________________________
From: piclist-bounces@mit.edu <piclist-bounces@mit.edu> on behalf of Richar=
d Prosser=20
Sent: Monday, July 13, 2020 1:36 PM
To: Microcontroller discussion list - Public.
Subject: Re: [EE] Microwave Oven Transformers

Even with the welds cut I'd thought that the laminations would be tight
(Not fall apart). They may be epoxied in place as well. Otherwise there
would be a strong buzz when operating. I haven't used microwave
transformers (yet), but had a holiday job assembling speaker transformers
and power supply chokes.
RP

On Tue, 14 Jul 2020 at 08:17, Bob Blick  wrote:

> Yes, that's why I thought it might be relatively easy, assuming everythin=
g
> didn't fall apart when I cut through the welds. This guy seems to have
> achieved it:
> https://www.youtube.com/watch?v=3DrCqddXhoP4E
> Cheerful regards, Bob
>
> ________________________________________
> From: piclist-bounces@mit.edu <piclist-bounces@mit.edu> on behalf of Alan
> Pearce
> Sent: Monday, July 13, 2020 12:51 PM
> To: Microcontroller discussion list - Public.
> Subject: Re: [EE] Microwave Oven Transformers
>
> I would have thought that a DC choke would not want the E and I
> laminations interleaved, rather an air gap to limit saturation of the
> core.
>
> On Mon, 13 Jul 2020 at 18:39, Denny Esterline  wrote:
> >
> > Personally, no. But the internet is full of people that have taken out
> the
> > secondary windings and wound on 2-3 turns of heavy wire to produce a sp=
ot
> > welder.
> > Google around a bit on DIY spot welder and I'm sure you find lots of
> people
> > hacking up these transformers in interesting ways. Probably something
> > relevant to be learned there.
> >
> >
> > -Denny
> >
> > On Mon, Jul 13, 2020 at 9:23 AM Bob Blick  wrote:
> >
> > > I am in need of a large DC choke and thinking about making one from a
> > > microwave oven transformer. It appears that the E's and I's of the
> core are
> > > not interleaved so all I need to do is cut the weld holding the core
> > > together and it should fall apart. Hopefully in just two pieces. Then
> I can
> > > strip out the windings, put my own winding on, and, most importantly,
> > > sandwich a spacer so I have a gap (I said this was a DC choke).
> > >
> > > Anyone here ever play with microwave oven transformers at this level
> and
> > > learned any hard lessons?
> > >
> > > Thanks, Bob


--=20
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