Re: Variac rebuild

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Blake Hartley <teslaspud@xxxxxxxxx>

Hello all,

I got around to trying to wind the variac, and there is a problem: no
matter how hard I try, I cant get the wire on the inside to form two
layers. I would give up, but I have a small spool of 20 AWG wire and a
chunk of iron that isnt going anywhere fast, so I am going to make one
layer on the inside of the form, which will half the number of turns,
making it 148. Would this work well ( i am running on 120 AC)? Also, i
am going to put the tap points on the 23rd turn from both sides. Any
comments on this design would be much appreciated.

Cheers,
Blake


On Thu, 03 Feb 2005 07:30:27 -0700, Tesla list <tesla@xxxxxxxxxx> wrote:
> Original poster: Finn Hammer <f-h@xxxx>
>
> Blake,
>
> Looking at thoseindustrial variacs, I tend to think I am loking at a
> genuine example of industrial art.
> Getting the wire trough that small hole in the center is the hard part, as
> I see it. That`s why I had the core made so big for my project. Not so neat
> and refined as the professionally evolved types, but manageable on a hand
> work level.
> Another thing, the contact area: on pro stuff, the wires are rolled flat,
> you will have to file it flat, which decreases the cross section. more heat
> in a critical spot.
> I see these hand winding endeveours as zen activity, more than anything,
> and rewarding as such.
> I wish you luck!
> Cheers, Finn Hammer
>
>
> Tesla list wrote:
>
> >Original poster: Blake Hartley <teslaspud@xxxxxxxxx>
> >
> >All,
> >
> >Maybe you remember, but a while ago my four amp variac brokedown due
> >to several burned and broken turns. Seeing Finn Hammers homemade
> >variac inspired me to dig up the remains to see if it would be
> >possible to rebuild. I took all of the stuff off except for the core
> >and windings, and the physical specs of the core are as follows:
> >height=2.9", ID=2", OD=4.1". It is wound 45 turns until the first tap
> >point, 206 turns in between the two tap points, and 45 more turns
> >until the last turn. The inside is two layered, but the outside is
> >single layered (because the inside radius is ~ half the outside
> >radius.) I plan to figure out the type of wire and re-wind it in the
> >same manner as it was wound. would this work, or is there any other
> >way i should go? Any help would be much appreciated. Thanks
> >
> >Cheers,
> >
> >Blake
> >
> >
> >
>
>