Re: xfrmr rewinding, was: Re: SECONDARY WINDING AND COATING JIG

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Dukester by way of Terry Fritz <twftesla-at-uswest-dot-net>" <dukester-at-home-dot-com>

Hi Pete,
Actually it was 300ma. At 117 volts, it put out 13,400v at 260ma.(measured).
I ran it up to 125v an my variac to see if it would saturate. That's where I
get the 14/300 from.  When I put it back together, I took out all but 8
shunts in each pack out of the original 22, so I would still have some
current limiting.30 ga wire will give me about a 50% duty cycle dry, and
even more in oil, which is more the ample for a Tesla coil.

Catch you later,
Sparky

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, April 26, 2001 10:59 AM
Subject: xfrmr rewinding, was: Re: SECONDARY WINDING AND COATING JIG


> Original poster: "Peter Lawrence by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <Peter.Lawrence-at-Sun-dot-com>
>
> Sparky,
>        400ma, was that by design or what. Did you just remove all shunts,
> or just some, if so how did you decide how many - trial and error or
> computed. Did you actually measure the short circuit current (like Terry
> suggests with a voltmeter across a 1kohm (high wattage) resistor shorted
> across the output?).
>
> I'ld like to know how to design for a given short-circuit-current, but
I've
> not seen anything describing how (how to design a non-current-limited
power
> transformer is described very well in "Roll your own power transformers"
> at   http://members.tripod-dot-com/~schematics/xform/xformer1.htm   but this
> gives no clue about current-limited transformers.
>
> The power transformer web page suggests #24 to #25 wire for 400 ma (1 to
.75
> CircMils per ma) for continuous duty. I take it you've not had any
problems
> with #30 though, presumably since TC usage is typically very very low duty
> cycle.
>
> -Peter Lawrence.
>
>
>
>
> >Original poster: "Dukester by way of Terry Fritz <twftesla-at-uswest-dot-net>"
> <>dukester-at-home-dot-com>
> >
> >Will,
> >Been there, done that. I have rewound a Franceformer 15/60, it is now a
> >14/300. Works good! I started winding it by hand on a home built winder
that
> >I made out of  MDF shelving. I was guiding the 30ga. wire by hand, but
found
> >it too difficult to keep the winding even and not overlapped. I designed
an
> >auto-feed that was driven directly from the spindle that I could adjust
the
> >speed of the feed by changing drive wheel sizes. I used a third wheel in
> >between the two drive wheels to reverse the feed. It's designed loosely
> >after Terry Fritz' winder but without the fancy computer controls. If you
> >build one, skateboard bearings work good for all the rotating parts.
> >
> >Later,
> >Sparky
>
>
>
>
>
>