Re: HElllP!, did I fry my NST?

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

Original poster: "Christopher Boden by way of Terry Fritz <twftesla-at-qwest-dot-net>" <chrisboden-at-hotmail-dot-com>

Ok, that's good :)

If one side is dead, then the other side is good. This means that you've 
still got a working Primary winding. The most likely problem is a Carbon 
Track inside the case running through the tar. First, let's cover the 
concept of Windings.

Inside an NST are 3 coils of wire, wound on a common frame of steel plates 
(this frame is called a Core). They work by using electromagnetic fields to 
trade Volts for Amps. This is the basis for all Transformers. Since there is 
no free lunch (2nd law of thermodynamics and all that rot) if you raise 
voltage, you loose amperage. In the end if you put 100 Watts (the unit of 
energy) in, you get 100 Watts or less out. You never get more out than you 
put in, in fact, you can't break even.

The first winding is in the middle. It's made of thick wire and is called 
the Primary Winding. Each end of this connects to a Low Voltage Terminal on 
the side of the case. These are the two terminals that you connect to your 
house power.

The other two windings sit on either side of the primary. These are 
Secondary Windings and are made of very thin wire (like, Hair thin) because 
while they carry a lot of voltage, they don't carry much Amperage.

Ok ok ok, Volts and Amps.....

Think of a wire like a pipe. The Pressure of the water in the pipe is like 
Voltage. It's the push, or Potential Difference (like a waterfall). Amperage 
is like the AMOUNT of water that flows past a given point in the pipe in a 
given amount of time. Volts X Amps = Watts. So if you have 100 Volts at 10 
Amps you have 1000 Watts. But if you use a transformer to raise that to 1000 
Volts you can only get 1 Amp out for 10 Amps in. No matter what, you'll 
always have 1000 Watts.

This means that you can carry a whole BUNCH of power through a very tiny 
wire if you have gobs of Voltage behind it. This is the basis for our whole 
National Power Grid :)

Each Secondary winding has one side connected to the Core. This is a safety 
feature that keeps the core from "Floating" to a high voltage and knocking 
you on your butt if something goes wrong. This is called "Center Tapped". 
The other end of each Secondary winding connects to either of the High 
Voltage terminals on the sides of the case. So now you see, we have 3 
seperate windings.

These are all encased in a thick, black tar. When it cools it holds 
everything still and protects it from the massive abuse you're about to put 
it through.

What has happened is a tiny arc has burned it's way from one of the High 
Voltage secondary windings, through this tar, to the case. When it burns 
it's way through, it turns the carbon to ash, Ash is made of Carbon (like 
charcoal basicly), and it has one nasty side effect. It happens to conduct 
electricity. All the energy from that winding is going right back to the 
case and not to your coil.

The only way to fix it is to remove, or disturb the Carbon Track. You can do 
this in 2 ways.

1. Take the lid off the NST, cut the case off, and attack it with a hammer 
to chip off the tar. This sucks, it makes a huge mess, and it will likely 
destroy the hair thin wires.

2. Cook it...a lot. This sucks too, but worse! You have to heat up the NST, 
REALLY hot, and it takes hours and hours to do. When it's hot enough, the 
tar melts. Then you can either pour off the tar and rebuilt the NST. Or you 
can simply slosh it around gently. This stirs the tar and moves the ash 
around enough to break up the carbon track. It's not a guarenteed cure 
(nothing is) but it's very likely to work.

The downside is it STINKS! And not a gentle fart in church stink, but it's 
more like a dead raccoon under your porch in july stink. If you use the oven 
to cook the NST, you'll never make food in there again (unless you develop a 
taste for creosote, which tastes somewhere between Vegemite and Railroad 
ties). Same thing with using the grill, plus it will stink up the house 
either way.

So that's the basics of NSTs. Any questions?

And no flack from the physics, electrical engineering, or math gods! This is 
not intended to be a EE-101 class and I'm allowed some artistic discretion 
on the whole Water in a Pipe thing :)

Christopher "Duck" Boden Geek#1
President / C.E.O. / Alpha Geek
The Geek Group
www.thegeekgroup-dot-org
Because the Geek shall inherit the Earth!

"He had that rare weird electricity about him--that
extremely wild and heavy presence that you only see in
a person who has abandoned all hope of ever behaving
normally." --Hunter S. Thompson


>Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
><PLUGHzz-at-aol-dot-com>
>
>In a message dated 10/16/2002 10:33:26 AM Pacific Daylight Time,
>tesla-at-pupman-dot-com writes:
>
>
> >
> > Original poster: "Christopher Boden by way of Terry Fritz
> > <twftesla-at-qwest-dot-net>" <chrisboden-at-hotmail-dot-com>
> >
> > Unconnect EVERYTHING from the High-Voltage side of your NST.
> >
> > See if you can draw an arc from each HV terminal to the case, and from 
>one
> > HV terminal to the other.
> >
> > If you can do all this, then it's good. If one side is dead (very 
>common)
> > then you cooked your NST.
> >
> > They do make wonderful doorstops though :) and DONT THROW IT AWAY (never
> > throw ANYTHING away), in a couple years when you get really good at 
>coiling
> > you will get this strange urge to broil your dead NST in hopes of 
>bringing
> > it back to life. It can be done, but it's a filthy, stinky process that 
>can
> > end a marrige.
>
>
>
>
>
>One side is dead. Can this be fixed by heating the tar up? or how can I fix
>this?