[Prev][Next][Index][Thread]

Re: repair

Tesla List wrote:
> 
> >> > > > Subject: Re: repair
> >> Subject: Re: repair
> >> > > > Subject: Re: repair
> >Subject: Re: repair
> >> > > > Subject: Re: repair
> >> Subject: Re: repair
> >> > > > Subject: Re: repair
> 
> Subscriber: mhammer-at-misslink-dot-net Tue Feb  4 22:19:57 1997
> Date: Tue, 04 Feb 1997 15:25:14 -0600
> From: Mike Hammer <mhammer-at-misslink-dot-net>
> To: tesla-at-pupman-dot-com
> Subject: Re: repair
> 
> At 10:25 PM 2/3/97 -0700, you wrote:
> >> > > > Subject: Re: repair
> >> Subject: Re: repair
> >> > > > Subject: Re: repair
> >
> >Subscriber: unknown-at-apc-dot-net Mon Feb  3 21:51:44 1997
> >Date: Sun, 02 Feb 1997 01:17:02 -0800
> >From: Open Minded <unknown-at-apc-dot-net>
> >To: tesla-at-pupman-dot-com
> >Subject: Re: repair
> >
> >Tesla List wrote:
> >>
> >> > > > Subject: Re: repair
> >>
> >> Subscriber: major-at-vicksburg-dot-com Fri Jan 31 23:12:03 1997
> >> Date: Fri, 31 Jan 1997 23:38:56 -0600
> >> From: RODERICK MAXWELL <major-at-vicksburg-dot-com>
> >> To: Tesla List <tesla-at-poodle.pupman-dot-com>
> >> Subject: Re: repair
> >>
> >> Tesla List wrote:
> >> >
> >> > Maybe one of these days I'll take pictures and post them.
> >> >
> >> > Chip
> >> >
> >> >
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-> >
> Moderation in all things, including moderation
> >> > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-> >
> >> > On Wed, 29 Jan 1997, RODERICK MAXWELL wrote:
> >> >
> >> > > Tesla List wrote:
> >> > > >
> >> > > > Subscriber: major-at-vicksburg-dot-com Tue Jan 28 22:49:45 1997
> >> > > > Date: Tue, 28 Jan 1997 08:12:24 -0600
> >> > > > From: RODERICK MAXWELL <major-at-vicksburg-dot-com>
> >> > > > To: tesla-at-pupman-dot-com
> >> > > > Subject: Re: repair
> >> > > >
> >> > > > Tesla List wrote:
> >> > > > >
> >> > > > <SNIP>
> >
> >
> >
> >>   I just unpotted the first of four neon transformers that I got from a
> >> sign shop in town. The guy there told me they were 15Kv -at-30ma. I'm sure
> >> they are 15Kv but not so sure about the current rating as the plates
> >> have all been removed. I kind of went back to the dark ages in the way I
> >> removed the potting. I boiled them in oil! I used a burner out of a old
> >> space heater to heat the metal pan pan filled with diesel! I know this
> >> sounds dangerous folks but it was a good 20' away from anything that
> >> would burn including yours truly. It really speeds up the process as it
> >> uses solvent and heat to disolve the tar. Just don't try this at home
> >> folks! The core looks, and disassembles the same way discribed in the
> >> archives. One secondary reads megohm resistance and is probably fried.
> >> The other reads a little over 8kohms. Is this the usual resistance of a
> >> 15kv secondary? Or is this side shorted???
> >>
> >>                                  Frankensteins Helper
> >>                                         Max
> >
> >
> >High resistance (megohm region) indicates an open winding. A carbon-
> >shorted winding usually reads like a good winding as the short
> >resistance is quite high, though quite low enough for the HV!
> >
> >- Brent
> >
> >
> Yes Brent has that correct. You can't tell if a secondary has
> a carbon track short until you run it. And then it may not
> arc over until you run it on a coil.
> 
> Don't give up on a open secondary. Quite often only a few turns
> on the outside layer are damaged. I have removed as many as 40
> turns from a secondary to get down to good turns. The loss of
> a few turns wont affect the output much. Isolate the good
> free end and attach a new lead. Use small diameter stranded wire.
> I use 28 ga teflon covered stranded wire. Make a good solder
> connection and bed down the joint with an adhesive. I used hot glue
> and epoxy succesfully.
> My latest rebuild is getting coated with polyester resin. Not
> as convenient as epoxy but a lot cheaper.
> 
> Unless a secondary is really toasted it can usually be salvaged.
> 
> Mike Hammer
> mhammer-at-misslink-dot-net


   I'm going to clean up those old secondaries and save them for later
but I have my heart set on winding new secondaries. I have a couple of
books I've bought from Lindsay Publications. INDUCTION COILS by H.S.
NORRIE.  And   LARGE INDUCTION COILS a workshop manual by A.T. HARE.
Boyh books were written around the turn of the century but when it comes
to winding wire around and around how much can change? The only thing I
will do differently is use better and more modern insulating materials
between layers of the winding. From what I could tell without unwinding
it the primary has ~280 turns. So to get to my target voltage of 8Kv I
will have to wind 10,000 turns (clockwise) for each side of the
transformer. And after I remove a few shunts and add a pfc cap or two
more bang for the buck!