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Re: Reply: Neons....Parallel or Series?
From: Thomas McGahee[SMTP:tom_mcgahee-at-sigmais-dot-com]
Sent: Thursday, November 27, 1997 2:06 PM
To: Tesla List
Cc: megavolt-at-usa-dot-net
Subject: Reply: Neons....Parallel or Series?
>
> From: Matthew Mills[SMTP:megavolt-at-usa-dot-net]
> Reply To: megavolt-at-usa-dot-net
> Sent: Wednesday, November 26, 1997 1:14 PM
> To: Tesla List
> Subject: Neons....Paralell or Series?
>
> Hi, I just brought home my old Beacon Radio 15Kv 30mA Neon
> transformers. I have made a jacobs ladder to test them and can get them
> to arc over and rise up the ladder to 3inches apart. I paralleled the
> transformers and made sure I got my neons in phase (or is it out of
> phase?) and then the spark would arc out to almost 4 inches. Now my
> questions is ....
> I have heard that neons can damage each other if they are paralleled and
> one has a lwer voltage output than the other. Mine are both rated the
> same but when I got them I was told that they had dropped some of their
> rated output and that was why I could have them. There is a label on one
> of them which says 13.2Kv. Can I remedy this? can I still use them in
> parallel in a tesla circuit?
>
> Also, can I series link two neons or does this put 30kv through each
> winding and kill them?
>
> Please help,
>
> Matt.
>
********** Reply follows
Matt,
Congratulations on getting a nice pair of neons!
Here's the scoop on paralleling transformers:
When paralleled, both transformers are forced to be the same.
Now if you parallel two 15KV transformers, of course this is
just perfect. If you parallel a 13.2KV and a 15KV, then the
13.2KV will be pulled UP, and the 15KV pulled DOWN. How much
depends on the transformers.
Many coilers have successfully paralleled transformers that
were a bit mismatched. Some just strap 'em together and go for
it. (By the way, ALWAYS strap the cases together and also to
the AC ground. This is especially important when paralleling
neons, but should actually ALWAYS be done for the sake of
safety). Others try to share the load a bit more easily by using
a resistor to each HV bushing. Then the free end of the resistors
are paralleled. Since many coilers add such resistors anyhow
to supplement their choke protection scheme, this method is
quite attractive and very useful.
Your 13.2KV unit may be lower due to carbon tracking. Gary Weaver
posted a method of heating a neon in an oven to melt the tar. This
often corrects such problems without having to de-pot the neon.
If you try this method, be careful not to burn yourself. I use a
pair of viselocl pliers to hold the HV terminal bolts and I rock the
neon after the tar has melted. This greatly facilitates the tar
movement and carbon track removal.
As regards the question about putting them in series: DON'T! The
neons have a center tap to the case. They were NOT designed to be
connected that way. And besides, for Tesla coil use you will have
a hard enough time building caps robust enough to survive the 15KV
you already have. Learn from the accumulated wisdom on this list:
15KV is MORE than enough! Many coilers prefer 12KV neons because
it is easier to build decent caps for them.
Hope this helps,
Fr. Tom McGahee