Re: Primary Coil Power Supply...

Subject:  Re: Primary Coil Power Supply...
  Date:   Thu, 12 Jun 1997 17:06:22 +0200
  From:   tesla <tesla-at-ixx.se>
    To:  Tesla List <tesla-at-pupman-dot-com>

At 09:18 1997-06-12 -0500, you wrote:
>Subject:  Re: Primary Coil Power Supply...
>  Date:   Wed, 12 Feb 1997 12:31:19 +0100
>  From:   Schwalbe <schwalbe-at-augustine.demon.co.uk>
>    To:   tesla-at-pupman-dot-com
>>Subject:  Primary Coil Power Supply...
>>  Date:   Thu, 12 Jun 1997 12:20 +0200
>>  From:   NEIL HURSEY <ETL.ETLNLHY-at-MESMTPSE.ericsson.se>
>>    To:   tesla-at-pupman-dot-com
>>--- Received from ETL.ETLNLHY +44-1483-303666        97-06-12 12:20
>>  -> tesla-at-pupman-dot-com
>>Hello All,
>>I'm trying to build my first Tesla Coil in the UK and am having
>>trouble trying to find a suitable transformer to drive the primary
>>The best I've found so far is microwave oven transformers with a
>>2KV output.
>>Does anyone know if these transformers could we wired in series,
>>say 5 transformers to produce 10kv output?
>>There are three main problems that I can see with this:
>>1)  The transformers have slightly different specifications.  Could
>>    this cause a phase problem in connecting them in series?
>>2)  Each transformer is capable of drawing about 1KW of power.
>>    What would be a good method of limiting the current?
>>3)  One end of the secondary coil of the transformers is soldered
>>    to the earthed casing of the transformer.  However, this could
>>    be removed and connected to a separate terminal.
>>If any of you can help with these questions, or perhaps suggest
>>another transformer source in the UK it will be much appreciated.
>        I've had the same problems in the UK trying to find a source of
>transformers for my first coil. The only idea I've had is  to buy
>transformer kits from Maplin, wire them up for 12.5 KVac, then put them
>parrallel??? to raise the Current. The only other possibility is going
>to a
>neon sign shop, and buying one from there. I guess if you are really
>adventurous you could try to get hold of one of those transformers that
>supply electricity to houses away from sub-stations, directly from the x
>supply lines, and wire it up in reverse..perhaps this is a little to
>powerful, but a good investment for future coils. Does anyone know how
>a  'pole pig' costs? If you could limit the current from the 'pole pig'
>could use it for a less powerful coil, then when you a feeling brave
>with a
>larger coil it will become very useful.
>                                        Tom Schwalbe

Hi Tom and Neil.

I have similar problems here in sweden but there are some ways to get
of nice transformers. You should try a neonsign or any sign company.
do have transformers but my problem here is that they don't want to give
them away and prices the old ones nearly as high as the new ones. Try
of these places first and check out their pricing.

Then you could try to find some furnace transformers. They are robust
the companies around here are more willing than neonshops to give old
for free or little money. Usual rating is 2x6kV (centertapped at the
23mA or more(maybe less) . I have tried some and they all worked fine
not using the case for ground and using the terminals for 12kV. Any such 
transformer should work fine. They are current limited like the neons.
(ok, not all but i haven't found any so far that isn't)

If all else fails try finding a pole pig. I have two ways that i tried
One, call your any railway company that has some sort of construction
and try to persuade them to sell one of their transformers. That are
similar to ordinary power distribution transformers only difference is
thay might be rated at a different Hz than 50 or 60. Mine were rated 16
This is where i found my three "pigs".I was lucky to get them from a
down part for just 80$.
2 10kV 220mA an one 10kv 440mA.
And the last to try is on of your power distribution companies and try

There are of course other more specialized places to get hold of high kV
transformers but it is much more difficult. Power supplies to radars,
or semi old radio transmitters and such. The military has many strange
wich include high voltage.

I have successfully wired some 4kV/45mA neons in series for 8kV. I use 3
in paralell for 8kV/135mA and they haven't failed me so far. I might
just be
lucky or the lower voltage neons might handle such wiring better than 12
15 kV neons. I don't know......

Any way, good luck!

              Matthias Andersson
       -"Why am i glowing in the dark???