Re: 10KV RMS -at- 300MA transformer

           Re: 10KV RMS -at- 300MA transformer
           Sun, 06 Apr 1997 14:09:11 -0400
           "Edward J. Wingate" <ewing7-at-frontiernet-dot-net>
           Tesla List <tesla-at-pupman-dot-com>

Tesla List wrote:
> Subject:
>             10KV RMS -at- 300MA transformer
>        Date:
>             Wed, 02 Apr 1997 10:53:55 -0800
>        From:
>             Skip Greiner <sgreiner-at-wwnet-dot-com>
> Organization:
>             Greiner, Ltd.
>          To:
>             tesla list <tesla-at-pupman-dot-com>
> Hi everyone and especially those who purchased these transformers
> I have bitten the bullet. I have made the decision to go ahead and
> modify my two transformers and operate them at their full 5000v rating
> using the resonator cap in series anti parallel.
> Last night I started to take the first one apart. It took almost 1 hour
> to get thru to the HV terminals. I found two potential (pun intended)
> problems, maybe three. First, the varnish impregnation in my units is
> still very soft, almost sticky. Before I fire these beasts up for real,
> I may let them cook for a few days with some kind of load to see if this
> stuff will cure. The next problem is voids down inside. There are air
> spaces and these are probably able to breath and suck in humid air.
> Eventually they might be prone to cause arc-over. I doubt that running
> these things in oil will do much to stop this problem. I plan to open as
> much of the covering around the HV winding as I can and flood it with
> corona dope. The next problem may be in the soldering of the HV winding
> leads to the the terminals. I found burned spots around the terminals
> from the soldering iron which might lead to carbon tracking. I am
> removing he terminals anyway and the burned spots go with them. The last
> item has been mentioned before. That of the lead from the inside of the
> secondary. It only has a very thin piece of spaghetti over it, which is
> totally inadequate for our purposes. I am adding a major amount of
> additional insulation and a generous amount of corona dope. I will also
> be adding the safety gaps to each transformer as previously suggested.
> I then plan to run the anti paralleled transformers on a small TC and
> then progressively larger ones until I get to their max power or burn
> them out.
> Fr. MaGahee: At one time you mentioned that you thought these
> transformers have large wire in the secondaries. Do you know what size
> it is?
> Well, that's it for now. Will report further as I get into this
> Skip


I just cut some of the secondary wire off one of these transformers and
miked it at .0125" which, acording to my chart is #28 AWG. I hope this

Safe Coiling Always,

Ed Wingate