[Home][2014 Index] Re: [TCML] NIST High Voltage Laboratory Testing / Safety Reference [Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TCML] NIST High Voltage Laboratory Testing / Safety Reference



Bob,

I don't see any transformers in the photo list that you indicated, but with the description of a 100 amp line filter, I'd guess that the setup is for a utility pole (a.k.a. pole pig) transformer.

These usually were run backward to transform 240 VAC at high current into 5 - 25 KVA of 14,400 volt output, at a current rating depending on the size of the transformer in question. 5 or 10 KVA units were the most commonly used ones among TC builders, unless they were going for truly monster coils. Transformers bigger than 10 KVA tend to be unmanageably heavy unless you have a dedicated lab with a smooth concrete floor and a crane to handle them.

These were once readily available from D. C. Cox for something in the ~$250 price range, plus LTL truck freight shipping, which ran another $250. You could buy several for just a slightly greater S&H charge if they went to the same destination. I remember doing a group buy of 5 pieces for myself and 3 friends about 12 years ago.

Regrettably, D. C. has passed away and so has the last easy source of pole transformers available to the TC builder community. Another transformer rebuilding outfit that was once available to TC experimenters will no longer sell to mere mortals.

I did a quick scan of eBay, and found some reasonably suitable units in the $800 - 1500 range, plus shipping. If you are patient and lucky, you might find one at a lower price eventually. Large industrial potential transformers may get you from 0.5 to ~2 KVA in a single package, but these tend to be expensive, unless you are lucky enough to find one at a bargain price.

A series stack of 4 beefy microwave oven transformers can deliver a respectable ~8800 volts at ~500 mA, or ~4.4 KVA, which competes favorably with the best of the potential transformers, and is way cheaper.

Probably the best avenue now is to get one from another coiler who is moving on to SSTCs. The days of big iron disruptive coils are numbered, though IMHO they are simpler and more bullet proof than the SSTCs.

You might also investigate DC resonant charged TCs. I believe that Richie Burnett in England has a magnifier system that makes 10 foot discharges with only two microwave oven transformers in series as a power supply. These are a lot easier to acquire and transport, though the coil design is a bit more complicated.

Dave


On 8/31/2014 1:38 PM, rd_parker@xxxxxxxx wrote:
A couple of questions if I may: 1 - what would be the cost of a
transformer such as you are displaying, and 2) what is the expected
voltage generated and the voltage input? I am new to this 'hobby'.

Thanks,

Bob in Bellflower.

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla