operating pole pigs

This forum is for specialized infomation important to the construction and safe operation of the high voltage electrical supplies and related circuitry needed for fusor operation.
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HighVoltageFox
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operating pole pigs

Post by HighVoltageFox » Wed Jan 11, 2006 1:20 am

It has been difficult to find any info on pole pig operation for me. I want to understand how to use them so I would not venture into dangerous territories with out information, if I do decide to use a pole pig.

Just so you know, I am not going to try using such a high voltage and amperage in a fusor with out at least and foot of water, a wall of cider-blocks, and lead plate. But it's just I need a versital cheap power supply capable of fusion power, and pole transformers look perfect. And this could provide useful info for others. Anything is helpful.

,Andrew Hahn

Wilfried Heil
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Re: operating pole pigs

Post by Wilfried Heil » Wed Jan 11, 2006 2:17 am

I haven´t used a pole transformer yet, but I´m sure some here have - on Tesla coils.
The question about neon transformers comes up here regularly, but pole pigs ?!

It does not appear to be easy to combine high voltage and high current in a fusor. At least one University group (of two) has tried and failed dismally. I think to enhance fusion in the kW range, a more sophisticated means of ion generation would be needed, rather than more raw power.

I´m more and more doubtful on what the purpose of driving the fusor to new records can be. 100 kW at 50,000 V ?? If it were possible, it might give 100 million neutrons/s.

On the other hand, these would be easily available from a small DT neutron tube, consuming just 3-5 Watts. The fusor is highly inefficient as a neutron source. But it does make a couple of them.

I just decided not to buy a 4KW Glassman power supply on Ebay for the same reasons.

Todd Massure
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Re: operating pole pigs

Post by Todd Massure » Wed Jan 11, 2006 3:00 am

There was a discussion about pole pigs a while back. It should come up on a search.

DaveC
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Re: operating pole pigs

Post by DaveC » Wed Jan 11, 2006 6:34 am

A "pole pig", or a distribution voltage transformer, is a very respectable AC source, but also rather dangerous unless carefully operated with proper overload protection.

Their use for fusor and other experimental work, is covered somewhere in the various threads on this topic, at least.

One should not confuse a distribution class transformer with a neon sign or an oil burner ignition transformer... the pole pig is designed to have the smallest possible secondary voltage drop. They are very low output impedance devices... and could, if the source had the juice, pump very large amounts of current into a short circuit.

As Wilfried has already stated.... and I share the view, it is not clear that progress with a fusor comes from pumping in massive amounts of current at ever higher voltages. That will produce huge amounts of xrays, and maybe some higher neutron numbers, but that's it.

But, I would say if you can find a baby unit... 5 to 10 kva max, this would be all you need. Most distribution transformers are not even "working" hard until they are above 100% overload!. That's by design. But 12 - 16 kV at upwards of 20 amps or more, this is really a life threatening hazard, unless you know your way around electricity, and are dedicated to safety and your personal longevity. It's a big source.

That said, if you take it apart and rearrange or rewind the primary or secondary, you have the opportunity to learn about one of the real workhorses of the industry.

Just make sure what you get is certified as "PCB Free". It is not the hazard of PCBs that you should fear, but the problem of how to get the thing off your hands, without paying $$$$ if it is filled with Askarel or one of the other non-flammable older oils. And woe unto you if you spill some... on your property. Could have to have the HazMat folks come out and and test and bless... etc. Trouble no one needs.

Have fun, and be real careful...

Dave Cooper

Starfire
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Re: operating pole pigs

Post by Starfire » Wed Jan 11, 2006 9:47 am

I would urge extreme caution - if you have to ask about pole pigs then you are not trained nor experienced in there use and operating conditions but are attemping a fundimental design. Make one mistake and it will be your last. As Dave has said, they are low impedance devices and will produce extreme and lethal current on the secondary and if you are using it as a step-up, you will have the volts to deliver that current.

A short on the secondary ( in the step-up application ) will also draw a massive current on the input and most likely drop out the entire neighbourhood distribution and can take the fuse carriers of the wall. Ensure you have electrical fire extinguishers on hand.

An other point;- the cableing, current protection and physical hazard protection is on a different scale - the rectifying diodes need to capable of carrying 50amps at 20kv - they are brutes and need serious insulation on HV insulators and a barrier cage. The switching breakers are equally large. Lock-out protection is mandatory when working with this apparatus.

I have such a setup but find infrequent use for it also the transformer weighs a Ton and can only be moved on a heavy trolly. It can not be set up on the kitchen table and will require substantial dedicated ground area. It also requires adaquate third party protection and locked cage - neighbours don't appeciate you frying their kids.

Your last problem will be to get rid of the heat in the fusor if you run it for any period - 16kva in a small confinement will roast better than 2000*C Kiln.

A design using a pig should not be taken-on lightly but good luck if you do.

HighVoltageFox
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Re: operating pole pigs

Post by HighVoltageFox » Thu Jan 12, 2006 12:03 am

I will keep this all in mind. I am not really looking for efficiency as much as for fission rates. I want to experiment with irradiation of elements and compounds. If I do use a pole pig I will take no chances and contain everything off the HV side in oil and plastic, and make sure I am far away from the fusor and pole pig. As well will I use insulation on myself, rubber gloves, rubber shoes, and a rubber mat when working on the fusor or power supply. The fusor and power supply will be in seperate inclosed rooms too. I am not going to give it a chance to kill me; I don't take safety lightly when around electricity.

I completely forgot that I would probibly need to rewind the coils, so I should know their configuration. But could I use stacked diodes or would that techniqe not work for such high amperage.

,AH

Starfire
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Re: operating pole pigs

Post by Starfire » Thu Jan 12, 2006 10:47 am

Suitable diode doubliers work OK for high current Andrew, but the caps also have to be high value if you want a high current output. Your worst hazard as you up the voltage, will be xray's and with high current you will generated lethal dose's - serious xray shielding becomes a must, as is remote operation.

Too give you a better feel for it;-

My reactor experiment area has purpose built earth mound shielding over 2 mtrs in height above ground and 6mtrs long on three sides - the exposed side points to open fields. The site is over 100mtrs from nearest dwelling.
The 'tiny ' 0.05 mm reactor I am currently working with, is under a meter of water in a 2 meter deep pond and below ground level. In my design - I use only microgram reagents - but can punch 400+ joules at 22kv input power - I need apparatus cooling even for short duration pulse work. The control point is 25 mtrs beyond the mounds. I may have to install a generator even with my maximum power always well below 10kva, as the loading does impact severely on the domestic supply.

Like I said;- High Voltage High Current experimentation is a different ball game - it is some thing you will not do quickly and needs a lot of committed resources. I would suggest you start small - very good high quality work can be done with a small system.

If it all works and you produce large quantities ( gram qty ) of your required isotopes you will have a serious problem to dispose of the many undesireable long half-life and unwanted byproduct elements you are also likely to produce. I expect everything will be as hot as hell, including the apparatus. How to dismantle, handle and dispose of hot apparatus?

There are many unseen considerations with serious implications. Not to mention the legal aspects of producing, storing and holding such quantites of Radio-isotopes.

HighVoltageFox
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Re: operating pole pigs

Post by HighVoltageFox » Thu Jan 12, 2006 10:59 pm

Thanks for all the information.

,AH

Starfire
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Re: operating pole pigs

Post by Starfire » Fri Jan 13, 2006 9:38 pm

If you go ahead with it Andrew - give me an email - I have had both good and bad experience and may save you some grieve - also have built 10 amp 11kv doubliers and bridges hung on a pig - get a big variac - 10 amp plus - for the input - they are invaluable while building and give much needed control when you are running. But please be careful when powering.

I also have built a 20kv supply ( ideal for a start fusor ) from a microwave oven transformer and a few MOT diodes & caps, multipling up with several stages from a 2.5kv transformer - cheapest way to go, specially if you use scrapped ovens - if you can get the indrustrial type - they are much better and usually above 1kw.
Good luck.

3l
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Re: operating pole pigs

Post by 3l » Tue Jan 24, 2006 4:46 pm

Hi Guys:

BTDT:

See this post made a while back.
2004-19-01 09:46 Something new on pole pigs (larry leins) [Latest: 2004-19-01 14:35] (1)

Happy Fusoring!
Larry Leins
Fusor Tech

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