Potential Transformers

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Emma Black
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Potential Transformers

Post by Emma Black »

Hey all, I scored some potential transformers. They are surplus from a new biomass power plant and even though I only paid scrap prices, they turned out to be brand new with a full testing report. Maybe these are a bit over the top given the much smaller and smarter options now available.

For a fusor would these be ok ran at the 50Hz grid frequency or would I be better off increasing it to smooth things out? Obviously with suitable rectification , grounding ballast etc.

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Richard Hull
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Re: Potential Transformers

Post by Richard Hull »

If the voltage rating of the primaries is 33kv like it says, You have struck it rich!! These are even better than x-ray transformers! (no oil!)

Potential transformers operated in reverse are ideal and even though rated normally around 500-1000VA they will gladly supply 2-3X their rated power in regular use. I have used them extensively in my Tesla coil work and have about 5 hanging around the lab. The issue in filtering and can only be done once rectified by very high voltage capacitors to create stable DC at loads. You need not have stable DC for fusor use!!! Reduced performance can be had by suitable full-wave rectification!! This again demands some very expensive diodes.

Another key issue pops up here. The base plate on many of these transformers is grounded and the center tap of the high voltage side (the top terminals) is connected to the grounded plate. This is a big issue and creates all manner of issues for fusor use where safety grounding issues raises its nasty and deadly lethal head.

With 33kv out of the top terminals, you might only have 16.5kv from each to ground, ( bottom grounded plate.) You must ohm this out and report back to us here!!

Take an ohmeter and measure from each HV terminal to the metal plate if the readings are about the same, you have a center tapped ground to the base plate. If open (no ohmddic reading) you are in great shape. However, I bet you will get readings.

Do not proceed to use these without getting back to us! With their power rating they will kill instantly if not used in a proper manner!

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.
Emma Black
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Re: Potential Transformers

Post by Emma Black »

Hey Richard, thanks for the info.

I wondered about that to, as initially there was a bolt on the back which looked like it went right into the plastic. On closer inspection though, it doesn't, there is a weird hollow in the mounding.

Anyway I just went out and tested. Nothing, triple checked, they are not grounded to the baseplate :)
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Richard Hull
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Re: Potential Transformers

Post by Richard Hull »

Neither top bolt will be grounded to the base plate. There might be some high resistance to the base plate of a number of kilohms! As half of the secondary, (midpoint in the winding), might be grounded to the base plate. Example: Across the two high voltage terminals 70k ohms....One terminal to the base plate 35k ohms.

Only special transformers with only a single HV terminal have the bottom of the HV secondary winding grounded to the base plate. Example: 70k ohms to base plate.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
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Emma Black
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Re: Potential Transformers

Post by Emma Black »

Apologies, I meant theres no connection, not grounded! It's an open circuit between the baseplate and either top bots and 22k ohms between the two.
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Richard Hull
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Re: Potential Transformers

Post by Richard Hull »

If this is truly the case, you have a totally unground referenced HV winding. A four diode bridge of sufficient voltage will supply your fusor at full voltage on the 110 volt line with a peak voltage of 33X1.414 = 46,000 volts DC unfiltered at 100 HZ. You wound need to ground the positive output of the bridge to the plate and also electrical ground the plate, as well. This will make the negative of the bridge your hot fusion lead.

If you do this, take your bridge grounded system up to full voltage before you hook up the fusor. If your secondary is ground referenced, at least two of the diodes will explode! If no explosion you should be good to go.

HV knobs on potential transformers are traditionally ground referenced, (center tapped winding to ground). You have a rare beast.

As you acquired three at once, they may have been 3 phase types and could not be ground referenced in a leg.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.
Matt_Gibson
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Re: Potential Transformers

Post by Matt_Gibson »

I work for an electric utility and we have tons of these. I need to see if we have any 69kV ones that have just been sitting around needing to be taken off the books :-)

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Richard Hull
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Re: Potential Transformers

Post by Richard Hull »

Matt sounds like he understands. I always was amused at what the power companies call the primary, we call our secondary. The power company had them made up and due to the usage, they are correct. We are using them backwards and as such, the design in our use is not magnetically optimum, but they function great for our purposes.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.
Emma Black
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Re: Potential Transformers

Post by Emma Black »

Followed your suggestion Richard. Im pleased to report no diode explosions. After this, added a big resistor and threw together what I'm calling the "1 minute fusor". Will add the obvious that I didn't dare run this completely ungrounded wired safety nightmare of setup for more than a few seconds (at a distance) and the voltages were comparatively low.

Next step to wire up everything properly under oil with all the metering etc.

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Richard Hull
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Re: Potential Transformers

Post by Richard Hull »

That entire head is lethal! I sometimes am amazed at what is presented to me. 24 gauge clip leads can handle any current during normal fusor runs but act as fuses during any arc conditions. The 300 volt wire insulation adds to the illusion of the entire scenario of transporting and insulating up to 33 KV to the Hot feed thru gauge set. The gauge sitting at full high voltage does indeed show you have a vacuum of unknown pressure.

I love the "high tension" connection to the gauge set in the first photo, as well at the high voltage chamber standoff, cardboard box! Nice.

Nice kludge to get a glow discharge. A poster image for how to obtain the most lethal possible demo setup. It appears even the shell might be lethal. A nice example of a hands-on assembly of a hands-off demo fusor. The one positive is It works!


I am glad you realize the danger of what I see here.

As I tell all working with HV here.....Enjoy life, it may be short.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.
Matt_Gibson
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Re: Potential Transformers

Post by Matt_Gibson »

Looks like your PTs and your pump works….Now that you’ve been bitten by the bug (assuming?), work on a more safe and reliable setup. You’ll need better gauges and some reliable ways to measure voltage and current.

Focus on ease of operation over cost, it’ll be worth it! Trying to fuss around with difficult controls/locations and not trusting your values can take the joy out of things…

Think about safety (#1) and accuracy.

I think that the reason that most people seem to achieve fusion and then bounce is because they kludged everything together and operating their fusor became a chore.

-Matt
Emma Black
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Re: Potential Transformers

Post by Emma Black »

To be clear I am very aware this is a totally inappropriate setup for anything other than very nervously double checking if the transformer was centre tapped and this was not intended as a serious post.

The wiring etc is completely inadequate and dangerous for a vast number of reasons and probably more I can’t even think of!

I was many feet away with the variac on a long extension lead and unplugged the thing before going near it.

As for using borrowing my resin casting vac chamber I think the 1 minute setup included taking it off the shelf, kinda surprised it made any plasma to be honest.
Emma Black
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Re: Potential Transformers

Post by Emma Black »

As a follow up, ease of operation sounds like a good thing to focus on.

Operating a fusor fully manually from my reading so far and very limited experience seems similar to driving a Ford Model T, where you have to manage the spark gap, hand throttle etc. Friends uncle has one and it’s hard work but very satisfying once you get the hang of it.

I have been thinking about some slightly automated controls for further down the line, I.e. being able to adjust the voltage and gas flow digitally.
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Re: Potential Transformers

Post by Matt_Gibson »

Digital controls are nice, but you should focus on taking baby steps. Once you get a reliable and easy to operate setup, then you can start upgrading each sub assembly/system one at a time. Keep your eyes on eBay and snipe!
Emma Black
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Re: Potential Transformers

Post by Emma Black »

Totally, want to go super slowly this is a very long term project after all. First step is to make a lovely power supply.

EBay is dangerous for bank balances. I already scored a nice diffusion pump and one of the Ludlum 2363’s…
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Re: Potential Transformers

Post by Alex Aitken »

Should the pump have any extra grounding on account of low pressure gas sometimes being a good conductor?
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Richard Hull
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Re: Potential Transformers

Post by Richard Hull »

As an auto restorer in the 80's (50-60s Lincoln Continentals), it is rare to hear someone speak to the model T, especially the need to work the spark advance lever to adjust as you drive. Later taken care of in the distributor's auto-vacuum advance.

If you stick with the fusor effort, you will learn that same feel for operation that is pretty cool once you master it, just like the model T.

For Alex...Yes, all pumps and electronics need to have a common ground to the home electrical system.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.
Emma Black
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Re: Potential Transformers

Post by Emma Black »

Bit of an update, the bridge, big resistors etc have now gone into a nice neat box, with the PT output running though conduit all oil filled. Its vented and we will see how warm it gets.

People talk about mentioning the failures so I will mention my idiotic moment.

Before filling with oil I tested it dry, all good no issues at lowish voltage. One solder joint, right at the bottom looked a bit dry though so added some more solder . Without thinking poured the oil in immediately without letting the joint cool down.
Once the oil was in, suddenly nothing worked. The joint had cracked and wire had somehow come completely off. After a lovely mess of oil to cleanup later and we are back in business. I think crimp next time.

Next job, route the HV line through some pipes and put everything in one of the server racks I've liberated from a data centre decom

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Richard Hull
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Re: Potential Transformers

Post by Richard Hull »

Got enough oil for that diff pump? Looks like it could pump down a school bus interior. 14-16-inch throat?

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.
Emma Black
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Re: Potential Transformers

Post by Emma Black »

I know it’s massive (iso160) going to need a serious reducer - have enough dc704 to fill it once at the minute.
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Re: Potential Transformers

Post by John Futter »

that pump looks like a 1000/l/s edwards diff stack
more than adequate. To get full pumping speed out of it it requires an Edwards RV18 backing pump
I used two of these pumps on my 120kV ion implanter i built @ work
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Emma Black
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Re: Potential Transformers

Post by Emma Black »

Wow! Thats an amazing setup. Pump is a 700c & lucky have an Edwards 18, need to figure out the cooling etc.
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Re: Potential Transformers

Post by Luca Aldridge »

Where did you find those high end pumps?
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Emma Black
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Re: Potential Transformers

Post by Emma Black »

Backing pump was from Ebay, luckily in great condition, all the seals etc are new.

Diffstac was actually free though a friends work, along with a bunch of chemistry bits and pieces. Amusingly, the last PAT test sticker on the pump dates from 1998 so it had likely been sat in a cupboard for 20+ years.
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Re: Potential Transformers

Post by Luca Aldridge »

As seems the same with my diffstak 63. I sent the jet stack to get bead blasted and picking up tomorrow, hopefully the pump is in working order!
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Emma Black
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Re: Potential Transformers

Post by Emma Black »

The element on my diffusion pump seems to have issues, it trips the RCD after a few seconds. The manual suggests baking it in an oven for 8 hours at 180c to remove moisture, so we shall see how that goes.
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Re: Potential Transformers

Post by Luca Aldridge »

Good luck!
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Re: Potential Transformers

Post by Aidan_Roy »

Emma,

I had the same issue with my pump when first purchased. A good hot day in the sun insulated with fiberglass got er going again as I baked it out running on a 30 amp fuse. Once you get the water out of there, assuming its not a real short somewhere, all should be smooth sailing. Good luck!

Aidan
Emma Black
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Re: Potential Transformers

Post by Emma Black »

I tried it via a variac at half voltage for an hour, which seemed to do the trick. It can run for a couple of hours on full power now and seem to be getting a pretty decent vacuum already.

Chamber can take 40kV+ quite happily without any visible plasma or current draw. Now on to adding some gas back in!
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Dennis P Brown
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Re: Potential Transformers

Post by Dennis P Brown »

While a proper vacuum gauge will aid you far better, certainly when you get below 5 microns, plasma's do not occur. So you are achieving at least that level but without a high vac gauge, you will be in the dark to both the units real performance and ultimate vacuum - also, leak or out gas issues. Still, a good start. Be careful not to 'crack' the oil from any minor leaks (oxygen) or too high a temp (too much current draw or poor water flow.)
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Re: Potential Transformers

Post by Emma Black »

I have a pirani gauge, which at the lowest point is saying 0.37 microns (from the voltage I’m reading). However this was an untested eBay purchase and so could be a mile out of calibration.
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Re: Potential Transformers

Post by Luca Aldridge »

If you have another gauge, try and see how they compare. I think Justin has sone Edwards Pirani Gauges, but check with him first.
I'm testing my diff pumps tomorrow, excited to see how that goes.
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Dennis P Brown
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Re: Potential Transformers

Post by Dennis P Brown »

Once you get below 1 micron, (and you might even be in the 10^-5 torr or lower range) any pirani gauge might default to a non-zero but near zero value - much as you are reading. You will need a proper high vac gauge that handles 10^-5 and lower.
Emma Black
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Re: Potential Transformers

Post by Emma Black »

So even after an a few hours of pumping today the voltage, out of the gauge did not change at all, so either there is a constant pressure leak or more likely the gauge is bottoming out. Either way I have a freshly calibrated penning gauge on the way, hopefully good for 1 times 10 to the minus plenty. Apologies - this thread had wandered off high voltage discussions somewhat.
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Re: Potential Transformers

Post by Dennis P Brown »

We all do but since its your thread, and the primary topic is still relevant, no problem. Take it where you think most appropriate.
Emma Black
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Re: Potential Transformers

Post by Emma Black »

Some progress. After around 30 mins after the diff pump got up to temp I indeed got below 10^-5 torr, very pleased. After another 40 minutes it very slowly dropped a little lower This is the first long pump down and to be honest I wasn't particularly meticulous with the chamber cleaning, so there must be a fair amount of off gassing, but its looking good so far.

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Re: Potential Transformers

Post by Dennis P Brown »

Congrats! No surprise with that massive DP. In the future, one can keep their fusor super clean by leaving it under vacuum and not opening it. Of course, one can't have a real leak - then this method doesn't work. I know that for a new system, it is impossible to do this when one first starts using a fusor - many add on's after the fact, and adjustments to make that require opening the system. But once things get settled, that is essential for a good operating system. I can turn my fusor on, set the gas flow & voltage and that's it. It is stable for the entire time of the runs I make (i.e. my tolerance to run the system till the cathode heats up too much - say fifteen to twenty or so minutes.)
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Re: Potential Transformers

Post by Emma Black »

Yeah I need to open it again this week, to add the adaptor for the deuterium inlet, so I think thats where a deep clean with be useful. Also I reused a couple of con-flat gaskets from before, which if i have a leak will be the source, so have a brand new set to install. Really not a million miles away from letting some gas in and getting used to operating the thing before moving onto deuterium, considering I was aiming for the end of the year.

Way further down the line, assuming I get things working with a modest flux, I'm quite interested in exploring chamber cooling & even pre-heating in relating to wall loading effects.
To that end and some may hate this idea, but considering a fully submerged tank design that can be heated or cooled as needed to a precise temperature.
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Re: Potential Transformers

Post by Liam David »

I think that a deep clean will make a disproportionate difference when you attempt fusion later on. Hydrocarbons are evil.

You can get away with reusing copper gaskets if you tighten the flange only part way the first time, leaving a gap of a millimeter or so. On the second assembly, tighten until the flanges meet. Just keep it clean and the orientation unchanged between uses. I've had many such gaskets hit 1e-6 and two on my current system that is in the low e-9 without issue. Others here have had similar successes. The cost of new gaskets can add up fast, especially for larger flanges.

Submerging the device in a tank is not as crazy as some here make it out to be. It would make determining the absolute yield a little more challenging, but the cooling potential and moderation would be hard to beat. Don't forget about galvanic corrosion in conductive liquids, if you go that route.
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Richard Hull
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Re: Potential Transformers

Post by Richard Hull »

I have mused over the fully submerged fusor idea. So this is not a folly, but would demand a number of extreme measures. The beauty is water is a great moderator for scattering neutrons. All you would need is to sink the neutron detector underwater! (A very easy task as I used a water summerged 3He tube in a tank as my neutron moderator and detection system from 2003-2019)

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Emma Black
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Re: Potential Transformers

Post by Emma Black »

I'm glad it's not a completely crazy idea, although its a long way off. As you said light water with total coverage would make for a nice moderator. You could potentially use it for the diff pump cooling reservoir as well, with a chiller.

In my head I'm picturing a thick polycarbonate tank, reinforced with a metal frame, an extended feedthrough sticking out the water, a large diameter dump type valve so you can get rid of the water quickly if needed, plus lots of other measures to deal with catastrophes.

Question are some 3He tubes temperature sensitive?

Also - I did some cleaning on the chamber today and found that two bolts on of the conflats was only finger tight - opes. This plus the clean has improved the vacuum further. I used a hairdryer on the chamber to gently warm it up with the idea of speeding up the off-gassing. It was quite surprising how little heat it took for the gauge to start to climb.
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Re: Potential Transformers

Post by Matt_Gibson »

I wonder if (instead of a tank of water) we could use a stream/s of water with a catch pan underneath?

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Re: Potential Transformers

Post by Liam David »

I think if you go through the hassle of making a catch-pan system, ensuring that the falling water cools everything properly and routing numerous tubes, you might as well submerge it. I'd rather have a quasi-static tank system than a source of splashing. Also, without turbulent mixing that is supported in a container, your heat transfer coefficient will suffer.

3He tubes are almost entirely temperature independent. Since the volume is constant, the gas density and hence macroscopic cross-section remain unaffected. I've never so much as seen a response vs. temperature curve.

It takes very little temperature shift to affect the partial pressures of things. For example, the night vs. day pressure difference for my system is ~4e-9 vs. ~8e-9, albeit I live in a desert so it gets quite toasty in a garage. Now think what plasma bombardment and heating would do to outgassing, and you start to see why contamination can be a major inhibitor... Thorough cleaning and bakeout are necessary if you want to get the extra mile out of your system later on.
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Re: Potential Transformers

Post by Richard Hull »

Heavy gauge PE water tanks are readily available. They are found in farm supply stores. They are used as water troughs, water tanks, etc. They need no re-enforcement against the water pressure. The walls are designed to support the internal load of water against the walls.

There are also PE sinks like laundry sinks, etc. I think a suitable fusor friendly PE tank could be easily located as a stock, relatively low cost item of commerce. It would just take a search by someone interested enough to follow up on the concept of a submerged fusor system.

https://www.google.com/search?q=Farm+us ... e&ie=UTF-8

Local Northern Tool and Equipment stores might just have the ticket here

https://www.northerntool.com/shop/tools ... lsrc=aw.ds

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Emma Black
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Re: Potential Transformers

Post by Emma Black »

I was thinking about the farm tanks as well, there are about 30 of them currently stacked at the farm next to us. Other option would be custom aquarium type of thing. I have made several out of glass as well as plastic for fish and are fairly easy to do, obviously much smaller water mass and less access etc.

If the concept proves useful and something permanent is wanted, a below ground indoor pond type of thing, using a liner, would be cool. The water couldn't flood the lab and you could have a huge volume. Be fairly cheap other than the manual labour involved.
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Re: Potential Transformers

Post by Dennis P Brown »

Why not wrap the chamber using flexible copper tubing and conductive epoxy every few centimeters? I did this with a previous chamber and it worked great. You could even use a fluro-based coolant to get extremely low temps and much higher room temps using a simple compressor system. I did this in college for a cold trap for a DP (of course, the heated side was fan cooled.) Extremely safe and getting a old refrigerator (or a new window unit) can be done rather cheaply. Modification is trivial (even the old Sci. Am. Amateur Scientist discuses converting these units for cooling. Adding a heating feature is simple as well.)
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Re: Potential Transformers

Post by Emma Black »

I like that idea a lot, way less hassle - plus all the materials are on hand.

In other news, after a re-configure did another deep clean today and did a long pump out, hitting 3x10-6 torr quickly now. Then experimented with adding some argon back in, fair amount of learning needed to get the throttle the diff pump, gas inlet valve and the voltage right.

Did detected my first x-ray emissions to, wow they really stream out of the viewport! With the thick tempered glass server rack door closed however, it drops the rate right down as you would expect.
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Re: Potential Transformers

Post by Richard Hull »

Yes jockeying the valves to achieve a stasis in gas, versus voltage and current in part of the long touted artifice that exceeds the science and trains the mind and hands.

In many FAQs on radiation. The viewport is the killer orifice. Point it away from all living things. Above 35kv the entire device goes somewhat transparent to the high energy x-ray spectrum.

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Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.
Emma Black
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Re: Potential Transformers

Post by Emma Black »

I may attempt some xray photographs using some large format film I have, not of anything alive obviously.

As often is the case though, two steps forward and one step back.

One (or maybe all now) of my cheap diodes from China seem to have blown. The PT is now trying to draw huge currents on its primary as the variac voltage is increased, without the fusor even connected.
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Dennis P Brown
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Re: Potential Transformers

Post by Dennis P Brown »

I lost one (pair) of my diodes in my bridge a few months back (after over ten years of on/off operation) - and like your occurrence it was to the ground side. Never expected diodes so inexpensive to be all that good so I got extra when I ordered them the first time. Stuff happens.

Since my fusor's power supply can't go above 31 kV (generally 29-30 kV), I have never been able to measure any x-rays (even from the port window.) That all said, I still use a thick ceramic shield between me and the fusor to play it safe.

Once the chamber is truly clean, operation of a fusor can become nearly automatic and highly stable (assuming no leaks.)

In my case, once I start my mechanical pump, and turbo I pump my system down. Then I mostly close the turbo's gate valve. Next, open the deuterium leak valve four turns (discovered from past operation to be almost the exact value needed every time) and check the system's pressure. Next I slowly raise the voltage and somewhere between 19 kV and 28 kV strike a plasma. Then I use very small changes in the leak valve to set the desired current at the voltage I want to operate at.

I recently experimented and discovered that once I pull the system below 10^-4 torr (I have a fairly large chamber; KF seals), I can turn off the turbo and operate the fusor for decent periods of time (15 minutes to date; likely longer but have no reason to do that yet) - and the mechanical pump alone holds the proper pressure in the system. Apparently, my system is leak tight and outgassing is mostly deuterium from the wall loading.

So making the fusor leak tight offers a lot of advantages - such as stable operation being the primary one. Known, repeatable settings being another. No runaway current issues to deal with that hurts the power supply is nice. Finally, the fusor becomes the least concern in your set up and then one can focus on other issues/projects* for the fusor.

*And this can be both a good and a bad situation, too. As I've discovered by increasing my objectives - that is, doing other ideas/projects that others here have mastered can be a challenge. This is because one then discovers there are vast areas one needs to understand and learn that dwarf simple fusor issues. This in turns creates all new types of problems to tackle - these can be both fun and frustrating. Thank goodness for this forum and experts like Richard who has the patience to deal with people like me asking these questions.
Emma Black
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Re: Potential Transformers

Post by Emma Black »

Glad its not just me that has managed to pop some of them. I also bought a big pack so its no big deal, other than the usual fun of fishing things out of the oil.

Surprised you didn't detect x rays, how thick is the viewport glass? I was only running things at 20kv and the pocket sized GMC300E showed 2k cpm (fixed via electrical tape to the thin viewport).

I will have a quick go with the photography when I get things back up and running, its normal film but I have a small intensifier plate so figure putting both in a dark bag and inside the server rack door for a few minutes may make an interesting image. Friend of mine does xray photography on oil rigs off the coast of Scotland for pipe inspections, climbing off the side via rope access with a caesium source, he is fearless.

But yes the second cleaning helped a ton, I also really torqued down the bolts on the cf fittings and so far seems to be nice and stable in terms of pressure.
Emma Black
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Re: Potential Transformers

Post by Emma Black »

I also would like to add that this forum is an amazing resource with a huge depth of information available. So a massive thanks to all who have taken the time to answer some of my slightly silly questions.
Emma Black
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Re: Potential Transformers

Post by Emma Black »

Bit of an update, the bridge is now repaired and back in operation with extra diodes for safety.

The various controls and gauges have now also been moved into a new unit as things were starting to get a bit messy, voltage is still being read via a HV probe, so thats a job for another day. The grid has now been swapped for a tungsten carbide ring (stalk all smoothed down since the photo) and a new leak valve is nearly ready to be used, awaiting on some fittings and proper testing, but I'm pleased with the progress.


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Richard Hull
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Re: Potential Transformers

Post by Richard Hull »

If it is in good shape you will come to love that leak valve. You will need to mount it hard and fast for best use.

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Emma Black
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Re: Potential Transformers

Post by Emma Black »

Hey Richard, that photo is very useful, on paper these valves look very good.

It seems to work nicely so far for letting small amounts of gas in the control seems very fine, which hopefully means the sapphire is not cracked. I'm only able to test at deeper vacuum ranges at the moment though as my priani gauge seems to have developed a fault, which I need to look at.

The other valve option I potentially have is one of these, with the controller, but lacking the manual and specs its going to take a bit of experimentation to figure out plus the leak valve is likely better anyway.

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