Pretty Light Fusor V2

For posts specifically relating to fusor design, construction, and operation.
Aidan_Lee-Calamera
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Re: Pretty Light Fusor V2

Post by Aidan_Lee-Calamera »

Doesn't the gauge need calibration though? An analog input is simple enough I thought I saw that it all needs to be calibrated. That gauge I did see an arduino build here for though so maybe I'll get that, couldn't find any around that price so thank you very much for finding that one.
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Liam David
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Re: Pretty Light Fusor V2

Post by Liam David »

I think you're mixing up two things here: (1) gauge calibration and (2) conversion from analog output to pressure.

The gauge calibration is how accurately the gauge measures pressure. It will drift over time but is usually not enough to be worried about. You might see a factor 2 difference in measured versus actual pressure, ignoring gas-type-dependent sensors for the moment. This may seem significant, and in some applications it is, but your case it is not. As long as both sensor elements are functioning, I would not worry about the calibration of a 901p, especially for your first go at things.

The conversion from analog measurement value to pressure is always given in the manual. Details for the 901p can be found on page 27 of the manual. An Arduino could easily measure the analog output signal, do the math, and then display the pressure to an LCD, for example, or send it to a computer for display.

I would do some more searching before pulling the trigger on the gauge I linked. It's an ok deal, but bear in mind that it has a VCR fitting.
JoeBallantyne
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Re: Pretty Light Fusor V2

Post by JoeBallantyne »

The gauge Liam linked to is an RS485 gauge with a two wire connection. That will likely be more complicated to get working than one of the RS232 3 wire connection gauges. Per the manual, if the second digit in the device model number is a 2, it is RS485, if it is a 1, then it is RS232. Something like a 11030 or 11040 or 21030 or 21040 is more like what you want. First two digits of 11 or 21 should be the least difficult to get connected to, both electrically, and vacuum wise.

You might offer this guy https://www.ebay.com/itm/196169055522 $40 each for 2 or 3, and hope that one of the DB15 connectors is repairable/useable. He might not take $40, but I would be surprised if he doesn't take $50. I would start at $40. Unless you want to ask him for devices with electrical connectors (DB15) that are not obviously mashed. In which case I would offer him $50 each for 2.

Joe.
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Liam David
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Re: Pretty Light Fusor V2

Post by Liam David »

Thanks for the additional info Joe.

Ebay is all about waiting for a good deal to pop up. The 901p selection seems to be mediocre right now. I'm sure good deals on other gauges exist, with some effort in searching.
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Dennis P Brown
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Re: Pretty Light Fusor V2

Post by Dennis P Brown »

If the price of a low end vacuum gauge is a deal breaker, how will you handle neutron detection? Or the power supply? A fusor, even using a good bit of DIY and lucky e-bay finds will dwarf the cost of a simple vacuum gauge. If your just playing with a small plasma device I get it. But do consider what your goals are - currently, you made a plasma. Will just a vacuum gauge get you where you want to be?
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Richard Hull
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Re: Pretty Light Fusor V2

Post by Richard Hull »

The answer to Denniss last question is NO! The vacuum gauge that is useful in fusor use is the tiniest tip of the fusion iceberg bobbing above a future sea of cash. the power supply and sufficient neutron detection capability tower over the cost of any vacuum gauge.

Baby steps will get anyone there on a low budget over a longer period of time. A good vacuum gauge is essential, sure, but just a beginning.

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
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Aidan_Lee-Calamera
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Real name: Aidan Lee-Calamera

Re: Pretty Light Fusor V2

Post by Aidan_Lee-Calamera »

Thank you all so much for the many responses, I am currently in the process of trying to find a hamfest/flea near me that would have a gauge, just in case.

In response to Dennis, I am not currently looking to get into measuring and putting Deuterium in it just yet. For now this is just a display piece to show off the plasma that can facilitate fusion (although as stated I'm not quite there and have MANY upgrades), not actually doing any fusion, hence the name of the thread "Pretty Light Fusor", that is all it is, a pretty light (for now).

Also thank you for the correction Liam I most definitely misunderstood something I read. Since that is the case this is a lot easier than I expected and could probably do this with any (good) gauge since I have done so much stuff arduinos for projects I have lost count, and from what little I have looked at the manual it seems as simple as doing a map for the analog voltage to the units I would need. Sending the serial commands may be a bit tricky but I may be able to bit bang it on arduino.
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