#4a FAQ - Wiring for real fusion fusor - part one

If you have a question about this topic, the answer is probably in here!
Post Reply
User avatar
Richard Hull
Moderator
Posts: 12181
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

#4a FAQ - Wiring for real fusion fusor - part one

Post by Richard Hull » Tue Mar 02, 2004 7:10 pm

This diagram is for a demo fusor using a 15kv neon sign transformer. However, the basic circuit shown can, with extra 100 meg resistors in series and modified voltage metering circuitry be tied to a large 40kv or greater grounded, center tapped power transformer. Such high voltage transformer types are found in electrical distribution transformers and potential transformers as well as the ocassional X-ray system transformer.

For a full blown fusing fusor system, X-ray transformers are best. A 60kv center tapped x-ray transformer can be expected to give a peak rectified voltage in this circuit of 30 X 1.414 = 42 kilovolts Which is just capable of getting up to 1 million neuts/sec in a well designed and operated fusor at 10 to 15ma. Note: With this higher voltage transformer example, the metering circuit would need more series 100 meg resistors and a different metering setup to read to over 40kv. The figuring of this voltage metering circuit is left to the individual.

Needless to say, such transformers are lethal and demand a massive 50amp 240 volt breaker box connection. They are unforgiving. One wrong step and you are dead. Of course, real fusion high voltage must be at least 25 kilovolts DC and this, in and of itself, is instantly lethal.

The 100 megohm resistor is best made up of 10, 10 megohm 1 watt 2% or better flame proof resistors, in series, floating in air between two posts on clean plexiglass. True 100 meg resistors, (hard to locate), can be used in series for larger voltages than 10kv. I prefer 0ne 100meg resistor in the voltmeter circuit for every 10kv of desired output.

You will note this same circuit "layout" can function for both a neon demo supply and a full blown fusing fusor system. The difference is that this circuit for higher voltage more powerful center tapped transformers would demand handmade diode strings and a suitable large 50-100 watt ballast resistor in series with the HV output line and the above mentioned metering changes.

Richard Hull
Attachments
meter hookup.jpg
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.

Cristiano_Machado
Posts: 37
Joined: Fri Aug 24, 2018 1:03 pm
Real name: Cristiano Machado
Location: São Paulo - Brazil

Re: #4a FAQ - Wiring for real fusion fusor - part one

Post by Cristiano_Machado » Sat Nov 17, 2018 6:33 pm

Dear Richard,

I know it's not appropriate to post doubts in faqs, please fell free to erase it, after answer.

I saw in your other post about "Measuring Fusor Voltage" viewtopic.php?f=29&t=4267 that you recommended using 100megaohms resistors for each 10 kV to be measured. In this post you recommended just one group of 100megaohms resistors and changed the panel meter.

I would like to know each setup is better (if any).

Thanks,

Cristiano

User avatar
Richard Hull
Moderator
Posts: 12181
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: #4a FAQ - Wiring for real fusion fusor - part one

Post by Richard Hull » Sat Nov 17, 2018 10:02 pm

You will notice the absolute limit in this schematic is only 10kv on the voltmeter. This assumed a 15kv neon sign transformer where the rectified voltage, wired as shown, would be only about 10kv. ( less under a demo fusor load) This circuit is much more suited to a demo fusor. 10kv max output.

However I use this exact circuit for my 40kv x-ray transformer but with 4 100meg resistors in series and and altered voltage metering system.

NOTE: the above resistor value of 100 megohms per 10kv to be measured in the diagram are for those using ONLY a 100ua meter movement!!!!!! example....8,300 volts would read 83ua on the meter shown.
If you wanted a 20kv meter using the 100ua meter movement, you would use 2 100 megohm resistors in series with the meter. If you do not remark the meter face, 15,000 volts would read 75ua on the meter.

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.

User avatar
Richard Hull
Moderator
Posts: 12181
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: #4a FAQ - Wiring for real fusion fusor - part one

Post by Richard Hull » Wed Jul 01, 2020 6:51 am

I have now posted a final update to the diagram with a bit of suggestion data on the current metering block below it red box in the diagram. I hope this and the subsequent reply postings clear any questions up.

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.

Post Reply