Search found 1648 matches

by Dennis P Brown
Sat Feb 16, 2019 2:54 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: X-ray transformer issues
Replies: 7
Views: 376

Re: X-ray transformer issues

Since surface tension and air being trapped deep in the coil are the main issues, simply "bumping" the item while it is under oil is not likely to remove these types of issues. Certainly it will help for bubbles on the x-former surface. I would suggest, in lieu of vacuum, heating the oil and transfo...
by Dennis P Brown
Sat Feb 16, 2019 12:45 pm
Forum: Fusor and/or General Fusion Theory (& FAQs)
Topic: Fusors and Maxwell's Equations
Replies: 6
Views: 1225

Re: Fusors and Maxwell's Equations

A few comments that may or may not help those that desire to build a demo fusor at a school - either a student or teacher. First and foremost, don't call a demo fusor project by that name. As soon as anyone in admin or safety googles that word, then nuclear fusion, neutrons and possibly x-rays sourc...
by Dennis P Brown
Fri Feb 15, 2019 10:50 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: NST issues
Replies: 15
Views: 489

Re: NST issues

Those pipe fittings will not provide as good a seal as proper vacuum components, so, not gong to be easy to seal the system to get good performance. Also, your valves are not likely to permit good vacuum performance at all.
by Dennis P Brown
Thu Feb 14, 2019 5:31 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: NST issues
Replies: 15
Views: 489

Re: NST issues

A NST can't power any real fusor even with a voltage multiplier. The frequency is far too small. I used that system to generate 100 kV for an ion gun using very large caps. I use a conventional high voltage transformer for my fusor. A few good things about a NST: a NST isn't likely to kill you if yo...
by Dennis P Brown
Thu Feb 14, 2019 5:08 pm
Forum: Vacuum Technology (& FAQs)
Topic: Cleaning/Repairing Edwards E2M5
Replies: 20
Views: 1180

Re: Cleaning/Repairing Edwards E2M5

Gauges can always mislead. So, confirming that it is accurate is very important. As for my pump, the dis-assembly of the actual internal vacuum pump assembly was done without a kit. I did damage a flat gasket but silicon sealant fixed that. I reused the o-rings but that could be hit or miss - one di...
by Dennis P Brown
Thu Feb 14, 2019 4:00 pm
Forum: Vacuum Technology (& FAQs)
Topic: Cleaning/Repairing Edwards E2M5
Replies: 20
Views: 1180

Re: Cleaning/Repairing Edwards E2M5

Sorry the pump is still making your oil so dirty. By the way, I can only see one pic when I open the link you included - a pic of your tools and teflon tape. Is there only that pic? You cleaned the inside case but did you dis-assemble the actual pump stages? I did this with my pump and cleaned it. T...
by Dennis P Brown
Thu Feb 14, 2019 10:49 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: NST issues
Replies: 15
Views: 489

Re: NST issues

Richard is correct - plywood conducts easily at those voltages. Again, since neither power nor high voltage is the issue for your experiment (I assume you just want a real, negative DC source), I again suggest you use just a single pole on the NST as a source and ground the other pole. I do this and...
by Dennis P Brown
Wed Feb 13, 2019 9:59 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: X-ray transformer issues
Replies: 7
Views: 376

Re: X-ray transformer issues

I have read here some people use a vacuum pump to remove air from the transformer winding/container before leaking in the required oil. In this manner the entire winding assembly gets filled with oil and no air is trapped. I have little experience with these devices so don't know if just submersion ...
by Dennis P Brown
Wed Feb 13, 2019 9:31 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: NST issues
Replies: 15
Views: 489

Re: NST issues

Since you are simply creating a DC plasma (your goal), then the best practice is to ground one terminal of the NST then use the 7.5 kV from the other (I do this with my NST.) The RMS is well under 15 kV now. However, one must remember that air and the diodes' surface can conduct 7.5 kV over the shor...
by Dennis P Brown
Wed Feb 13, 2019 9:19 pm
Forum: New User Chat Area
Topic: Some noob high voltage divider questions
Replies: 4
Views: 223

Re: Some noob high voltage divider questions

Since your chain of 100 m-ohm resisters are only 5% (so each can be +/- 250 k-ohms), these could either cancel (unlikely) or all add up the wrong way (also, not likely.) More likely, you will have a significant error of at least a few 100 k-ohms in the chain. In any case, these might create a bigger...