Search found 120 matches

by David D Speck MD
Sun Mar 24, 2013 9:14 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: cutting high voltage feed electrode
Replies: 3
Views: 1539

Re: cutting high voltage feed electrode

<t>As long as you don't damage the insulator, you should be OK. <br/> <br/> I would chuck the unwanted portion of the electrode in a metalworking lathe, and use a parting tool at very low speed, as close to the lathe chuck as practical, to make the cut. Be prepared to catch the rest of the feedthrou...
by David D Speck MD
Sun Mar 10, 2013 10:58 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: High Voltage Diode Testing Question
Replies: 10
Views: 5225

Re: High Voltage Diode Testing Question

That's OK, Chris,

Great minds do think alike!

Dave
by David D Speck MD
Sun Mar 10, 2013 10:50 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: High Voltage Diode Testing Question
Replies: 10
Views: 5225

Re: High Voltage Diode Testing Question

<t>Dennis,<br/> <br/> HV Diodes are made up of many series connected diodes of lower voltage ratings. They will look like an open circuit in either direction to an ordinary DVM. <br/> <br/> Whereas a single silicon diode has a typical forward voltage drop of 0.4 to 0.6 volts, a HV diode may have a f...
by David D Speck MD
Wed Mar 06, 2013 4:09 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Rectification for homemade supply
Replies: 4
Views: 1889

Re: Rectification for homemade supply

<t>Most fusion experimenters seem to agree that a filter cap is not required, though it seems more elegant to have one.<br/> <br/> Big problem is that a filter cap will have a lot of stored charge on it which can bite you hard if you are not extremely careful. If you put a bleeder resistor on it, it...
by David D Speck MD
Mon Mar 04, 2013 4:14 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Potential safety setup
Replies: 7
Views: 4113

Re: Potential safety setup

Justin,

What do you figure your total accelerating potentials will be? That will pretty much determine how much shielding you need.

Dave
by David D Speck MD
Wed Jan 30, 2013 6:35 pm
Forum: Fusion --- Past, Present, and Future
Topic: Limited Edition
Replies: 2
Views: 2530

Re: Limited Edition

James,

The file type of the attached file shows up as "Application/Octet stream".

My Win7 doesn't seem to know how to present it.

Might want to link it as a .JPG or something similar.

Dave
by David D Speck MD
Mon Jan 21, 2013 4:44 am
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Prototype reactor PS
Replies: 15
Views: 7090

Re: Prototype reactor PS

<t>Emanuel,<br/> <br/> Just be aware that, as is amply documented in this forum, a D-D fusion system that operates at even 1% of breakeven would produce a radiation flux rapidly fatal to the operator unless very heavily shielded. <br/> <br/> Be sure to get your shielding in place before you get to s...
by David D Speck MD
Sun Jan 13, 2013 3:53 pm
Forum: Vacuum Technology (& FAQs)
Topic: Edwards Active Inverted Magnetron information
Replies: 12
Views: 4373

Re: Edwards Active Inverted Magnetron information

<t>Andy,<br/> <br/> I think that for Jack's application, an Arduino would be plenty fast enough. Many typical industrial digital panel meters only update twice a second. High end meters might update 10 times a second.<br/> <br/> I would think that an Arduino could provide updates faster than you cou...
by David D Speck MD
Wed Jan 09, 2013 4:34 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Polarity Question.
Replies: 8
Views: 3106

Re: Polarity Question.

<t>Carl,<br/> <br/> The nameplate looks to me like it's 5 uF, not 500 nF. Either way, you will need to supply some sort of discharge mechanism to bleed off the considerable stored energy after you are done with your experiment. <br/> <br/> I would suggest a normally closed vacuum relay that connects...
by David D Speck MD
Tue Dec 25, 2012 12:25 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Using two NSTs..?
Replies: 1
Views: 811

Re: Using two NSTs..?

<t>John, <br/> <br/> You cannot series connect two NSTs for higher voltage because most of them have the center tap of their high voltage winding connected to ground. You can parallel them for more current, but this is rarely necessary in Fusor applications.<br/> <br/> The best you can get out of a ...