Search found 251 matches

by Bob Reite
Fri Feb 09, 2018 10:28 pm
Forum: Fusion --- Past, Present, and Future
Topic: My Visit w Doug Coulter
Replies: 31
Views: 5872

Re: My Visit w Doug Coulter

I revisited David Kunkie post: I don't think that one could achieve a scaled back version of the "gonzo mode" by dropping the HV. My understanding from what has been reported is that Doug had rigged up his fusor as a power triode Armstrong oscillator. The oscillator was not only running at his desig...
by Bob Reite
Fri Feb 09, 2018 10:20 pm
Forum: The Trading Post
Topic: Super beefy HV insulator
Replies: 4
Views: 212

Re: Super beefy HV insulator (3)

It would depend on the process used to make the seal. If it was ceramic metallization and brazing, it would be limited to the melting point of the brazing alloy used, as low as 450 C if a soft solder alloy is used. Other seal methods can take temperatures up to 1000 C. Needless to say, I would not p...
by Bob Reite
Fri Feb 09, 2018 2:08 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: High voltage wire
Replies: 7
Views: 250

Re: High voltage wire

Yep, I've never seen a residence with a 600 amp service! When I lived on the west coast, I did encounter a resistance heated Bel Air mansion with a 400 amp service. It was built in the mid 1930's or so for Warner Baxter. Being a movie star, he could afford a big electric bill.
by Bob Reite
Fri Feb 09, 2018 1:27 am
Forum: Fusion --- Past, Present, and Future
Topic: My Visit w Doug Coulter
Replies: 31
Views: 5872

Re: My Visit w Doug Coulter

I would visit Doug's site at http://www.coultersmithing.com/forums/index.php for his latest news.
by Bob Reite
Thu Jan 25, 2018 1:27 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Voltage multiplier help
Replies: 7
Views: 296

Re: Voltage multiplier help

No feedback network. To get the two parallel amplifiers to share the load, there are 2 ohm 100 watt resistors in series. with the 100:1 turns ratio of the transformer, that makes the output impedance of the supply somewhat high eliminating the need for a ballast resistor on the output. The amplifier...
by Bob Reite
Thu Jan 25, 2018 8:04 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Voltage multiplier help
Replies: 7
Views: 296

Re: Voltage multiplier help

I think once you run the numbers for a 60Hz supply, you will NOT want to spend the money on the large HV capacitors! Plus they will store lots of really destructive energy. As stated, you will need some source of 20-30 KHz energy to feed a ferrite core transformer. 30 KHz allows you to use reasonabl...
by Bob Reite
Sat Jan 20, 2018 5:40 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Voltage multiplier help
Replies: 7
Views: 296

Re: Voltage multiplier help

I think you meant 10 mA. Google for "Full Wave CW Multiplier" for a schematic. Google for "Full wave cockcroft walton voltage multipler calculator" for a handy site that will help you choose capacitor sizes based on frequency and how good or bad you want regulation and ripple. Ripple is not a big co...
by Bob Reite
Sat Jan 06, 2018 3:16 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: A Bunch of Failures
Replies: 46
Views: 1455

Re: A Bunch of Failures

IMHO, a mechanical pump is doing well to get into the single digit micron range.
by Bob Reite
Tue Jan 02, 2018 12:00 am
Forum: Please Introduce Yourself
Topic: Happy New Year from the new guy!
Replies: 3
Views: 192

Re: Happy New Year from the new guy!

W6VYW de WB6YYZ. I kept my CA call when I moved to PA Extra class here, and *not* an "appliance operator", fix my own gear.
by Bob Reite
Fri Dec 08, 2017 9:23 pm
Forum: New User Chat Area
Topic: How dangerous are X rays?
Replies: 5
Views: 270

Re: How dangerous are X rays?

At 30 KV and 10 mA, X rays coming out the viewport is a major concern. When operating at that level, I was using a mirror to view the grid and standing at least 10 feet away from the machine out of line of sight from the viewport. At 50 KV and 8 mA, I was getting some X-ray backscatter from the view...