Search found 71 matches

by Finn Hammer
Fri Feb 02, 2018 8:11 pm
Forum: Images du Jour
Topic: Fusor progress, Finn Hammer
Replies: 25
Views: 7829

Re: Fusor progress, Finn Hammer

As I was walking around in the local recycling facility, also known as the scrapyard, my eyes glued themselves to a machine chassis sitting on the top of a 30 foot container, and I couldn't pass it up, because it was the perfect size. It is gross overkill, but I like that, and who can argue against ...
by Finn Hammer
Thu Jan 25, 2018 11:42 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Voltage multiplier help
Replies: 7
Views: 2884

Re: Voltage multiplier help

Bob,
Am I correct in assuming, that you do not have a feedback network to stabilize the output of your supply?
If yes, this is great news, since the feedback network design is a challenging task.

Cheers, Finn Hammer
by Finn Hammer
Thu Jan 25, 2018 7:14 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Has anyone used the Spellman X3000 50V-30kV 400uA Rev E7 24Vdc
Replies: 8
Views: 3675

Re: Has anyone used the Spellman X3000 50V-30kV 400uA Rev E7 24Vdc

Samuel, The supply you show is identical to the one I tested in this thread: http://www.fusor.net/board/viewtopic.php?f=11&t=11992&p=78210#p78210 It is a relatively simple design, but it does deliver the advertised voltage and current. Open circuit, it does not regulate down to zero volts. The outpu...
by Finn Hammer
Tue Jan 23, 2018 7:03 pm
Forum: Images du Jour
Topic: News from Argentina
Replies: 13
Views: 3823

Re: News from Argentina

Hi Jerry Good point, thanks! That one is 100 torr but we have also 10 torr FS. We will manage to put an elbow or swap positions with the viewport, now at cross lower port. Roberto, Please be aware,that the 10 torr FS unit puts out 1mV per Micron of pressure, so that you are at the very far edge of ...
by Finn Hammer
Wed Dec 27, 2017 10:34 am
Forum: Images du Jour
Topic: Wait, what? Tiny fusors? Not for me!
Replies: 43
Views: 12143

Re: Wait, what? Tiny fusors? Not for me!

When the voltage in a circuit exceeds 20 - 30kV, field control becomes a game changer, and the key word here is radius of curvature. Why is that? The object is to avoid flash over in the form of arcs, or discharges into the surrounding air in the form of corona. These things appear in the reverse or...
by Finn Hammer
Tue Dec 26, 2017 9:11 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Criticize my HV supply design
Replies: 26
Views: 8541

Re: Criticize my HV supply design

Silvio,

I use a paper laminated phenolic, due to it's superior surface tracking properties. G10 or FR4 would do fine too, I'm sure. Cotton laminated phenolic is the worst in this respect, so avoid it like the plague.

Nice work, and great overkill with that transformer.

Cheers, Finn Hammer
by Finn Hammer
Wed Dec 20, 2017 6:06 pm
Forum: Vacuum Technology (& FAQs)
Topic: An interface to the MKS 901P transducer
Replies: 14
Views: 5503

Re: An interface to the MKS 901P transducer

Bruce, I am glad you got the boards working, that pin reversal on the LED display was a nasty one. Regarding your choice of buss voltage, I had a similar issue, and also fried a Micro, or it's voltage regulator. That is why I recommended setting the common supply voltage to 9V, which is the minimum ...
by Finn Hammer
Wed Dec 06, 2017 1:58 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Test of Chinese Precipitator Supply
Replies: 8
Views: 3568

Re: Test of Chinese Precipitator Supply

Tom,

You don't need a variac with a supply of this type, in fact, it would just complicate matters if you try to start it up with a variac.
Just turn both potentiometers all the way counterclockwise, plug it in, and off you go!

Cheers, Finn Hammer
by Finn Hammer
Wed Nov 22, 2017 6:56 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Criticize my neutron detection setup
Replies: 18
Views: 5872

Re: Criticize my neutron detection setup

Silviu, One thing about your data puzzels me, because they are a couple orders of magnitude away from my own data. I seem to have an output in the 1-3 volt range, whereas your setup appears to output in the 10 - 30mV range. So you trigger in the low tens of millivolt, whereas I would be comfortable ...
by Finn Hammer
Tue Nov 21, 2017 9:37 pm
Forum: Images du Jour
Topic: Fusor progress, Finn Hammer
Replies: 25
Views: 7829

Re: Fusor progress, Finn Hammer

Richard, Silvio Thanks for your usefull input, it helps me to focus on what is possible and desirable, and to spot it on sight. I lowered the voltage to 1600V and suddenly the counts changed to this much more desirable profile: Notice the setting: 2µS / division. 2µs.png Much like the difference bet...