Search found 48 matches

by John Myers
Thu Jan 04, 2018 9:57 pm
Forum: Books & References
Topic: SolveSpace CAD
Replies: 3
Views: 7314

Re: SolveSpace CAD

The major selling point would be that it's open source; for those who find that important.
by John Myers
Thu Jan 04, 2018 9:52 pm
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Electrometers and Picoammeters
Replies: 14
Views: 15613

Re: Electrometers and Picoammeters

Would be nice to make the rest of the circuit with op amps, for example, rather than endless carefully matched bipolars and passives everywhere.
You can use an op-amp or two to replace the analog backend since op-amp are just a packaged version of all that circuitry.
by John Myers
Thu Jan 04, 2018 5:22 am
Forum: Books & References
Topic: SolveSpace CAD
Replies: 3
Views: 7314

SolveSpace CAD

SolveSpace is a free and open source [GitHub] computer aided drawing program (CAD).
I haven't used it yet but it looks like it could be a good choice for modeling fusor's and ion guns.
by John Myers
Mon Dec 18, 2017 6:54 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Thoughts on backplanes and card cages.
Replies: 7
Views: 3348

Re: Thoughts on backplanes and card cages.

There are definitely a lot of choices for a backplane architecture.

VXI or PXI could be a good choice also.
Ones like uTCA and ATCA have lots of high speed lines on them making the chassis' and modules expensive.
by John Myers
Thu Dec 07, 2017 4:17 am
Forum: Images du Jour
Topic: A nice Surplus item to make a Neutron Detector Power Supply
Replies: 6
Views: 3707

Re: A nice Surplus item to make a Neutron Detector Power Supply

The vacuum tube is likely a thyratron. Do you see a part number? The trigger amplifier I got from an auction also has a thyratron, an inductor (though much smaller) and a cap at the output. I believe the cap and inductor are for creating the pulse shape when triggered from the thyratron. It looks li...
by John Myers
Thu Nov 16, 2017 5:13 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: 50kv Spellman PTV Power Supply Setup
Replies: 4
Views: 4038

Re: 50kv Spellman PTV Power Supply Setup

Wow, your making things more complicated then they need to be. Just follow figure 3.2 B which only needs two 20K potentiometer and two 100 ohm resisters. You don't even need an external supply (pin1). Like Silviu said, LED dimmers use PWM control or control the current output neither of which you wa...
by John Myers
Mon Nov 13, 2017 2:52 am
Forum: Images du Jour
Topic: Say hello to my little (HV) friends
Replies: 24
Views: 7776

Re: Say hello to my little (HV) friends

The inside of the spark gap transformer only had a transformer in it. It was already drained of oil.
I suppose the instructions on the case were for whatever system/unit it was part of.
IMG_20171112_154959203.jpg
Inside of spark Gap Transformer
by John Myers
Sun Nov 12, 2017 3:17 am
Forum: Images du Jour
Topic: Say hello to my little (HV) friends
Replies: 24
Views: 7776

Re: Say hello to my little (HV) friends

The thyratron had a little ceramic chipped away by the pins but it doesn't look deep enough to be a problem. ------------------------------------------------------------------------------------------------------------------------------------ I got this Xray transformer earlier in the year off of Cra...
by John Myers
Thu Nov 09, 2017 4:53 pm
Forum: Images du Jour
Topic: Say hello to my little (HV) friends
Replies: 24
Views: 7776

Re: Say hello to my little (HV) friends

That's good point. I was thinking along the lines of the vent tube being punctured/cracked.
The 'pins' you see are more of a terminal block that fit over the actual pin and have a set screw to attach to the pin. I'll remove it tonight and do a closer inspection.
by John Myers
Thu Nov 09, 2017 3:38 am
Forum: Images du Jour
Topic: Say hello to my little (HV) friends
Replies: 24
Views: 7776

Re: Say hello to my little (HV) friends

The HTR and RES pins were both a little bent. Luckily the vent port wasn't bent or the D2 magic could have leaked out. The device is heavy so I think people picking it up would end up pressing against the pins causing them to bend.