Search found 31 matches

by Duncan Wilkie
Sun Aug 19, 2018 7:27 pm
Forum: Vacuum Technology (& FAQs)
Topic: Debugging an Inficon PKR 251 Series Gauge
Replies: 3
Views: 685

Debugging an Inficon PKR 251 Series Gauge

So I got this gauge (2000+ new) for like $200 on eBay and I've been having some issues with it. I attached it directly to the output of my diff pump and pulled a vacuum through it with my backing pump, and got like 15 torr. The pump was very loud, so I assumed it was my shoddy job of re-using a conf...
by Duncan Wilkie
Sun May 13, 2018 10:31 pm
Forum: New User Chat Area
Topic: How Have You Guys Made Your Inner Grids?
Replies: 3
Views: 959

How Have You Guys Made Your Inner Grids?

Perhaps the best way to figure out my own construction issues is to ask how the pros do it. I haven't had much luck finding information on the weldability/brazeability of pure tungsten to itself and stainless on the internet, so I thought I'd ask how you guys constructed grids.
by Duncan Wilkie
Mon Feb 05, 2018 4:49 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: The Beginnings of a Fusor Electrical System
Replies: 59
Views: 14323

Re: The Beginnings of a Fusor Electrical System

I do still have questions about measuring current on my system. The FAQs are written for someone with a DC transformer, and I'm not really sure how to apply them for an AC rectified one. Also, how do I insulate the resistors and such for a current measuring system? I would assume that since one is d...
by Duncan Wilkie
Mon Feb 05, 2018 4:39 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: High voltage wire
Replies: 8
Views: 1661

Re: High voltage wire

I have a length of this wire, and it is indeed rated 40kv on the casing, however, there are only 7 22-30 gauge copper strands in the conductor. Here's a pic:
IMG_2585.JPG
Don't know whether this is suitable for fusion work, probably not for Tesla coils though due to tiny current capacity.
by Duncan Wilkie
Wed Jan 24, 2018 2:02 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: The Beginnings of a Fusor Electrical System
Replies: 59
Views: 14323

Re: The Beginnings of a Fusor Electrical System

I want to pull together here all I can gather from postings here and ask some final questions to close this discussion. Clearly from resistance measuring the 3 and 4 pins of my transformer are HV outputs and pin 8 was clearly a center tap. The inputs are where the contention lies. Richard Hull had s...
by Duncan Wilkie
Mon Jan 08, 2018 3:15 am
Forum: New User Chat Area
Topic: A Quick Question
Replies: 2
Views: 650

A Quick Question

Is Loctite 290 (or similar) acceptable on NPT at foreline pressures?
by Duncan Wilkie
Mon Jan 08, 2018 2:49 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: The Beginnings of a Fusor Electrical System
Replies: 59
Views: 14323

Re: The Beginnings of a Fusor Electrical System

I have a question regarding current metering. The schematic on the FAQ for a center-tapped transformer (here) shows grounding to a metal case. I don't have a metal case on my device. I assume I simply place it in the ground loop of my device, but can I do this with an ac transformer?
by Duncan Wilkie
Fri Dec 29, 2017 4:39 am
Forum: Images du Jour
Topic: My WIP Fusor
Replies: 1
Views: 795

My WIP Fusor

This is my vacuum system in its current form. At the moment I'm waiting on some friends to get back from vacation to help me weld and machine the chamber. My diff pump was picked up on eBay and seems to be in great condition. Still gonna give it a good scrub with a scotch-brite and a soak in acetone...
by Duncan Wilkie
Thu Dec 28, 2017 1:38 am
Forum: Vacuum Technology (& FAQs)
Topic: A Few Quick Vacuum Questions
Replies: 3
Views: 778

A Few Quick Vacuum Questions

Ok so I’m pretty close to having all the components of a working fusor on hand and had a few questions. 1: Can I use only a ball valve in the forline? It seems that flow rate doesn’t need to be controlled here. Would a valve for plumbing suffice or are there vacuum-rated ball valves? Also, how can I...
by Duncan Wilkie
Sun Aug 27, 2017 8:40 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: The Beginnings of a Fusor Electrical System
Replies: 59
Views: 14323

Re: The Beginnings of a Fusor Electrical System

The output voltage measured between pins 3 and 8 and between pins 4 and 8 was a very stable 400V at 1V input. Similar results were observed with the other primary. However, when jumpering them in parallel, there was only a 100V increase in voltage from the original 400. Jumpering in series yielded a...