Search found 980 matches

by Rich Feldman
Sun Sep 23, 2018 10:51 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Operating three phase high voltage power supply on single phase power
Replies: 1
Views: 84

Re: Operating three phase high voltage power supply on single phase power

Sounds very similar to using VFD's (variable frequency motor drivers) with 3-phase inputs on single phase wall power. Jerry Biehler spoke up authoritatively when that subject was discussed here, maybe a year ago, for a vacuum pump application. I know that for some units, the manual identifies which ...
by Rich Feldman
Sun Sep 23, 2018 10:16 pm
Forum: New User Chat Area
Topic: Power Source Voltage Ripple Regulation
Replies: 5
Views: 318

Re: Power Source Voltage Ripple Regulation

What's wrong with voltage ripple? I would think that for the same average voltage, the more ripple the better. Based on people saying that increased voltage brings a more-than-proportional increase in fusion rate, and applying that instant by instant. Look up Greg Courville's (sp?) fusion reports he...
by Rich Feldman
Sat Sep 22, 2018 11:33 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Neon sign transformer power: a new look
Replies: 8
Views: 1489

Re: Neon sign transformer power: a new look

Haven't had much time for the next step: floatable digital milliammeter. As mentioned before, general purpose $3 digital multimeters are very limited for measuring AC. If we need an external rectifier, might as well opt for a whole package that's much smaller and more fun. It took just a few minutes...
by Rich Feldman
Tue Sep 18, 2018 4:29 pm
Forum: The Trading Post
Topic: Stuff for sale at Halted Supply in San Jose, California
Replies: 3
Views: 162

Re: Stuff for sale at Halted Supply in San Jose, California

Oh that's sad news, Ian, but does not come as a big surprise.
A recent bolt from the blue was announcement that whole Orchard Supply Hardware chain is closing.
by Rich Feldman
Tue Sep 11, 2018 11:32 pm
Forum: Images du Jour
Topic: My first plasma
Replies: 12
Views: 1020

Re: My first plasma

What if the chamber were lined with a non-structural metal screen that you can see through? For example, fine woven wire cloth like that in fuel filters. Or perforated sheet metal like in microwave oven doors. If the holes are small enough, and/or optical transparency low enough, ion beams and e-bea...
by Rich Feldman
Mon Sep 10, 2018 2:58 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Neon sign transformer power: a new look
Replies: 8
Views: 1489

Re: Neon sign transformer power: a new look

Yes, my tiny LED panel meters are from ebay for $2 or $3 each. Could have got some about the same for $7 at the flea market. The voltmeters are all 0 to +30 with three wires; negative power and negative V_in share a wire. The ammeters (in various ranges) have built-in shunts and four wires (two thin...
by Rich Feldman
Sun Sep 09, 2018 11:08 pm
Forum: Images du Jour
Topic: Sharing hamfest booty images
Replies: 27
Views: 5265

Re: Sharing hamfest booty images

Yes yes & yes. I was picky about the free meters, and at least one looked like it had radium paint. Haven't tried lighting up the funny little diode. The valve does have those face-seal connectors, including a metal dent protector under one of the plastic dust caps. The rectifier says JAN-249? (prob...
by Rich Feldman
Sun Sep 09, 2018 5:30 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Neon sign transformer power: a new look
Replies: 8
Views: 1489

Re: Neon sign transformer power: a new look

Here's a preview of a 100 mA AC/DC digital panel meter, put together much more quickly than the kilovoltmeter in OP. I hope it can serve on the high side of multi-kV circuits, like NST's and color TV sets, when put in a compact enclosure with an anti-corona shape. Other high side metering options in...
by Rich Feldman
Sun Sep 09, 2018 4:55 am
Forum: Images du Jour
Topic: Sharing hamfest booty images
Replies: 27
Views: 5265

Re: Sharing hamfest booty images

The electronics flea market in Sunnyvale (formerly Cupertino), CA ended its 2018 season today. Alas, demands of my day job left no time to pack up for selling. Double alas, I went anyway, and fell into binge mode. Brought home many things that are small and inexpensive, or small and free. Here are a...
by Rich Feldman
Thu Aug 30, 2018 2:14 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Neon sign transformer power: a new look
Replies: 8
Views: 1489

Re: Neon sign transformer power: a new look

Yes, what John said. Sorry about posting a chart without labeling the curves. This little transformer is responsible for first set of data from my lab. The device, and the method, are described a couple of posts ago. DSCN0803.JPG Core laminations have no joints on the outside perimeter. Looks like t...