Search found 101 matches

by Maciek Szymanski
Sat Feb 20, 2021 7:50 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: 5kV multipurpose power supply
Replies: 1
Views: 252

5kV multipurpose power supply

For some time I was building a power supply for my garage fusor and other plasma experiments. This is a demo grade PSU based on the step up transformer from an old breakdown tester. I’ve bought the complete tester quite cheaply and scavenged the trafo, a very nice variable auto transformer and some ...
by Maciek Szymanski
Sat Feb 20, 2021 6:31 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: 60Hz, 22kV transformer
Replies: 2
Views: 141

Re: 60Hz, 22kV transformer

Unfortunately I don’t have even single shed full of HV power supplies, so probably I will end winding my own transformer. Regarding the voltage multiplying - I’m not planing any. I hope that magnetic assistance/ion sources will compensate for the low end performance of the planned PSU. And in the wo...
by Maciek Szymanski
Fri Feb 19, 2021 7:29 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: 60Hz, 22kV transformer
Replies: 2
Views: 141

60Hz, 22kV transformer

I’ve just assembled a HV power supply for demo fusor/general plasma experiments. This is 5kV supply based on the breakdown tester transformer. I’ll post the details when I’ll do the load measurements, so I can report the detailed performance. 1CCF5131-F36E-4EE3-AA21-AD9DFE40A320.jpeg The small 5kV s...
by Maciek Szymanski
Sat Feb 06, 2021 10:00 pm
Forum: Vacuum Technology (& FAQs)
Topic: Help me in my baby steps in the vacuum world.
Replies: 11
Views: 1073

Re: Help me in my baby steps in the vacuum world.

For first tests I would try any inexpensive industrial vacuum pump oil like Total Agritraite 68. Or this one: https://www.ebay.es/itm/ACEITE-BOMBA-VACIO-VACUUM-PUMP-OIL-SUNOCO-1000ml-REFRIGERACION/323956124731?hash=item4b6d4a2c3b:g:qRIAAOSwJ9VdrzkT Regardin the piston/rotary question - for me the sh...
by Maciek Szymanski
Sat Feb 06, 2021 10:15 am
Forum: Vacuum Technology (& FAQs)
Topic: Help me in my baby steps in the vacuum world.
Replies: 11
Views: 1073

Re: Help me in my baby steps in the vacuum world.

There are super expensive, very low vapor pressure oils offered by vacuum companies like Varian or Leybold. And a lot of generic vacuum pump oils for industrial use (milking, vacuum packaging, handling, HVAC). Until you don’t expected your pump to work on the limit of it’s performance (and this requ...
by Maciek Szymanski
Thu Feb 04, 2021 6:18 pm
Forum: Vacuum Technology (& FAQs)
Topic: Bell and whistles diffusion pump based vacuum system.
Replies: 28
Views: 3740

Re: Bell and whistles diffusion pump based vacuum system.

The oil is fresh DC704 and the whole system is cleaned and overhauled. I don’t believe this ultimate pressure, it seem to me as gauge fault. I’m using very similar system at work (same pumps and valves) and it routinely pumps down to 1e-6 mBar (7.5e-7 Torr) but it takes a bit longer.
by Maciek Szymanski
Thu Feb 04, 2021 6:11 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Extremally cheap HV feed through (if you have a lathe in hand)
Replies: 18
Views: 1496

Re: Extremally cheap HV feed through (if you have a lathe in hand)

It is what I expected from the power supply. It works perfectly at high pressures and low voltages. But at lower pressures the breakdown is to abrupt for the current control circuit to follow and triggers the overload protection. After adding the ballast resistor the operation is possible by startin...
by Maciek Szymanski
Wed Feb 03, 2021 8:52 pm
Forum: Vacuum Technology (& FAQs)
Topic: Bell and whistles diffusion pump based vacuum system.
Replies: 28
Views: 3740

Re: Bell and whistles diffusion pump based vacuum system.

I’ve finally replaced the faulty switches with the 5A old stock Russian ones. And today I’ve started the diffusion pump for the first time. It worked seamlessly pumping the chamber (the gate valve body blanked with a 100mm flange and a viewport) down below 1 micron in less than minute. But I was sur...
by Maciek Szymanski
Mon Feb 01, 2021 9:22 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Extremally cheap HV feed through (if you have a lathe in hand)
Replies: 18
Views: 1496

Re: Extremally cheap HV feed through (if you have a lathe in hand)

I’m not sure what kind of glass it was, but probably borosilicate. And regarding the resistor - I suppose that this HF switching Glassman PSU is much more “jumpy” than that this big, high inductance iron core you are using Richard. I had chance to buy a 125kV 3 phase X-ray transformer for much less ...
by Maciek Szymanski
Mon Feb 01, 2021 6:35 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Extremally cheap HV feed through (if you have a lathe in hand)
Replies: 18
Views: 1496

Re: Extremally cheap HV feed through (if you have a lathe in hand)

Today I’ve installed the 40kΩ 150W ballast resistor. It has improved the power supply operation - I was able to stabilize the discharge at 18kV 30mA at pressure 4 to 6e-3 mbar. Still it required lot of fiddling with controls, and before I’ve mastered the technique the electron beam heating has cause...