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Registered Member #3610
Joined: Thu Jan 13 2011, 03:29AM
Location: Seattle, WA
Posts: 506
He's used the bottom portion of a TO3 transistor with the glass insulated leads to pass electrical connections through the lid into a vessel that can be evacuated. It's deceptively difficult to do normally and proper passthroughs are expensive.
Registered Member #3414
Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245
Nah wrote ...
You really like pickles Adam
So, I feel a bit thick, could someone explain this?
Basically, he has re-invented the Edison light bulb, but it also has plenty of other uses., eg electrostatic grids, vacuum tubes (valves) etc.
Patrick wrote ...
I wonder if I could make these out of all-thread screw rod and Porcelain, maybe sell the spares here on the forum?
Usually the simplest way to do this is to use an automotive spark plug, inverted, so the long end is inside the chamber. You should also use an unsuppressed plug, eg a Ford Model T plug.
(I'm actually working on what you suggest. I've some 'cement' specifically for this purpose.)
Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4061
Handy for homemade fusors, etc.
Can someone PLEASE tell me where I can fund a decent vacuum pump for less than £50 which works well enough for basic demonstration of poissors etc (1 Torr or so?)
Registered Member #3414
Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245
Conundrum wrote ...
Handy for homemade fusors, etc.
Can someone PLEASE tell me where I can fund a decent vacuum pump for less than £50 which works well enough for basic demonstration of poissors etc (1000 Torr or so?)
Thanks.. -A
I've a couple of Edwards units, I may be persuaded to part with one, but it is belt drive and doesn't have a motor.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
Ash Small wrote ...
Patrick wrote ...
I wonder if I could make these out of all-thread screw rod and Porcelain, maybe sell the spares here on the forum?
Usually the simplest way to do this is to use an automotive spark plug, inverted, so the long end is inside the chamber. You should also use an unsuppressed plug, eg a Ford Model T plug.
(I'm actually working on what you suggest. I've some 'cement' specifically for this purpose.)
Yes but the light bulb and sparkplug are large diameter and long... if i need an array of terminals, then i could use all-thread and a pin-grid arrangement on a rectangular piece of porcelain. Both the porcelain and all-thread Would be custom demensioned easily.
Registered Member #193
Joined: Fri Feb 17 2006, 07:04AM
Location: sheffield
Posts: 1022
Conundrum wrote ...
Handy for homemade fusors, etc.
Can someone PLEASE tell me where I can fund a decent vacuum pump for less than £50 which works well enough for basic demonstration of poissors etc (1000 Torr or so?)
Thanks.. -A
You might want to check your units there. 1000 torr is a little over normal atmospheric pressure.
Registered Member #3414
Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245
Patrick wrote ...
Ash Small wrote ...
Patrick wrote ...
I wonder if I could make these out of all-thread screw rod and Porcelain, maybe sell the spares here on the forum?
Usually the simplest way to do this is to use an automotive spark plug, inverted, so the long end is inside the chamber. You should also use an unsuppressed plug, eg a Ford Model T plug.
(I'm actually working on what you suggest. I've some 'cement' specifically for this purpose.)
Yes but the light bulb and sparkplug are large diameter and long... if i need an array of terminals, then i could use all-thread and a pin-grid arrangement on a rectangular piece of porcelain. Both the porcelain and all-thread Would be custom demensioned easily.
A disc of porcelain may prove to be more suitable, depending on the application.
(EDIT: I'll post details of the 'cement' I have after I dig it out of the garage.)
Registered Member #3766
Joined: Sun Mar 20 2011, 05:39AM
Location:
Posts: 624
1000 torr is about 1.5 atm, 760 torr is 1atm. if you mean 100 torr, I have a venturi effect pump I got for like $15-20 that will go that low, it boils lukewarm water at room temperature when I put about 100PSI through it.
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MacGyver Vacuum feedthrough
