Liquid diodes! - Page 1
Forum section: electronics / general

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 05, 2023, 11:31:04 pm
content: I never heard about this, I'll save some lead for emergencies!

author: Infraviolet
author_rank: Super Contributor
timestamp: September 05, 2023, 11:59:16 pm
content: There was another type of liquid diode too, used mercury held at a temperature where it was on the verge of evaporating. Its ability to rectify, and this was for distribution and railway level AC, not low voltages or 240V, depended on some sort of asymmetry in the direction that mercury gas and liquid droplets would move under applied voltages, might have been related to ionisation of them.

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 06, 2023, 12:56:38 am
content: Yeah I know mercury arc rectifiers

author: Stray Electron
author_rank: Super Contributor
timestamp: September 06, 2023, 01:06:30 am
content: Quote from: DavidAlfa on September 06, 2023, 12:56:38 amThe early ones used large,openpools of mercury! I have pictures around here somewhere.

author: amyk
author_rank: Super Contributor
timestamp: September 07, 2023, 02:47:27 am
content: I remember reading about something similar in an old book of electricity, but it was using a copper sulphate(?) solution. I can't seem to find that book at the moment but I did find this:On the Theory of the Electrolytic Rectifier (1902):https://ia800708.us.archive.org/view_archive.php?archive=/22/items/crossref-pre-1909-scholarly-works/10.1103%252Fphysrevseriesi.10.116.zip&file=10.1103%252Fphysrevseriesi.15.327.pdf

author: TimFox
author_rank: Super Contributor
timestamp: September 07, 2023, 03:35:13 am
content: The pioneer R A Fessenden built electrolytic detectors (diodes) with a wire in a liquid bath.He is credited with the first AM broadcast, and a diode detector was necessary (a coherer would be useless on AM).https://en.wikipedia.org/wiki/Electrolytic_detector

author: AVGresponding
author_rank: Super Contributor
timestamp: September 07, 2023, 08:19:17 am
content: Quote from: Stray Electron on September 06, 2023, 01:06:30 amPhotonicinductionhas a couple of vids:

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 07, 2023, 08:33:08 am
content: Quote from: Stray Electron on September 06, 2023, 01:06:30 amIt would be such a mess! Where did all the evaporated mercury condense?Not to mention the terrible health consequences if exposed to the vapours.

author: tom66
author_rank: Super Contributor
timestamp: September 07, 2023, 11:03:21 am
content: Flames can also be used to rectify current. This is used to effect in most modern home gas boilers to detect the presence of the flame, since carbonisation would create a parallel path, but only the flame creates a conductive path that works in one direction. I believe low voltage AC is passed through the rectifier and a detection circuit (or more likely a microcontroller nowadays) is used to isolate the gas supply if ignition fails.

author: coppice
author_rank: Super Contributor
timestamp: September 07, 2023, 11:48:55 am
content: Quote from: Stray Electron on September 06, 2023, 01:06:30 amI've never seen an open one, and I don't know how that would work. All that oxygen is going to cause trouble. I believe they are usually filled with an inert gas, rather than evacuated, because the glass envelopes are not that thick.

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 07, 2023, 12:36:36 pm
content: Quote from: tom66 on September 07, 2023, 11:03:21 amI knew flames conducted electricity, but not they rectified it!

author: amyk
author_rank: Super Contributor
timestamp: September 07, 2023, 01:41:13 pm
content: Quote from: DavidAlfa on September 07, 2023, 12:36:36 pmI'm not very familiar with the physics, but I suspect the effect is similar to a vacuum diode.

author: BrokenYugo
author_rank: Super Contributor
timestamp: September 07, 2023, 02:57:38 pm
content: Quote from: DavidAlfa on September 07, 2023, 12:36:36 pmYou can apparently even insert a grid and make a triode, interesting stuff. There are some vids on YouTube from a few different people if you look around.Some good reading here.http://www.sparkbangbuzz.com/flame-amp/flameamp.htm

author: coppice
author_rank: Super Contributor
timestamp: September 07, 2023, 03:24:45 pm
content: Quote from: amyk on September 07, 2023, 01:41:13 pmYeah. A vacuum diode makes a cloud of electrons. A flame makes a cloud of ions. They are all charged particles, which will only drift in a particular direction in an electric field. As someone else said, you can use a grid to make a triode from a flame. You can also put plates around the flame and wiggle the ions with an audio signal, making a loudspeaker.

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 08, 2023, 04:27:27 am
content: In the end it's just polarized dark fluid.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: September 10, 2023, 02:41:22 am
content: Uh oh, it's that time of year I post this linkhttp://www-smirc.stanford.edu/papers/chapter1.pdf

author: Dacian
author_rank: Contributor
timestamp: September 10, 2023, 03:21:11 am
content: I recognize that face in the video. Free energy and perpetuum mobile type stuff.Not sure why anyone will watch that channel.

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 10, 2023, 08:45:06 am
content: You're very wrong!He makes a lot of videos of rare mechanisms and engineering stuff, not that kind of BS.