Current direction?

[mhuss]

Which tube point do you not agree with? Mine or gearhead's?

Actually I was seconding Larry's point:

And yes - in tubes there's definitely a electron flow from the cathode to the plate, which is literally absorbing the electrons.

In fact, the only reason for the complex cathode coating chemistry is so it can emit as many electrons as possible.

--mark

[jaysg]

I have these vague recollections about all of this:

Benjamin Franklin was the idiot who decided that the electron would have negative charge.

In conductors and semiconductors, electrons don't actually flow. It's more like they wiggle and are not stripped away from their nucleus's.

[titanicslim]

Sorry, Jay, but I'm gonna gird up my loins to challenge your use of the word "idiot" there. Any portly septuagenarian with a schnoz like that who can attract that much high-grade French nookie definitely gets to say which way the invisible bits flow.

[mooreamps]

Just to make matters worst, let me add that under normal circunstances, NO electrons actually go THROUGH a tube (same for a capacitor!). These electrons has to come from a solid contact. FYI.

Yes, they do ! As one of the orginal contributors to the NEETS, I thought we made this one clear. If not, read the article on Edisons light bulb, when it became the worlds first vacuum tube diode.
-g

[mooreamps]

I have these vague recollections about all of this:

Benjamin Franklin was the idiot who decided that the election would have negative charge.

In conductors and semiconductors, electrons don't actually flow. It's more like they wiggle and are not stripped away from their nucleus's.

Yes, they do. An electron will leave the orbit of one nucleus and travel to another. This is covered in basic radio frequency antenna theory, where we can measure the amount of current feeding a transmitting antenna.
-g

[Jack]

I have these vague recollections about all of this:

Benjamin Franklin was the idiot who decided that the election would have negative charge.

In conductors and semiconductors, electrons don't actually flow. It's more like they wiggle and are not stripped away from their nucleus's.

Yes, they do. An electron will leave the orbit of one nucleus and travel to another. This is covered in basic radio frequency antenna theory, where we can measure the amount of current feeding a transmitting antenna.
-g

Ahem... No. Well yes and no. They do leave their orbits. In a metal and in a semi conductor, conduction electrons are delocalized. It's the so-called "plum-pudding" model in a sense. But it's not covered by RF antenna theory but solid states physics.

With any AC signals, Jay is right: the electrons do not actually move, they "wigle". They DO move when DC current is involved.

Actually, each individual electron move at a speed neighbooring the speed of light (~ 10^7 cm/s in some metals). And on average, they do so in ALL directions. But they collide with the atoms (which is responisible for the resistivity in a metal). When no voltage is applied, the electrons moves around like crazy at ~10^7 cm/s but on average "run around in circles" (they do not "move"). When you apply a current, they "run around in circles" around a center that slowly drift at the speed of the current (a few meters per seconds IIRC. I think you could walk as fast as the drift current. That drift current is the actual current that goes into ohm's law).

When an AC signal is applied, the current is half the time positive and half the time negative. So the electrons drift both ways and on average do not move. Actually, when an AC signal is applied, the wave energy does NOT travel in the wire but rather somewhere mid-air between the "live" and ground. For example, in a coax cable, the energy travel between the center wire and the shield. Now THAT is something classical electromagnetism (AKA RF antenna theory) teaches you.

[Jack]

Additionnal technical precision:

The electrons do not actually leave their "orbits" since the "orbit" is an hybridized orbit involving all the atoms. So in a sense, they leave "their atom" but not the "orbit" which, in a metal or semi conductor, is rather called a "band". They do not leave the band unless you give energy to an electron that is high enough to either ionize it or move it in the valance band depending on the size of the band gap (way high in a metal and roughly K_B time temperature in a semi conductor).

[novosibir]

There are people with a knowledge, that they might write a tech book - or at least the next tech bock out of the 5-10 previous.

OTOH there are people, they may build great sounding tube amps - and I'm convinced, that some of these people really don't care about the 'real' direction of the electrons flow - at least as long, as the current comes through the power cord, when plugged into the wall...

Larry

[jaysg]

Additionnal technical precision:

The electrons do not actually leave their "orbits" since the "orbit" is an hybridized orbit involving all the atoms. So in a sense, they leave "their atom" but not the "orbit" which, in a metal or semi conductor, is rather called a "band". They do not leave the band unless you give energy to an electron that is high enough to either ionize it or move it in the valance band depending on the size of the band gap (way high in a metal and roughly K_B time temperature in a semi conductor).

Thanks Jack. That's basically what I recalled. The water flowing in a hose analogy is what I was aiming at debunking...not that anyone had mentioned it.

It's been a long time since I was subjected to electromasochism. What happens in the DC case? I don't remember that being very different, but it has been a long time and I've slept since the Final.

[edit]Thanks again Jack. Starting to sink back in...I may be able to stop it if I try hard enough...lol.

[Jack]

In the post above the one you quote, I explain what happen in the DC case.

At the end of the wire, the electron leaves the wire to the next component (a solder pad, another wire, etc) replaced by a new one that enters at the other end (DC case).

[mhuss]

There are people with a knowledge, that they might write a tech book - or at least the next tech bock out of the 5-10 previous.

Yes, at least one physicist in this crowd.

...some of these people really don't care about the 'real' direction of the electrons flow...

Good point -- it doesn't really matter, except for the confusion around those confounded diode and transistor arrows.

--mark

[Jack]

[
Good point -- it doesn't really matter, except for the confusion around those confounded diode and transistor arrows.

--mark

And still, for the price these devices are, you can afford to hook them backward

[novosibir]

And still, for the price these devices are, you can afford to hook them backward

Impossible with tubes... they won't fit upside down into the socket

Larry

[Jack]

And still, for the price these devices are, you can afford to hook them backward

Impossible with tubes... they won't fit upside down into the socket

Larry

Well with an old broken NOS socket, anything is possible

[skyboltone]

And still, for the price these devices are, you can afford to hook them backward

Impossible with tubes... they won't fit upside down into the socket

Larry

Yeah, but I know one Moroon that flipped the layout for a tubes up build and ended up with all his tube sockets wired exactly backwards.......