CRT attraction ?

[vlad777]

If we have two parallel conductors with current in same direction
we have attractive force between them.

I want to ask is there attractive force between
three electron beams in CRTs ?

Many thanks.

 

[birdman0_o]

Don't CRTs only have 1 electron beam.

 

[vlad777]

Color CRTs have three cathodes and each produces a beam which intensity
correlates with color intensity.
Three amps, three colors RGB.

At least I think so.

From wikipedia:
...An image is produced by controlling the intensity of each of the three electron beams, ...
https://en.wikipedia.org/wiki/Cathode_ray_tube

I notice that cathodes are about 1.5 cm apart and subpixels are very close so beams are
either focused or they might attract each other.

 

[Ratchit]

vlad777,

If we have two parallel conductors with current in same direction
we have attractive force between them.

I want to ask is there attractive force between
three electron beams in CRTs ?

Many thanks.

In two wires, with the current existing in the same direction, the formula for the attractive force is µo*I1*I2/(2*pi*d) Newtons/meter, where I1 and I2 are the currents in amps, µo = 4*pi*10E-7 is the permeability of free space in Hz/m, and d is the distance between the two wires in meters. In wires, the electrons are confined, whereas in a CRT, the beams are focused. I would think the focusing probably compensates for any attraction between the beams.

Ratch

 

[ben7]

Don't CRTs only have 1 electron beam.

Only in black & white TVs!!!

 

[Nigel Goodwin]

If we have two parallel conductors with current in same direction
we have attractive force between them.

I want to ask is there attractive force between
three electron beams in CRTs ?

Ask yourself these simple questions:

1) What charge has an electron?.

2) Won't a beam of electrons have the same charge a single one?.

3) What do like charges do?.

 

[KeepItSimpleStupid]

Multiple gun CRT's existed. Up to 10. per this article: Oscilloscope - Wikipedia, the free encyclopedia

ben7:
Does my green oscilloscope trace have more than 1 gun per your definition?

vlad:
Color from one gun. The Sony Trinitron: https://en.wikipedia.org/wiki/Trinitron

 

[Nigel Goodwin]

ben7:
Does my green oscilloscope trace have more than 1 gun per your definition?

Obviously not, and his post made no such suggestion.

vlad:
Color from one gun. The Sony Trinitron: Trinitron - Wikipedia, the free encyclopedia

Three separate beams from the one gun - which has three separate cathodes as well.

The 'single gun' was more a marketing scam than anything else.

 

[KeepItSimpleStupid]

Nigel, please re-read:

Don't CRTs only have 1 electron beam.

Only in black & white TVs!!!

Does my green oscilloscope trace have more than 1 gun per your definition?

and

Obviously not, and his post made no such suggestion.

I infer based on the statements above and my philosophy class:
B&W = 1 gun
Color = more than one gun

What's green?

CRT's can have multiple guns and it's not dependent on color.

from Philosophy:

The grass is green
If the grass is Green then God exists.
Therefore God exists.

This is strictly from my Philosophy Logic class.

It doesn't matter if the statements are correct, but when taken together they either prove or disprove an argument.

 

[Nigel Goodwin]

from Philosophy:

The grass is green
If the grass is Green then God exists.
Therefore God exists.

This is strictly from my Philosophy Logic class.

It doesn't matter if the statements are correct, but when taken together they either prove or disprove an argument.

Philosophy neither proves or disproves anything - it's just a load of rubbish - and your example is probably the biggest load of rubbish yet.

Presumably you're failing the course?

 

[KeepItSimpleStupid]

Nah. got an "A". Even when he pulled the test with all false answers. One wierd course amoung many such as "An Introduction to feminist theory".

 

[MrAl]

Ask yourself these simple questions:

1) What charge has an electron?.

2) Won't a beam of electrons have the same charge a single one?.

3) What do like charges do?.

Hi there,


I would like to add a few other questions to that list here...

4) What is the difference between two charges close to each other, from when they are at rest compared to when they are in motion?
5) What kind of field is produced when a charge moves through space?
6) What happens when a charge moving through space encounters a magnetic field?

Philosophy can be phun (chuckle). The one that i always liked was as follows...

"The barber shaves everyone in the village who does not shave himself".

Sounds reasonable, doesnt it? If someone does not shave them self then the barber must shave them. But then we can ask the little question:

"Then who shaves the barber?"

If the barber shaves himself then he is one of those people who shave them self and so the barber does not shave himself, but the barber does shave himself, so...


Even more interesting is what exactly is a hole? (think of a hole in the ground)

 

[Roff]

Nigel, you can appreciate this little anecdote:
Many years ago, I worked for a company that made timebase correctors. One day, a customer called in with color problems (NTSC, as you might guess). Our chief engineer told him to put color bars through the TBC and look at the green dot on his vectorscope. There was a pregnant pause, and then the guy says - yep, you guessed it - "They're all green!"