Electrons and color codes

Thread Starter

italo

Joined Nov 20, 2005
205
First of all i don't think electrons know color coding but they happily flow from positive to negative leaving behind holes that of course move in the opposite direction.
Common or grounds can be sitting at +/- 1000 of volts. So the terminology does not enply nothing except as to say things like ground is common to all our circuits or all returns are common, or all grounds are common. On a 120v ac the white is neutral while the black is considered hot and green earth. Most of house wiring follow this code but not in all of the USA it varies from county to county but all have one law no matter what color you start it better end with the same color.
 

thingmaker3

Joined May 16, 2005
5,084
First of all i don't think electrons know color coding but they happily flow from positive to negative leaving behind holes that of course move in the opposite direction.
I think you may have inadvertently inverted your intended implication.
 

thatoneguy

Joined Feb 19, 2009
6,359
Yes, technically electricity flows from negative to positive, but as long as you have a convention of analysis and stay consistent, mathematically it can go the same direction as all the arrows on the semiconductors, making life almost as simple as vacuum tubes not so long ago. -- One of my profs.

Ignore the above if you are a semiconductor/mask designer.
 

Wendy

Joined Mar 24, 2008
22,473
I'd rather go with reality, it's less confusing in the long run. Electricity relates to how atoms are built and their structure. Given no one subject is taught in a vacuum, things like chemistry (and don't forget electronic sensors used in chemistry), physics, and more are all interlinked, I think we'd better teach the correct conventions, and acknowledge the old conventions existed because it was so widespread and in so many old text books.
 

thatoneguy

Joined Feb 19, 2009
6,359
I'd rather go with reality, it's less confusing in the long run. Electricity relates to how atoms are built and their structure. Given no one subject is taught in a vacuum, things like chemistry (and don't forget electronic sensors used in chemistry), physics, and more are all interlinked, I think we'd better teach the correct conventions, and acknowledge the old conventions existed because it was so widespread and in so many old text books.
I agree, the quote above was from an older EE Prof trying to quell the arguing over him "drawing the current the wrong way" in class. One semester, were getting both versions the same day depending on the subject.

I apologize for the hijack.
 

KL7AJ

Joined Nov 4, 2008
2,229
I must have smarter electrons than most people! I can paint different stripes on a resistor, and the resistance changes automatically to match the color code. :)

eric
 

static ore

Joined Mar 3, 2009
10
Okay Italo and oneguy, being a rank beginner does have its drawacks, I know. However, it would be nice to resolve the context of + to - and/or - to + !!!!!!

Oneguy, I have your desertation on the physics forum and I am working on it. However, S/ore
 

PRS

Joined Aug 24, 2008
989
My observation, for what it's worth: Manual and texts for beginners usually stress the negative to positive while engineering and scientific texts use the conventional positive to negative direction. Fuss and feathers, perhaps, but it must confuse the heck out of beginners who learned it one way and then run into a text that has it the other way!
 

russ_hensel

Joined Jan 11, 2009
825
Current flows from plus to minus period. That says noting about the direction of elementrary particles or the fields that are equivalent to currents.
 

beenthere

Joined Apr 20, 2004
15,819
But, as electrons are the charge carriers, it's hard to imagine current as anything but negative charges moving toward a more positive point. Vacuum tube convention and Ben Franklin notwithstanding.
 

russ_hensel

Joined Jan 11, 2009
825
But, as electrons are the charge carriers, it's hard to imagine current as anything but negative charges moving toward a more positive point. Vacuum tube convention and Ben Franklin notwithstanding.
But electrons are only the most common charge carriers, any charged particle produces a current when it moves. That includes protons, for example If you wish you can call it conventional current. You must use it if you want to use Maxwell's equations as they have stood for about the last 100 years. ( I too can use extreme punctuation, but choose not to, this time. )
 

thingmaker3

Joined May 16, 2005
5,084
You must use it if you want to use Maxwell's equations as they have stood for about the last 100 years.
Demonstrate, please. Teach us the difference between amperes per square meter when using electrons and amperes per square meter when using when using holes. Show us that "J" can't work if current is defined as a flow of electrons. Pinpoint for us the change in magnitude of the curl of the magnetic field when we define "current" differently than you.

I've got a box of chocolate-covered exclamation points for you to call your own if you succeed.
 

Wendy

Joined Mar 24, 2008
22,473
But electrons are only the most common charge carriers, any charged particle produces a current when it moves. That includes protons, for example If you wish you can call it conventional current. You must use it if you want to use Maxwell's equations as they have stood for about the last 100 years. ( I too can use extreme punctuation, but choose not to, this time. )
But protons don't move (other than brownian motion), the positive charge is the absence of the electron that has moved on. Unless we are talking antimatter or some other exotic situation, only the electrons move. Holes are just a concept that makes the math easier.
 

russ_hensel

Joined Jan 11, 2009
825
Demonstrate, please. Teach us the difference between amperes per square meter when using electrons and amperes per square meter when using when using holes. Show us that "J" can't work if current is defined as a flow of electrons. Pinpoint for us the change in magnitude of the curl of the magnetic field when we define "current" differently than you.

I've got a box of chocolate-covered exclamation points for you to call your own if you succeed.
Without looking them up it is apparent that if you have a current flowing in the reverse direction and use maxwells equ to determine the magnetic field, you will need a new minus sign, or the magnetic field will be in the wrong direction. Do I need to drag out the specific equations!?
 
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