Maker Pro
Maker Pro

Is a negative rail really NEGATIVE?

P

Paul Kendall

Jan 1, 1970
0
I was once taught that NEGATIVE is electron surplus not simply
relative potential, or a "positive" zone of electron depletion.

For example, electrons direct from a battery plate, as opposed to a
positive 24VDC power supply divided into "+ and -" rails by inserting
an earth reference midway, through the use of zeners.

IOW there was no real negative charge there before, so you only have a
positive charge divided into smaller segments.

Apart from whether not not it makes any difference in practice, does
anyone else see the distinction here?

Paul Kendall
 
L

Les Cargill

Jan 1, 1970
0
BobW said:
In my first electronics class (junior high school) I built a power supply
and had the red binding post as the negative side of the supply. Before
hooking up his Simpson vom, my teacher asked me about the polarity and then
scolded me when he found out that I had it hooked up backwards.

I remember answering that it was the electrons that were the things that
moved so they're the source of the electricity and should be the "hot" side.
It took me a while to adopt the conventional current flow mindset. I'm still
not quite over it some 40 years later.

Bob


if Ben Franklin had guessed the other way, there wouldn't be a problem.
 
R

Rich Grise

Jan 1, 1970
0
In my first electronics class (junior high school) I built a power supply
and had the red binding post as the negative side of the supply. Before
hooking up his Simpson vom, my teacher asked me about the polarity and
then scolded me when he found out that I had it hooked up backwards.

I remember answering that it was the electrons that were the things that
moved so they're the source of the electricity and should be the "hot"
side. It took me a while to adopt the conventional current flow mindset.
I'm still not quite over it some 40 years later.
The only time it really makes a difference is when you rub a balloon in
your hair and stick it to the wall. ;-)

For anything else, just invert all of the signs. The arrows on diodes
point in the direction of hole flow.

The thing I still don't understand is how the crt screen knows exactly
which hole to throw out of the phosphor, on a trajectory that exactly
matches the electric and/or magnetic fields through the deflection
plates/coils/ion trap, to land exactly on the tip of the field
emission cathode. ;-)

Cheers!
Rich
 
R

Rich Grise

Jan 1, 1970
0
Les said:
if Ben Franklin had guessed the other way, there wouldn't be a problem.
It'd be a _terrible_ problem! Then the charge carriers would be positrons,
and we'd all be made of antimatter! =:-O

;-)
Rich
 
T

tm

Jan 1, 1970
0
Rich Grise said:
For anything else, just invert all of the signs. The arrows on diodes
point in the direction of hole flow.

The thing I still don't understand is how the crt screen knows exactly
which hole to throw out of the phosphor, on a trajectory that exactly
matches the electric and/or magnetic fields through the deflection
plates/coils/ion trap, to land exactly on the tip of the field
emission cathode. ;-)

Like the diode, they just follow the arrows.:)
 
T

The Great Attractor

Jan 1, 1970
0
The thing I still don't understand is how the crt screen knows exactly
which hole to throw out of the phosphor, on a trajectory that exactly
matches the electric and/or magnetic fields through the deflection
plates/coils/ion trap, to land exactly on the tip of the field
emission cathode. ;-)

good one. And "in mid-air" too! :)
 
T

The Great Attractor

Jan 1, 1970
0
It's not clear to me that Earth is neutral in the absolute
electron/proton balance sense. I've heard the argument that it is, but
it's not entirely convincing.

John

Which way does Lightning ALWAYS travel?

And yes, it IS always the same way.

If the air gets too 'negative' the ground will suck it away eventually!
 
T

The Great Attractor

Jan 1, 1970
0
if Ben Franklin had guessed the other way, there wouldn't be a problem.

I find that a very funny remark.

It would make a great test for up-n-comers at a bar.
 
T

The Great Attractor

Jan 1, 1970
0
It'd be a _terrible_ problem! Then the charge carriers would be positrons,
and we'd all be made of antimatter! =:-O

;-)
Rich

Damnit, Jim! I'm a surgeon, not a aaaaaaaaaaaa..........
 
W

Warren

Jan 1, 1970
0
Les Cargill expounded in
if Ben Franklin had guessed the other way, there wouldn't
be a problem.

And he had a 50% chance of getting it right!!

I suppose he came out ok on the lightning experiment.

Warren
 
T

The Great Attractor

Jan 1, 1970
0
I'm not sure what you're getting at, but there is cloud to ground,
ground to cloud, cloud to cloud, positive and negative lightning.

http://en.wikipedia.org/wiki/Lightning


The ground is the attractor. The cloud carries the excess ions
(electrons grabbed mostly from the air molecules). It ALWAYS goes from
cloud, to ground when a bolt dumps the cloud's load.

The ONLY other is from cloud to cloud, as in "heat lightning".

But all cloud to Earth strokes are downward flows, regardless of how
the leader and plasma propagation might make some of them appear.
 

Similar threads

Top