General > General Technical Chat
Does current flow through a Battery?
TimFox:
--- Quote from: SilverSolder on October 24, 2021, 04:02:04 pm ---
--- Quote from: GlennSprigg on October 24, 2021, 12:14:48 pm ---
--- Quote from: TimFox on October 22, 2021, 02:36:47 pm ---"Displacement current" was discovered in the 19th Century and is included in Maxwell's Equations to explain the current through a capacitor.
Ionic current in batteries is similar to ionic current in salt-water solutions.
Current is a more general term than the motion of electrons in a vacuum tube.
--- End quote ---
Sorry Tim.... I love you as a tech contributor here, (I highlighted in BOLD your last sentence of concern)...
Again, it seems to be about 'nomenclature' and not about present acceptance of 'standards' ??
I 'guess' I'm taking it to my grave then... but I can NOT accept that there is 'any' CURRENT flow that is 'not' involving
actual 'Electrons', as we understand today... and I will never think any other way! :palm:
--- End quote ---
Here's an interesting mind-bending thought experiment for you:
1. Grab an air capacitor with two plates.
2. Put a flat copper coil between the two plates (e.g. one to 10 turns). Place it flat like the plates, right in the middle of the gap, but not touching the capacitor plates.
3. Apply a moderate frequency AC voltage to the air capacitor, say 1KHz, so we don't have to deal with RF radiation
Q: Will the coil pick up a signal (indicating that a current is flowing through the middle of it)?
--- End quote ---
An interesting thought-experiment (sounds better in German). To be correct, the coil needs to be shielded against the electric field between the plates—this is often done with a few turns of coax, where the magnetic field sensing is done between the two ends of the inner conductor, and the shield is either grounded at one end only, or grounded at both ends with a gap in the center. The AC displacement current between the plates can be calculated from the capacitance (also frequency and voltage), and the emf in the coil follows. An interesting quantitative exercise for the reader.
TimFox:
--- Quote from: bdunham7 on October 24, 2021, 03:12:11 pm ---
--- Quote from: GlennSprigg on October 24, 2021, 12:14:48 pm ---I 'guess' I'm taking it to my grave then... but I can NOT accept that there is 'any' CURRENT flow that is 'not' involving
actual 'Electrons', as we understand today... and I will never think any other way! :palm:
--- End quote ---
What would you call a beam of protons or alpha particles?
--- End quote ---
For example, the original CERN proton synchrotron has a circumference more than 600 m. Along that path, current is carried by positive particles (usually protons). For practical reasons, the current is pulsed, and the strength of the current pulses is monitored by passing the beam down the axis of sense coils.
TimFox:
I only post trigger warnings when Bessel functions are involved.
Alex Eisenhut:
--- Quote from: bdunham7 on October 24, 2021, 03:12:11 pm ---
--- Quote from: GlennSprigg on October 24, 2021, 12:14:48 pm ---I 'guess' I'm taking it to my grave then... but I can NOT accept that there is 'any' CURRENT flow that is 'not' involving
actual 'Electrons', as we understand today... and I will never think any other way! :palm:
--- End quote ---
What would you call a beam of protons or alpha particles?
--- End quote ---
Uh, the Strategic Defense Initiative?
SiliconWizard:
So does current actually flow at all through anything? >:D
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