[Amps] "Conventional" current flow

Roger (K8RI) k8ri at rogerhalstead.com
Mon Oct 31 04:37:33 EDT 2016


In electronic theory, electrons and current consisting of the electron 
flow in a vacuum tube are in the same directions. If they were not, then 
the mass spectrometers I worked on were really strange.  We used 
electrons to vaporize a material.  these negatively charged particles 
were focused and then the beam was sent through a curved gap between 
charged plates.  The plates were between the poles of a very strong 
electromagnet.  If you started to lose a tool to the magnet, you let it 
have the tool, otherwise your hand would be crushed between the wrench 
and the magnet pole. It'd take a small wrench right through your hand.

At-any-rate, between the magnet and the curved plate, the ions would be 
spread out according to mass, much like a prism spreads light.  If the 
light from an arc is sent through a prism there will be spectral lines 
for the materials in the arc

The materials behave as predicted in real electronic theory.  The 
electrons, if given enough push can erode a target,
As I said earlier, conventional current is imaginary, but in 
"semiconductors"  There are positive current carriers.  A magnet can be 
used to determine the direction of the current flow and whether the 
current carriers are positive.  Positive current carriers exist only in 
semiconductors and ions.

73

Roger (K8RI)


On 10/28/2016 Friday 2:56 PM, Jim Garland wrote:
>> -----Original Message-----
>> From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of Gene May
>> Sent: Wednesday, October 26, 2016 01:39 PM
>> To: amps at contesting.com
>> Subject: Re: [Amps] Amps Digest, Vol 166, Issue 26, reference direction of
> current flow in
>> screen grids
>>
>> Concur with Bill W6WRT re "positive vs negative" convention in describing
> current.  The
>> convention we use now is left over from at least a hundred years ago when
> a scientist
>> guessed wrong about the polarity of the electron.  To me, thinking in
> terms of the direction
>> of electron movement is far more clear.
>> -Gene WB8WKU
> Sorry to disagree with you and Bill,, Gene, but the standard convention for
> electric current makes a lot of sense, and it's not just that somebody
> guessed wrong a century ago about the polarity of electrons. The important
> concept is that electric current is a statistical concept. Electric current
> is sometimes carried by positive charges, sometimes by negative charges, but
> the sign of the charge carrier is an entirely separate issue from the
> direction of current flow.  In a vacuum tube, plate current flows into the
> plate and out of the cathode, even though the motion of the electrons in the
> tube envelope is in the reverse direction.  Similarly, current flows into
> the collector of an NPN transistor and out the emitter (hence the words
> collector and emitter), even though transistor current may be carried by
> holes.  Similarly, current flows out the positive terminal of a battery and
> returns into the negative terminal, no matter whether the charge of the ions
> in the battery are positively or negative. It would be a nightmare to keep
> track of current flow, if the direction of flow depended on the sign of the
> underlying charge carriers.  You might have situations where current flows
> out of a B+ supply to the plate of a tube, and then is annihilated by
> current flowing in the opposite direction from within the tube, coming from
> the cathode.
>
> One further tidbit. In a metal, copper wire for instance, the conduction
> electrons move in all directions. The current is caused when an electric
> field shifts the motion a tiny bit. The so-called "drift velocity" of
> conduction electrons in a current-carrying wire is only about 1 cm/sec. It
> is not, as many people think, the speed of light.
>
> 73,
> Jim W8ZR
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus




More information about the Amps mailing list