+ and _ not so?

Discussion in 'General Technical Questions and Answers' started by KC9IUX, May 20, 2008.

Thread Status:
Not open for further replies.
ad: L-HROutlet
ad: l-rl
ad: abrind-2
ad: Subscribe
ad: L-MFJ
ad: Left-3
ad: Left-2
  1. K9STH

    K9STH Platinum Subscriber Platinum Subscriber QRZ Page

    MB got it right! You can blame old Benjamin Franklin for getting things "backwards"! However, in the late 18th century things were pretty much "seat of the pants" and no one had any real idea of how things actually worked.

    Glen, K9STH
  2. K8ERV

    K8ERV Ham Member QRZ Page

    I thot it was the UPhand and DOWNhand rule. I am even more confusider.

    TOM K8ERV Montrose Colo
  3. KI6NNO

    KI6NNO Ham Member QRZ Page

    Wholey hole flow, Batman!

    Haha! That's a pretty good example.

    For the still confused (if there are any):
    "Holes" don't actually flow since there isn't a "hole" particle, there are no positrons in the circuit, and the nuclear particles don't move. Also, you don't have "holes" in an all-metal wire, they only exist in a sense in p-doped semiconductors as an un-filled electron shell valence (or valences).

    Hole flow is a mental construct so that people can visualize the current flow "from" + (B+, Vcc, whatever) to - ( or ground, or - below ground). If you follow electrons from the most negative point in a circuit to the most positive (against the diode arrow for example), that's the way the physical particles are flowing. Out the flat end of a battery and into the pointy side (where it essentially gets gobbled up by the chemical process that frees the electrons in the first place). :D

    Just to be perfectly clear: Nothing moves but the electrons.
    (well, "deathnium" like tin and silver whiskers does, but that's an entirely different subject)

    73, Dave

    Of course there's the exception for mobile "solutions" like KL7AJ mentions next, so if a nucleus is mobile, then it "the hole" can physically move like in electroplating or electrolytes across semi-permeable barriers. I should have known that as soon as I posted, further qualification would be necessary. hihi!
    Last edited: May 20, 2008
  4. KL7AJ

    KL7AJ XML Subscriber QRZ Page

    Actually, this predates the "hole flow" concept by a long time. It actually stems from ion flow, as observed in electroplating and other chemical processes, which were employed long before the electron was discovered. (Of course, they weren't known as Ions then either...but they'd at least figured out that matter was being moved in electrolytic solutions).

  5. KD0DKI

    KD0DKI Ham Member QRZ Page

    Now if I had know this when I was a kid I would have been more "in to" electronics. I could never understand why things seamed backwards.
  6. VA2GK

    VA2GK Ham Member QRZ Page

    Yes, it's always difficult for me when I look at strange (usually old) schematics made by died-in-the-wool engineers where they indicate a current flow from - to +
    Not that it's inexact, it's just not the way I'm used to and it seems non-intuitive.
    Even the junction drawing of the semi-conductor is an arrow that goes in the conventional way, not the electronic way.
  7. K7RQ

    K7RQ Subscriber QRZ Page

    I think the main confusion stemmed from the fact that the early scientists studied electricity without benefit of any knowledge of the makeup of atoms. So all the old "rules" were based on a plus to minus flow which was the prevalent belief at the time.

    I used to tell my night school students to visualize a carton of a dozen eggs on the left and an empty carton on the right. You take one egg at a time and move it to the right-hand carton. When you are all done, two things have happened. All the eggs have gone to the right and all the holes have gone to the left.
  8. AC0FP

    AC0FP Ham Member QRZ Page

    Another way to look at it is the positive charge has a proton surplus. Schematics are drawn in engineering convention which means that the "arrow" indicates the direction of current flow. Sometimes in a negative ground system and using PNP transistors this convention actually helps understanding. Just remember that the electrons in reality do the flowing (moving).

    I believe some military manuals and electronic technician manuals may actually teach current flow with the electrons moving.


  9. K8JD

    K8JD Ham Member QRZ Page

    Ben got a lot of other things right . It was a long time later before Electrons were propposed as the basis of electric current.
  10. K0RGR

    K0RGR Premium Subscriber QRZ Page

    You see, this theory of hole flow also goes along exactly with the explanation for why flashlight batteries are dark inside. It's because when they are hooked up to light bulbs, they suck dark! Over time, the batteries fill up with dark, and lose their charge.
Thread Status:
Not open for further replies.

Share This Page