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schematic

simulate this circuit – Schematic created using CircuitLab

People are taught how to calculate this very simple thing, and the calculation goes from source plus to minus, and the diode is there to make sure the electricity flows in one direction.

However, we also know that electrons actually flow from the negative to the positive.

How does this actually work in real life?

user3635998
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    "How does *this" work in real life? " **What** exactly? Electron flow through a diode? Electricity in general? I think there's no real question here, you're just forgetting that everything we know about reality and physics really is just a model, and the closer to reality you get, the less practical these models become. So, the actual flow direction of electrons doesn't matter. The model you've learned works for this circuit. But it's just a model, which doesn't care about in which directions charges migrate. – Marcus Müller Jun 18 '17 at 05:18
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    The flow of electrons and the calculations seem to be in opposite directions. I'm pretty sure the practical side matters, to the manufacturers of the diode at least. Also, I believe that there *is* a question, you just aren't answering it. – user3635998 Jun 18 '17 at 05:25
  • @user3635998 You aren't ready for an answer, I suspect. Let me ask you a much simpler question involving fewer bits to worry about. There cannot be any excess charges in a wire, so the number of mobile electrons must everywhere equal the number of positive atomic cores and the copper is electrically neutral, as it must be. Electrons cannot "push" each other, as any repulsion from one direction is always compensated by a positive attraction from another. So how is it that electrons move in a wire, at all? Answer that correctly and I may have a shot at a better explanation about diodes. – jonk Jun 18 '17 at 05:39
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    We generally talk about "conventional current" which flows from the positive terminal of the battery, through the external circuit, and returns to the negative terminal. Atoms and electrons hadn't been invented when the early scientists were studying electricity so they arbitrarily declared this "conventional current" direction. Although we now know that negatively charged electrons carry the charge in most materials, we rarely need to deal with the actual charge carriers so we almost always deal with conventional (positive) current. – Peter Bennett Jun 18 '17 at 05:41
  • Closely related question: [Which way to draw diode in a circuit diagram](https://electronics.stackexchange.com/questions/31825/) – The Photon Jun 18 '17 at 13:44
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    Unfortunate that the people here dont know the answer and only know how to vote down. – user3635998 May 17 '18 at 03:54
  • @jonk How do you decide whether people are 'ready' for an answer or not? And what exactly is 'ready' for an answer? – Niteesh Shanbog Oct 31 '18 at 10:26
  • @NiteeshShanbog I said I "suspect." That's tentative, not conclusive. But each of us has a right to their opinion based upon what we read, our experiences here and elsewhere, etc. We also each have a right to decide when and if we want to respond, at all. All this is voluntary and speaking only for myself I'm here to actually try and help. You've only to look at my answers to others to see that fact. I'm answering your odd question, in fact, in the same vein. Answer me back, "What did you seek to say or resolve by asking me those two questions?" – jonk Oct 31 '18 at 14:40
  • Except the question isn't about which way to draw the diode in a circuit diagram. stack is full of people that are full of themselves. – user3635998 Nov 02 '18 at 12:58

1 Answers1

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Conventional current is the total flow of charged carriers.

In an electrolyte, these are both positively and negatively charged ions. In a plasma, electrons and positively charged ions. In ice, it's protons that flow to conduct electricity. In N and P type semiconductors, it's mostly electrons and holes respectively, but in intrinsic (undoped) semiconductors, it's a more even mix. In metals, it's just electrons.

It's rather metal-chauvinistic to concentrate on metals and get uptight about electrons having a negative charge, when there's such a diversity of current conduction mechanisms available, using both negative and positive charge carriers. The pioneers of electrical theory and measurement chose one way, but they could have just as easily picked the other. Then I guess people would have objected to the centres of atoms being negative!

The diode has three junctions in it, metal-N, N-P, and P-metal. Different things happen at each junction, only the middle one is what we'd call a rectifying diode.

Use your favourite search engine to find out how doped semiconductors conduct electricity, and how metals do, and how the junctions work. There's much too much information in those topics for a simple answer here.

The schematic you've shown models at the 'conventional current' level, and is not concerned with what particular charge carriers are involved at various parts of the circuit.

Neil_UK
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