Current flow (direction) is the topic I’m planning for my next AddOhms tutorial. While preparing the script, I started to realize there are some myths or misunderstandings about electricity and current flow.
Everyone probably knows Ben Franklin. He discovered electricity, of course! Yet, he didn’t. Franklin was the first to prove that lightning was composed of electricity with his famous kite experiment. He was also the first to provide electricity’s well-known labels: positive and negative. And somewhere in there Franklin became famous for “inventing” conventional current flow.
This convention creates a lot of confusion around conventional and electron current flow. It’s a concept that has been covered by many others and may even be covered by an Electronics Tutorial Video Series in the future.
Instead, I want to explore some common current flow myths even I believed at some point.
Myth #1: Electric Current is a flow of electrons
First, I have to admit that I have been guilty of propigating this myth myself. In my AddOhms videos and when teaching electronics classes, I have said these exact words. And they are wrong.
Yes, it is true that the electrons are moving, or flowing. However, the electric current is the flowing charge.[shareable]Electric Current is the flow of charge.[/shareable]
Both the electrons and the charge itself are moving but at different rates. It’s the movement of the charge that creates an electric current. The already moving electrons carry the charge. One important point is that the electron isn’t the only charge carrier. Either an electron OR proton can be a charge carrier.
Protons and Electrons have different mass but hold the same charge. It is easier for electrons to move, compared to protons. I guess you could say: protons are very codependent. No? Okay.
Myth #2: Electrons are the flowing energy
Electrons and Protons are matter. They are not energy! When electrons move they, temporarily, carry the charge of the energy, but they are not energy themselves.
If the electrons are matter, and they are moving, then why don’t we feel the particles moving on a wire? The movement is circular, so mass doesn’t build up anywhere, and the mass of an electron is very, very small. Also, electrons move very slow. The energy, on the other hand, moves fast.
Myth #3: Only Electrons Flow
In the common metals used in interconnects like PCB traces and wires, it is true that the electrons are moving. However, there are materials in which the opposite is true and protons move, carrying a positive charge.
In batteries and wet electrolytic capacitors, ions are moving.
Myth #4: Batteries (or Generators) create electrons
This one is probably obvious to some people, but I wanted to include it anyway. Neither batteries nor generators produce electrons. Instead, they push around the electrons that already exist in the wire and the circuit. In other words, the battery (or generator) is a pump.
Batteries pump electrons around, creating current flow when they convert their chemical energy into electric energy. By pumping the electrons around, they give a path for the electric charge (energy) to flow.
See the difference yet?
Nothing I have put together in this post is new. However, the terms used have been put together with care.
- Electricity isn’t a thing. It’s a concept.
- Electric Current isn’t (just) electrons moving.
- Electrons aren’t the only thing that can move.
I plan to take another approach in the next AddOhms Video. If you aren’t already subscribed, you might want to Subscribe to the AddOhms YouTube channel now![Question]What current flow and electricity concepts have you found confusing in the past?[/question]
Hi, I don’t quite get it with the first one. You say electric current is the flow of charges but an electron is a charged particle. It’s a little confusing…
Okay, I get the concept. When I look at a basic LED circuit, though, I’ve been told that the current-limiting resistor should be placed on the anode side of the LED. That makes sense in a conventional flow context. But it makes NO sense to me using the negative-to-positive “real” flow direction. Why can’t the CL resistor go on the cathode side? (Or _can_ it, and I’m just drinking somebody’s Kool-Aid?) Thanks.
Oh duh. Never mind, I answered my own question … an LED is a DIODE. Long day yesterday, today’s a recuperation day. I shouldn’t be trying to learn anything in this state. Apologies.
I’m not sure what that means. For a diode, or LED, a current limiting resistor can be in either side. The current analysis method used doesn’t matter.
There could be other reasons to place a resistor in a specific side, but it has nothing to do with “current flow direction.”
People waste WAY to much time on current flow direction. It doesn’t matter. Pick an analysis method and stick with it.
It wouldn’t change what side of a LED you put the resistor.
If someone tells you the order matters, they don’t what they are talking about.
It would be the same as saying, make sure you wear a coat or you’ll catch a cold!
Hello james, nice job on your work, i wanted to know that do you have skype or whatsup accounts inorder for us to send our own thoughts and questions about your articles as voice messages?
I am not interested in receiving voice messages. Nor do I provide one-on-one support.
You wrote: ” Franklin was the first to prove that lighting was composed of electricity with his famous kite experiment.” Should that have been: “…lightning…”?