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.