Electronics > Beginners
Some noob questions
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Mr D:
Thanks!

But how then do i make sense of a component like a diode, in which current can only flow in one direction?

If electrons in reality only flow from neg. to pos., how do the electrons get through the diode and all the way back to the positive terminal?

james_s:

--- Quote from: Mr D on August 16, 2018, 11:34:38 pm ---Thanks!

But how then do i make sense of a component like a diode, in which current can only flow in one direction?

If electrons in reality only flow from neg. to pos., how do the electrons get through the diode and all the way back to the positive terminal?

--- End quote ---

Provided the diode is wired so that the cathode is facing the negative terminal of the battery, the electrons flow through the diode similar to how they would flow through a wire. If the diode is flipped around they don't flow at all, aside from a very small amount called leakage current.

Unless you are working with vacuum tubes you can pretty much forget about the direction electrons are actually flowing and just go with conventional flow, which assumes they go from positive to negative.
Mr. Scram:

--- Quote from: Mr D on August 16, 2018, 11:34:38 pm ---Thanks!

But how then do i make sense of a component like a diode, in which current can only flow in one direction?

If electrons in reality only flow from neg. to pos., how do the electrons get through the diode and all the way back to the positive terminal?

--- End quote ---
You have to remember that the entire convention of conventional current is in reverse. This means that diodes in reality actually work opposite of what we think they do. So if you reverse the flow of electricity but also reverse the direction the diode stops electricity flow, everything is working out again. Electricity is stopped in the direction you'd expect and lets it through in the right direction too.

If you reverse everything it's basically all the same again.
james_s:
Hence my suggestion to not even worry about the details and just use conventional flow. There's a reason it's called conventional flow, all of the schematic symbols are drawn with the assumption that flow is from positive to negative. It's easier at this stage to just operate under this assumption rather than complicating it with details that are irrelevant to most hobby type circuits.
rstofer:
You will notice that in the first 10 seconds of that battery video (all I watched, actually), the author specifically states that he will be looking at electron flow.  Unless there is some chemical reason later in the video (and there might be), that is a regrettable choice.

We use conventional current flow (+ to -).  The current flows in the direction of the arrow in diodes and transistors.  The US Navy used to teach electron flow.  I don't know if they have changed.  Probably not...

As long as you are consistent in marking polarity through components, it really doesn't matter which system you use but you will confuse the vast majority of readers if you use electron flow.
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