So. Ya’ll must be as sick of this topic as I am of thinking about it :). I wanted to clarify and to posit an answer that for now my brain can wrap around.
So my question was: The question is if current/electrons go from the negative side of the battery to the positive side of the battery, how do diodes only allow current to go from anode to cathode (or P to N)?
This confused a lot of people (like 6 people that I’ve asked) and they started talking about the depletion zone because I don’t think they read the entire question. If you only considered the “How do diodes only allow current to go from anode to cathode” question, you’d think that I didn’t know about depletion zones and start explaining. And I actually do…SO.
Consider please then the entire question. Given how diodes function in a particular set up relative to its power source/battery, and that electrons move from the negative side of a battery to the positive side of a battery, how can we say current (coulomb of electrons/second) flows from P to N in a diode when electrons clearly flow N to P? Sub questions that spin off of this then are:
- What direction does the diode actually block current from? P or N?
- When you’re putting these diodes in a circuit, don’t you think of them as blocking electrons from a certain direction? So which direction do you put them in - backwards?
So first off, don’t let these sub questions confuse you - these are some of the questions I thought of because I was extremely confused.
So I have been told I am referencing TWO different “naming conventions” in the same question - the conventional flow theory and the electron flow theory. Current only flows from P to N according to the conventional flow theory and current flows N to P according the electron flow theory. So really, asking that question like that is confusing. Also the general consensus is that the symbol is in fact written backwards - so I’ll work that in next.
And to address the sub questions, we need actually to take a step back and look at a circuit. I choose to do it electron flow style.
Okay. So what can easily throw off someone such as myself is the actual freakin symbol (which is known to be backwards). I personally think about circuits with regards to how electrons/charge flows through them. So I’m going to change the symbol!
So my answer to this dilemma is to look at it via electron flow instead of conventional flow - and to change the diode symbol so that it doesn’t indicate direction. The only important thing for diode function is its P-N orientation compared to the power source.
As long as the power source and diode are oriented + P N - charge will flow.
As long as the power source and diode are oriented - P N + charge will not flow.
So when thinking about AC current for example, it’s as if the battery is constantly changing from being oriented + - to - +. This will make it so that the diode ends up blocking current whenever the battery’s in the “wrong direction”.
I think this solves it? Yes? Hopefully? (Heck it’s my own question and I deem it solved :p)