"Which is the positive end of a diode?" is a seemingly silly question, but guess what. I've seen the answers to this question ( Yes, I do mean to be plural, not singular.) cause intense arguments among folks who should have known better.
The two opposing answers are illustrated here:
Yes, this inane semantic argument arose among some of the same crowd who were arguing about whether current flow goes from positive to negative or from negative to positive.
This is why I absolutely refuse to entertain that question. I reject the very phrase straight out of hand because I want to avoid this kind of nonsense.
Instead, I will only refer to the anode end (unbanded) and the cathode end (banded) of a diode, whether the discussion is about rectifier diodes, step recovery diodes, zener diodes, transient absorbing diodes, PIN diodes, varactor diodes, back diodes, light emitting diodes, 5U4GB diodes or any other kind of diodes whose existence might have slipped my mind at the moment.
The one exception I might make to this is for the late Bob Pease's invention, the "Mogen Diode":
As a college student I worked installing tires and batteries. I learned the negative terminal of a battery is the anode, which I found very confusing. That's because the name doesn't come from the polarity in a circuit. It comes from the internal operation. It is called the anode because negatively charged anions flow toward it. In a conducting diode this will make the anode more positive than the cathode. In a battery the anode will be more negative than the cathode.
Posted by: rickman | December 04, 2011 at 08:33 AM
As a non-electrical engineer, arguements like this drive me crazy. It's as if they're deliberatly constructed to confuse the uninitiated. It would be much more helpful to discuss the practical applications of the diode, as in how to wire it into an actual circuit, than to argue about which way we should state the current is flowing.
Posted by: Jim | December 04, 2011 at 09:56 AM
The right side is the positive end. I not sure why the band would come into consideration. The schematic is the overiding factor.
Posted by: Lamdog | December 04, 2011 at 06:05 PM
I didn't know the Mogen diode was due to Pease. I had assumed it to be a Mossad int(er)vention, designed to remove light (but not heat) from political discussions. Happy Christmas
Posted by: George Storm | December 05, 2011 at 06:47 AM