Copyright © 2004 jsd

1  How to Define Anode and Cathode

2  Discussion

3  Summary

I am astonished that some people take a concept that is simple and unimportant, make it needlessly complex, and pretend it is important.

When dealing with batteries, don’t think in terms of anode and cathode; think in terms of positive terminal and negative terminal.

When dealing with semiconductor diodes, don’t worry about anode and cathode; think in terms of P-doped side and N-doped side.

The general rule is: Anode means current into the black box and cathode means current out from the black box. Zener diodes give rise to an execrable exception that should be avoided like the plague.

There is abundant evidence that even people who call themselves experts cannot keep the anode/cathode terminology straight. In any practical situation, there is always a way to figure out how to hook things up without a deep understanding of anode versus cathode.

In almost all situations, it is better to avoid the terms anode and cathode. There are better ways to say what needs to be said. Constructive suggestion: it is better to talk about the current (rather than the electrode). It is better to talk about what the current is doing (rather than what the electrode “is”).

4  References

John Denker,“How a Battery Works”

Copyright © 2004 jsd