Diodes have a positive (+) and negative (-) terminal. The negative terminal (cathode) is clearly marked on both the component and in the circuit symbol...
![]() Various diodes. (Enlarge) |
![]() Circuit symbol diode. |
By the term "diode" today one generally thinks only of semiconductor diodes and silicon diodes. All other diodes are identified by an addition to the term (for example: Schotky diode, Zener diode, diode tube, etc).