Diode

Diode A semiconductor element with rectifying and light-emitting characteristics. Made of germanium or silicon. The first ever diodes were made of vacuum tubes. The diodes in semiconductors are based on PN junctions made by joining P-type semiconductors and N-type semiconductors. In a PN junction diode, current flows from the P-type semiconductor (anode) to the N-type semiconductor (cathode). Basically, it has the characteristic of allowing electrons to pass easily in one direction but not in the other– in other words, it has a rectifying action. There are many different types of diodes. One type is light emitting diodes (LEDs) that emit light and another is constant voltage (zener) diodes in which the current flows from the n-type semiconductor (cathode) to the p-type semiconductor (anode) when the voltage exceeds a certain level. There are also switching diodes and Schottky diodes. ※ Normal diode symbol

※ Constant voltage (zener) diode symbol

※ Light emitting diode (LED) symbol

※ Schottky diode symbol