Diodes

Diodes are semiconductor devices that allow current to flow in one direction only. The main types of diodes include:

1. PN Junction Diode: 

The basic diode, used for rectification (converting AC to DC) in power supplies, allowing current flow in only one direction.

2. Zener Diode: 

Allows current to flow in reverse once a specific voltage (Zener voltage) is reached, commonly used for voltage regulation and protection circuits.

3. Light Emitting Diode (LED): 

Emits light when current flows through it, used in indicators, displays, and lighting.

4. Schottky Diode: 

Has a low forward voltage drop and fast switching speed, used in high-frequency applications like RF circuits and power rectifiers.

5. Photodiode: 

Converts light into electrical current, used in light sensors, solar cells, and optical communication.

6. Tunnel Diode: 

Exhibits negative resistance, used in high-speed switching and microwave applications.

7. Varactor Diode: Acts as a variable capacitor when reverse biased, used in tuning circuits like those in radios and TVs.

Each type of diode has specialized functions in various electronic applications, from power regulation and protection to lighting and signal processing.