Part 4: Diode Applications

Although it is a simple device, the diode has many applications in electronics.

Reverse voltage protection: It is often inserted in a circuit to protect other components from damage due to reverse voltages.

Rectifiers: One or more diodes can be used to change alternating current into direct current. They are often used in inexpensive power supplies designed to operate electronic equipment powered by DC using the AC power from a standard wall receptacle.

Bridge Rectifier: Four diodes can be connected together to create circuit which will utilize both the positive and negative halves of the AC cycle for power. They are available in a special package with four pins for use power supply circuits.

Displays: LEDs are often used to display information in electronic circuits, including the simple "power on" indicator and simple numerical and text display devices.


Light Sensing: Photodiodes have many applications. In the simplest form, they can be used to turn a light on when darkness falls, but they are often used in control circuits as well, such as the photoelectric eye found in most elevator doors to detect the presence of someone in the doorway.