In our previous discussion, we explored Light-Emitting Diodes, which emit light when sufficient current and voltage are applied. Now, let’s delve into the broader concept of diodes.
A diode is a small electronic component that serves one primary purpose: to allow current flow in only one direction.
The symbol representing a diode can be seen below:
Diodes possess a specific polarity. In the image above, the stripe on the diodes indicates the cathode, aligning with the vertical line | in the diode symbol. This stripe denotes the intended direction of current flow.
The opposite side is known as the anode, through which current flows from anode to cathode.
When a diode is correctly positioned within a simple LED circuit, the LED will illuminate as the circuit forms a complete loop:
However, if the diode’s direction is inverted, it acts as an insulator and interrupts the circuit, preventing the LED from lighting up:
In digital logic, diodes are commonly used due to their ability to create closed circuits with appropriate voltage and open circuits when inverted voltage is applied. Diodes can be employed to construct AND and OR logic gates.
Additionally, diodes are invaluable in limiting current flow and enabling applications such as AC to DC converters, safeguarding components from reverse voltage, and protecting against voltage spikes, among other uses.
The diodes depicted in the images are known as 1N4007 diodes. They can handle a forward current of 1A and withstand reverse voltage up to 1000V.
Different types of diodes vary in their current-handling capabilities and resistance to reverse voltage.