Diodes are components that allow current to flow only in one direction. If a diode is placed the other way round (cathode connected to the positive while the anode is connected to the negative) then this will block the current from flowing. This is useful to protect circuits that are connected back to front. Diodes are also used to convert AC (alternating current) to DC (direct current) by having one or 4 diodes. This feature is known as "Half wave rectifier" (for one diode) or "Full bridge rectifier" (for four diodes).
Figure 1: Diode and its symbol
How do they work?
Diodes comes with two bias, which is known as the "Reverse Bias", and the "Forward Bias". The Forward Bias is when the Diode is placed as the conductor, which allows current to flow through the diode at a certain voltage. The Reverse Bias is when the Diode is placed as the insulator, in which current cannot pass through the Diode at a certain voltage. If the voltage exceeds the voltage that the Diode can handle, then the current will be able to pass through the Diode, which will destroy the component. The image below shows a graph of how a Diode behaves.
Figure 2: How Diodes behave
The Schematic
The images below shows the Diode (1N4007) being placed in the forward bias and in the reverse bias. Both of the circuits contain a 5V power supply, an LED, and 330 ohm resister.
Forward Bias Circuit
Reverse Bias Circuit
Testing
The video shows how the circuit performed and the voltage drop across the Diode, which gave similar measurements to what I calculated.
