Starting Electronics Needs Your Help!
It is that time of the year when we need to pay for web hosting and buy new components and equipment for new tutorials. You can help by making a donation. Contribute to this website by clicking the Donate button. The total will be updated once daily. (You may need to clear your browser cache to see the updates.)
Target Amount: $2000
Amount Raised: $1960
Top Donor: C.C. $100
Created on: 30 July 2012
A diode allows current to flow through it in one direction only. Two diodes are shown below that are commonly used in electronic projects. The diode on the top has the part number 1N4148 and the diode below it is a 1N4007.
The schematic symbol for a diode is shown below. Notice the similarity between the diode symbol and the LED symbol. The LED is a special type of diode.
A diode has a cathode (-) and anode (+). In the schematic symbol, the tip of the triangle with the line on top of it is the cathode. The cathode is marked on the body of a diode by a band as shown below.
Current can flow from the anode to the cathode only and never from the cathode to the anode – the diode is like a one way valve.