PHY301 Circuit Theory GDB Solution Spring 2013

Diodes are used in all electronic devices but now mostly these are replaced by LEDs. Why is it going so? How are these better than ordinary diodes?

A diode allows electricity to flow in one direction only and blocks the flow in the opposite direction. They may be regarded as one-way valves and they are used in various circuits, usually as a form of protection. There are different types of diode but their basic functions are the same. These are noted below along with examples of diodes in use.The most common type of diode is a ‘silicon diode.’ It is enclosed in a glass cylinder with the dark band marking the cathode terminal. This line points towards the positive of a circuit. The opposite terminal is called the anode.
Generally, diodes do not conduct until the voltage reaches approximately .6 volts, this is called the ‘threshold point’. If the current becomes too high the diode may crack or melt.