Light-emitting diode is known simply as “the LED”.
The diode made of a compound of gallium, arsenic and phosphorus, that can emit visible light when electrons are combined with holes. So it can be used to make LED.
LED is used as an indicator light in circuits and instruments, It can also be displayed in text or number.
Gallium arsenide phosphide diodes emit red light;
Gallium phosphide diodes emit green light;
Silicon carbide diodes emit yellow light.
As shown in the figure, It is the circuit diagram of flashing single LED application.
The flashing LED operates at a low hertz frequency, it is easy to attract people’s attention. So it can be widely used in various alarm circuits, such as temperature, liquid level, and voltage limit alarm circuits.
It is a type of semiconductor diode that can convert electrical energy into light energy;
Both Led and ordinary diode, consists of a PN junction with unidirectional conductivity.