Diode is made of two different parts. One part is
called p-type and other
part is called n-type.
In between, we call it the p-n junction. P-type is
silicon mixed with boron, and n-type is silicon mixed
with phosphorous. In order to explain how it works,
we must know about the octet
rule and valence
The octet rule is that bonded nonmetialic atoms
has eight electron outermost shell or energy level.
It means that when two chemicals react each other and
produce a product, its outer shell has eight
The valence electrons are the electrons moving
aroung the most outer shell of an individual atom and
they are often involved into chemical reaction
Read more about diode.
(LED and the symbol of LED)
LED emission is visible in the
spectrum wavelengths from 0.4 to 0.7m or
in the near infrared, which we cannot see, that of
wavelengths between 2.0 and 0.7 m.
More than 20 billion LEDs are produced each year.
This device is used in digital circuit
such as computer memories. Computer memories can be
lost during electric power failure, so the capacitor
provides power to maintain information from
temporarily loss of power.
(Capacitor and its symbol)
(Photo resistor and its symbol)
[Ch 11] - [Ch 12] - [Ch 13] - [Ch 14] - [Ch 15]