Logic Gates
Diode
A device that can control the direction of the flow
of a current is a diode; it is made of semiconductor materials such as silicon.
As you can see, the position of the diode can turn the current on
or off. That means, a diode can be used as a one way switch: if the wider end of
it faces a positive terminal of a battery, it lets current through or else it
cuts the current off.
Based on this system, a couple of switches are made
and they are called logic gates.
The input of these gates can be combinations of 'On' or 'Off'
states and they are known as '1's or '0's. These are binary digits, that has been the
basis of the Binary System. The output can also be
'0's or '1's. That means, we can
express the output of these systems in terms of
'1' and '0' - binary digits.
In
other words, the output of the logic gates can be used to interpret the numbers
in binary form. This is the birth of computer systems; they recognize only '0' s and '1's.
The following animations show the major logic gates,
their input's and output's.
OR Gate
AND Gate
NOT Gate
NOR Gate
NAND Gate
E.g.
If the output is a series of binary digits in the
form of 1101, it represents,
1X23 + 1X22 + 0X21 +
1X20, which is 13.
Logic gates are used in almost every electronic
device today that we take for granted; the following animation shows the role
played by them in our humble washing machine. It ensures we get the maximum
service with least loss of resources and safety.
Have you noticed when the motor is turning on? the
right temperature, right water level and of course, the closure of the door -
for obvious reasons.
Practice is the key to mastering maths; please visit this page, for more worksheets.