NOR gate

In this series of ‘digital electronics’ I have already discussed about three basic gates and NAND gate, which is a widely used gate in digital electronics. Now my topic is NOR gate. Definition of NOR operation NOR operation is a Boolean operation where output is true if all operands are false. In terms of NOR… Read the rest

NAND gate

AND, OR and NOT are three basic operations in Boolean algebra; and AND, OR and NOT gates are three basic gates in digital electronics. Actually all logic gates are made of these three gates. Definition of NAND operation NAND operation is a Boolean operation where output is false only if all operands are true. In… Read the rest

NOT gate or inverter

NOT gate is a logic gate circuit which performs NOT operation on input. Its output logic level is always opposite to input. In other words NOT gate inverts its input. Unlike AND and OR gates NOT gate always has single input. NOT gate symbol Truth table for NOT operation Figure below shows a NOT gate… Read the rest

NOT operation

NOT operation is the last basic Boolean operation. We have seen in OR and AND operation that these are performed on two or more inputs. But NOT operation is performed on single input. NOT operation simply gives opposite logic state of its input logic state. i.e. if input logic is 1 output will be 0… Read the rest

OR gate

OR gate is a digital circuit which performs OR operation on inputs. In OR operation section I discussed about the Boolean logic, OR operation. If any input is true the output is true. So OR gate is a digital circuit where output goes to high state (1) if any of the inputs are high. The… Read the rest

OR operation

In AND operation section I have mentioned that there are three basic Boolean operations in digital electronics and OR operation is one of them. In OR operation, if only one input is true then the output will be true. In other words with OR operation we check whether any of the inputs are true (in… Read the rest

AND gate

AND gate is a digital circuit which performs AND operation on inputs. As I discussed in previous section that AND gate gives high output when all inputs are high. In other cases its output must be low (i.e. 0). So we need to design a circuit in that way. Truth table for AND gate Figure… Read the rest

AND operation

AND gate symbol There are three basic operations in digital electronics, i.e. OR, AND and NOT operation. At first I would like to discuss about AND operation. When all the input conditions are true then the output will be true. If one or more input conditions are false, output will be false. In simple words… Read the rest

Sea salt and Table salt

For thousands of years salt was a very important commodity. Producing salt from sea water wasn’t easy but salt was necessary for preserving foods. In fact salt enabled human civilization to preserve foods. It was a very expensive commodity and in sometimes roman armies were paid in salt. The word salary comes from the Latin… Read the rest

How ATM works

Automated teller machine or ATM also known as cash machine gives you money whenever you need. You just insert a plastic card, enter a pin number and the machine delivers the exact amount you asked for. But what goes inside the machine? Cash machine connects to a central data processor where your account details are… Read the rest