Category Archives: Technology

Basic logic gates

In any digital electronics textbook you will find description on various logic operations and different logic gates; e.g. AND, OR, NOT, NAND, NOR, XOR and XNOR. But AND, OR and NOT these three gates are known as basic gates. Because you can design any other logic gates or digital electronics circuits using only these three… Read the rest

Electronic and electric

Sometimes these two words are confusing for many of us. As we know electricity is flow of electrons, what is the distinction between the two; where a transistor or a diode also allows the flow of electrons? In simple words electronics is a branch of engineering where current through vacuum tube, gas tube or semiconductor… Read the rest

Phone charger as a power source of logic gate experiment

We know minimum 5V DC is required for logic gate ICs. I do use an old phone charger as the power supply for simple logic gate experiments. Usually phone charger output is 5V DC. I think you can also try it, if you want to do simple logic gate experiments at low cost. You can… Read the rest

Moisture checker circuit for rooftop garden

This is a simple hobby circuit that will make youngsters familiar with electronic circuits and components. It’s possible to monitor moisture condition of soil in a tub with electronic circuit to decide whether more water is needed or not. The variable resistor of this circuit makes forward bias of the transistor, which turns the LED… Read the rest

IMEI

Almost every mobile phones, mobile communication devices and satellite phones have a unique number which is called International Mobile Equipment Identity (IMEI) number. This number is used to identify a specific device. If the device is stolen, it’s possible to blacklist that device so that it can’t be used in any network. It is possible… Read the rest

Exclusive NOR or XNOR gate

In the exclusive OR or XOR gate section we have seen how XOR gate works and how simple it is. Exclusive NOR or XNOR gate is also like a XOR gate, the only difference is we put a NOT logic in the output of a XOR gate and XOR gate becomes a XNOR gate. That… Read the rest

Exclusive OR gate (XOR gate)

Exclusive OR gate is also known as EOR gate or EXOR gate. This logic gate may have two or more inputs and XOR gates always have one output. Its logic is as simple as previously discussed logic gates. Just think the meaning of the word ‘exclusive’; XOR gate output logic is true (high) when only… Read the rest

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