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


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

Quantum theory

Suppose you are hitting a ball with a bat and then using Newtonian or classical mechanics you can tell how long the ball will stay on air, how far it will go and trajectory of the ball. Even you can calculate at which speed the ball will hit the ground. To answer all the questions… Read the rest

When people’s teeth exploded like bomb

Yes, there is enough evidence that many people’s teeth exploded like bomb in their mouth. It was in 19th century and it’s still a mystery; no one knows why it happened. The dental cosmos was the first major journal for American dentists, in this journal a Pennsylvania dentist WH Atkinson documented an outbreak of… 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