In this post I have explained how to build a simple laptop power bank circuit which can be used for charging a laptop battery during travelling or during outdoor trips. This device can be specifically useful on situations or places where an AC mains outlet is unavailable or difficult to find. Why Laptops Need a […]
Newly Updated Circuit Projects:
3 Simple Frequency Counter Circuits Discussed
In this post we are going learn how to construct 3 different frequency counter circuits using ordinary components and ICs which will showcase the measured frequency on 7 segment displays. The first circuit which uses 4026 ICs can measure frequencies up to 1 MHz and the circuit is user calibrated. We will Learn About: Block […]
How to Make a Simple 200 VA, Homemade Power Inverter Circuit – Square Wave Concept
An efficiency of around 85 % and a power output of more than 200 watts is what you will get from the present design of a power inverter (home built). Complete circuit schematic and building procedure explained herein. Introduction You might have come across many articles regarding power inverters, however you might be still confused […]
Ultrasonic Weapon (USW) Circuit
In this post I have explained a simple ultrasonic weapon circuit also called USW, using very ordinary parts such as IC 555 and a few other passive components to generate the required ultrasonic ear piercing sound. Controlling Crime with USW With rising crime in today’s society, especially against woman, carrying some sort of effective weapon […]
Accurate Speedometer Circuit
Here we’ll see how a simple yet accurate analogue speedometer circuit can be constructed at home using just a single IC and a few external passive components. The speedometer can be universally used with all 2-wheeler, 3-wheeler, even in bicycles for indicating their speeds. Using Frequency to Voltage Converter In my previous article I have […]
Audio Delay Line Circuit – For Echo, Reverb Effects
An audio delay line is a technique in which a given audio signal is passed through a series of digital storage stages, until the final audio output is delayed by a certain period (usually in milliseconds). When this delayed audio output is fed back to the original audio, it results in an amazingly enhanced audio, […]





