In the following post I have explained how to drive a relay by using an isolated method, or through an optocoupler device. We will learn three methods, first method is by connecting relay directly with the optocoupler output pins, second method is by using external PNP transistors, and third method is by using external NPN […]
Newly Updated Circuit Projects:
Digital-to-Analog (DAC), Analog-to-Digital (ADC) Converter Circuits Explained
A digital-to-analog converter (DAC, D/A, D2A, or D-to-A) is a circuit designed to convert a digital input signal into an analog output signal. The analog-to-digital converter (ADC) works in the opposite way and transforms an analog input signal into a digital output. In this article I will comprehensively discuss how digital to analog, and analog to digital converter circuits work, using diagrams and formulas. In […]
Laptop Power Bank Circuit
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 […]
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 […]





