The simple alcohol sensor circuit discussed here will accurately sense the emanation of alcohol gas from a selected source, such as from the mouth of a drunkard, when used as a breathalyzer. It’s cheap and a useful device which can be used by all authorized personnel such as a cops or traffic police for nabbing drunken […]
Wireless Music Level Indicator
This simple circuit will create dazzling LED light effect by detecting any music frequency in the atmosphere and by illuminating a 10 LED bar graph meter, indicating the level of music. The proposed circuit is suitable for applications where music and entertainment are involved, such as in parties, festivals, get to togethers etc. Since the […]
Pressure Cooker Whistle Counter Circuit
This circuit is designed to sense the whistles from a pressure cooker and count the number over a digital display. The system relieves the user from the stress of constantly monitoring the cooker and from manually counting the whistles. The idea was requested by Mr. P.K. Bajpai Design Concept In many of the Asian countries […]
DC Motor Speed Controller Circuits with High Torque
Three easy to build speed controller circuits for DC motors are presented here, one using Mosfet IRF540, second using IC 555 and the third concept with IC 556 featuring torque processing. Design#1: Mosfet based Motor Speed Controller A very cool and easy DC motor speed controller could be build using a just a single mosfet, […]
3 Best LED Joule Thief Circuits – Working Details and Video Attached
Technically it may seem impossible to illuminate a 3.3V LED with a 1.5V source, but the amazing concept of joule thief makes this look so easy and effective, and virtually unbelievable, moreover the circuit additionally makes sure that not a single drop of “joule” is left unused in the cell. A joule thief circuit is […]
3 Ideal True/ Pure Sine Wave Inverters using Audio Power Amplifier
If you are not too keen in understanding the deep technical aspects of a true sine wave power inverter, yet want to build it within a couple of hours, then this article will help you to accomplish it using an audio power amplifier and some DC motors. We will consider 3 separate true sine wave […]
4 Simple Clap Switch Circuits using Transistors, Opamp, and IC 555
Want to build a simple clap switch circuit that will toggle any load in response to your claps? The article is presented exactly for this purpose. Here we discuss 4 unique and simple designs which can be selected as per user preference. Overview The article talks about what the title suggests – a clap switch. […]
3 Best 3.7V Li-Ion Battery Charger Circuits using Specialized Intelligent ICs
The post elaborately explains 3 automatic intelligent single chip CC/CV or constant current, constant voltage 3.7V Li-Ion battery charger circuits, using IC TP4056, IC LP2951, IC LM3622, with battery temperature sensing and termination facility. Design#1 CIRCUIT DESCRIPTION The first design is probably the smartest one, incorporating the IC TP4056 which is a comprehensive constant-current (CC), […]
7 Modified Sine Wave Inverter Circuits Explored – 100W to 3kVA
The following article presents 7 interesting modified sine wave inverter designs with exhaustive descriptions regarding its construction procedure, circuit diagram, waveform output and detailed parts lists. The designs are intended for learning and building experimental projects by engineers and students. Here we discuss different varieties of modified designs ranging from a modest 100 watt to […]
How to Make a Wireless Robotic Arm using Arduino
This robotic arm circuit which can be also implemented like a robotic crane, works using 6 servo motors and can be controlled through a microcontroller remote control, using an Arduino based 2.4 GHz communication link. Main Features When you are building something as sophisticated as a robotic arm, it must look modern and must include many […]
USB 5V Audio Amplifier for PC Speakers
In this article we will learn how to build a simple 3 watt amplifier circuit which can be powered directly from a computer 5V USB port for driving an 8 ohm 3 watt speaker. You can build a couple of such circuits and use them for creating a stereo output into a pair of 8 […]
50 Best Engineering Projects for Final Year Students
In this post we sort out a list of most popular, 50 hand-picked and best engineering circuit projects specially created for all aspiring engineers for their final year project exhibition. The circuit projects include the latest and advanced microprocessor Arduino based designs with full program code. The list also includes projects using discrete parts which […]
Using Single Switch for Fog lamp and DRL Lamp
The post explains an easy method of upgrading your existing car fog lamp switch such that it allows toggling both the fog lamp as well as the DRL lamps alternately, as per the owner’s requirement. The idea was requested by mk karthick. Concept Specification Am looking for a circuit which is directly connected to the fog […]