The motion sensor circuit explained in the article works by using doppler shift principle, in which the moving target is detected through the continuously varying frequency, reflected from the moving object. What is Doppler Effect One very fascinating feature of sound is the Doppler effect. The Doppler effect happens when the source that is producing […]
Detector
Anti Spy RF Detector Circuit – Wireless Bug Detector
A anti-spy or bug detector circuit is a device that detects hidden wireless electronic devices such as wireless microphones, spy cameras, Wi-Fi devices, GPS trackers or any gadget that emits some kind of radio frequency (RF). The proposed design can be specifically used as: Overview Also called anti spy RF sniffer, these are usually used […]
Alcohol Detector Meter Circuit using MQ-3 Sensor Module
An alcohol detector is a sensitive device which is able to detect the presence of alcohol molecules or any similar volatile inflammable element in the air and convert it into equivalent level of electrical output. The simple alcohol detector circuit discussed here will accurately sense the emanation of alcohol gas from a selected source, such […]
5 Simple Motion Detector Circuits using PIR
A PIR motion sensor alarm is a device which detects the infrared radiation from a moving human body and triggers an an audible alarm. In this post I have explained 5 simple motion detector circuits using op amp and transistor. We also discuss the pinout details of the standard passive infrared (PIR) sensor RE200B. We […]
Vehicle Speed Detector Circuit for Traffic Police
In this post I will show how to construct a circuit which can measure the speed of any vehicle on roads and highways. The proposed circuit is kept stationary at a place where the vehicles are suspected to over-speed. If any vehicle goes beyond the speed limit, the circuit alerts immediately. We will be looking […]
Color Detector Circuit with Arduino Code
In this post I will show how to construct a circuit which can detect color and trigger respective assigned relays. This project is accomplished using TCS3200 color sensor and Arduino board. Color Sensing by TCS3200 If you haven’t read the previous article, please go through it where we have discussed the basics of color sensing […]