This shadow detector circuit operates using two LDRs and effectively detects the difference between the light levels and triggers a loud audible warning siren. In circuits which uses a single LDR (photoresist), the detection may not be as sharp as with two LDRs discussed here.Operational details of the shadow detector circuit may be studied as […]
Sensor
Simple Ultrasonic Sound Sensor Alarm Circuit using Opamp
This article discusses a simple ultrasonic sound sensor alarm circuit which may be appropriately set for detecting sound pressures well above the normal human listening capacity, that may range from 20 kHz and over. Ultrasonic Concept Ultrasound or ultrasonic sound waves was probably invented even before humans existed on this planet by a few of […]
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 […]
Car Tank Water Sensor Circuit
In this article I have explained a simple car tank water sensor alarm circuit using IC 555 and a pulsating signal on the sensing probes to pevent corrosion on the probes. The idea was requested by Mr. Peter. Circuit Objectives and Requirements I couldn’t find how to post a project proposal on your website. May […]
4 Simple Proximity Sensor Circuits – Using IC LM358, IC LM567, IC 555
Video Demonstration An IR proximity sensor is a device which detects the presence of an object or a human when it is within a predetermined range from the sensor, through reflected infrared beams. Three useful proximity sensor concepts are explained here, the first concept is based on an ordinary opamp LM358, the second one using […]
Non-Contact Current Sensor Circuit Using Hall-Effect IC
In this article I have explained about a simple non-contact current sensor circuit using a hall effect sensor IC. Why Hall Effect Sensor When it comes to sensing current (Amps) linear Hall-effect devices are the best and the most accurate. These devices can sense and measure current right from a few amps to many thousands. […]