Photodiodes and phototransistors are semiconductor devices which have their p-n semiconductor junction exposed to light through a transparent cover, so that external light can react and force an electrical conduction […]
LDR Circuits and Working Principle
As the name suggests an LDR or Light Dependent Resistor is a kind of resistor that exhibit a wide range of resistance values depending on the intensity of light incident […]
How to Wire a MQ-135 Gas Sensor Module Correctly
MQ-135 is a gas sensor designed to sense or detect gaseous substance and generate a corresponding positive output voltage. In this post we will learn how to connect or wire […]
4 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. The post discuses 4 simple motion […]
Cell Phone Ring to Flashing Lamp Indicator for People with Hearing Loss
The post explains a simple sound to flashing lamp circuit which can be used for facilitating people with hearing loss, so that they are able to visualize a distant cell […]
3 Simple Proximity Sensor Circuits – Using IC LM358, IC LM567, IC 555
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 […]