In this post I have explained a simple automatic PIR controlled ceiling fan circuit for school college use, which responds and switches ON only in the presence of a human (students) in the classroom. The idea was requested by Mr. Souren Bhattacharya. Technical Specifications I am, souren bhattacharya, a high school teacher in west bengal. […]
Newly Updated Circuit Projects:
Types of Thermistors, Characteristic Details and Working Principle
The thermistor name has been devised as a short form for the “thermally sensitive resistor”. The full form of the thermistor provides the general and the detailed idea of the action which is the feature of the thermistor. By: S. Prakash The various different types of the devices in which the thermistor are used include […]
Ultrasonic Smart Automatic ON/OFF Switch Circuit
In this article we are going to build a smart automatic ON/OFF switch using Arduino, which can turn on or off gadgets automatically by sensing the presence of human nearby through the concept of ultrasonic. We are going to use ultrasonic module and Arduino to sense the presence of human which activates the gadgets such […]
Schottky Diodes – Working, Characteristics, Application
Schottky barrier diodes are semiconductor diodes designed with minimal forward voltage and fast switching speeds which may be as low as 10 ns. These are manufactured in current ranges of 500 mA to 5 amps and up to 40 V. Due to these features they become specifically suitable in low voltage, high frequency applications such […]
Ultrasonic Pest Repellent Circuit
The explained Ultrasonic Pest repeller is a device that generates ultrasound or a very high frequency noise in the range of over 20 kHz which becomes useful for repelling or scaring away animals like stray dogs, cats, mice bats, etc. This becomes possible since these animals are able to easily detect the frequencies at this […]
Ultrasonic Detector Circuit [Extend your Ear’s Sensitivity]
The ultrasonic detector or receiver circuit will be able to detect all those high frequency sounds that are beyond the hearing capacity of humans. The units will be able to hear all those frequencies that are perhaps only audible to some animals like dogs, cats and bats. The ultrasonic receiver circuit can be used for […]





