Have you ever turned up your amplifier all the way, either at a party or just for fun? You may have noticed that “it gets hot” and thought that a fan would be useful. However, at low listening levels, you can hear the fan running. With this circuit, the fan will be automatically controlled by […]
Newly Updated Circuit Projects:
Simple Refrigerator Protector Circuit: Solid-State Delay ON Timer
This simple refrigerator protector circuit is actually a delay ON timer circuit which makes sure that whenever a power failure occurs or in case abrupt power fluctuations take place, the refrigerator is never allowed to switch ON instantly, rather after a delay of a few moments. Conventional Protection Features Today most modern refrigerators are equipped […]
How Electret Microphones Work – Full Tutorial and Diagram
In this post I have explained how electret microphone devices work, through appropriate diagrams and formulas. What’s a Microphone A microphone is a device designed for transforming weak sound vibrations into tiny electrical pulses, which can be then amplified through a power amplifier over a loudspeaker for achieving a louder reproduction of the sound. The […]
Laser Activated GSM Call Alert Security Circuit
In this post I have explained a simple laser GSM call alert security circuit which immediately calls the master as soon as an intruder is detected through a laser beam interruption. The idea was requested by Mr. Roldan. Circuit Objectives and Requirements I am not an electronic engineer, but I can manage to troubleshoot minor […]
7 Best Touch Sensor Switch Circuits Explored
In this post I have explained 8 easy methods of building touch sensor switch circuits at home, which can be used for switching 220 V appliances ON/OFF with mere finger touch operat ions. The first one is a simple touch sensor switch using a single IC 4017, the second one employs a Schmidt trigger IC, […]
Make this Digital Temperature, Humidity Meter Circuit using Arduino
In our previous article, I have explained how to interface temperature humidity sensor with arduino and read out displayed on serial monitor of arduino IDE. In this post I have explained how to display the reading on a 16×2 LCD display for the proposed digital temperature/humidity meter using Arduino. Introduction This project may be used […]





