The following simple analogue frequency meter circuits can be used for measuring frequencies which may be either sine wave or square wave. The input frequency which is to be measured must be at least 25 mV RMS, for optimal detection and measurement. The design facilitates a relatively wide range of frequency measurement, right from 10 […]
Newly Updated Circuit Projects:
Vehicle Immobilizer Circuit Explained
If you own a car and still haven’t incorporated any security system in it or perhaps your old security system is out of order, you can quickly opt for a cheap yet effective security option for your car or any vehicle by installing the proposed circuit. It will cost you not more than a dollar. […]
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 […]
Simple Digital Clock using LM8650 IC Circuit
The digital time clock explained here is a circuit which most electronic amateurs would love to make. You might have heard about digital clocks made from clock ICs such as the popular LM8361, MM5387 etc but these ICs could be today quite obsolete and/or complex to build. Circuit Operation The present design is much easier […]
5 Useful Motor Dry Run Protector Circuits Explained
The 5 simple dry run protector circuits presented here shows simple methods by which insufficient water conditions inside an underground tank can be sensed without introducing probes inside the underground tank, and thus preventing any possibility of motor dry running. The circuit also incorporates an overhead water overflow control feature. The idea was requested by […]
USB 5V Audio Amplifier for PC Speakers
Audio amplifiers which are designed to work with a 5 V supply from a USB socket such as from a computer USB are called an USB amplifiers. In this article I have explained how to build a simple 3 watt amplifier circuit which can be powered directly from a computer 5V USB port for driving […]