In this post I have explained how to use IC 555 to create 7 interesting siren and alarm sound effect generator circuits. The versatile astable multivbrator configuration of IC 555 allows us to implement it for making various types of sirens and alarm circuits. This becomes possible because an astable is basically a waveform generator, […]
Circuits
5 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. In this post I have explained 5 simple motion detector circuits using op amp and transistor. We also discuss the pinout details of the standard passive infrared (PIR) sensor RE200B. We […]
Very Simple BLDC Motor Driver Circuits using Back EMF
In this post we investigate what’s a BLDC motor and subsequently I have explained regarding the design of a sensorless BLDC motor driver circuit. BLDC CPU Fans Seen those fast moving fans in CPUs, voltage stabilizers, DVD players, and other similar equipment, which work with utmost efficiency, consuming minimum space, current and yet are able […]
4 Simple Battery Desulfator Circuits Explored
In this article we investigate 4 simple yet powerful battery desulfator circuits, which can be used to effectively remove and prevent desulfation in lead acid batteries. The first method uses PWM pulses from a 555 PWM circuit, the second method implements an ordinary bridge rectifier for implementing a 100 Hz frequency based desulfation, the 3rd […]
Lead Acid Battery Charger Circuits
The lead acid battery charger circuits I have explained in this article can be used for charging all types of lead acid batteries at a specified rate. This article explains a few lead acid battery charger circuits with automatic over charge, and low discharge cut off. All these designs are thoroughly tested and can be […]
Simple Frequency Meter Circuits – Analogue Designs
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 […]