In this post I have explained how to make 2 accurate long duration timer circuits ranging from 4 hours to 40 hours, which can be upgraded further for getting even longer delays. The concepts are fully adjustable. A timer in electronics is essentially a device which is used for producing time delay intervals for switching […]
Circuits
7 Easy Sawtooth Waveform Generator Circuits using UJT, IC 555, and Transistors
In this post I have explained how to build 7 types of easy sawtooth generator circuits, using BJTs, UJTs, and IC 555. In a sawtooth waveform the voltage increases slowly in a slanting manner or diagonally, then as soon as it reaches the peak, the waveform voltage suddenly drops to zero. Once it drops to […]
7 Interesting IC 555 Siren and Alarm Circuits
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, […]
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 […]
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 […]
4 Simple Uninterruptible Power Supply (UPS) Circuits Explored
In this post I have investigated 4 simple 220V Mains Uninterruptible power supply (UPS) designs using 12V battery, which can be understood and constructed by any new enthusiast. These circuits can be used for operating an appropriately selected appliance or load, let’s explore the circuits. Design#1: Simple UPS using a Single IC A simple idea […]