In this post I have explained a simple knock activated door security alarm circuit which can be installed by anybody for identifying a guest or an intruder at the door. The idea was requested by Mr. Akhilesh. Circuit Objectives and Requirements My brother is trying to prepare a project for his college is “Speaker intercom […]
Sensors and Detectors
Cell Phone Ring to Flashing Lamp Indicator for People with Hearing Loss
In this post I have explained a simple sound to flashing lamp circuit which can be used for facilitating people with hearing loss, so that they are able to visualize a distant cell phone rings through flashing of a lamp, and immediately understand regarding an incoming call in their cell phone. The following explanation and […]
Differential Temperature Detector/Controller Circuit
The circuit identifies and detects the temperature difference between two sensors and activates a relay when the temperature is not identical on these differently positioned sensors. By: Manisha Patel It’ll also enable you to detect a difference in temperature, although the temperature sensing devices can be set are discretely, using a potentiometer. Operational Details To […]
Very Low Frequency (VLF) Detector Circuit
Low frequencies predominantly cover our earth’s atmosphere. This range of frequency may be created by many different sources which may be quite unknown and strange. A VLF sensor equipment can be made to trace these frequencies for investigating the intriguing secrets hidden behind it. Mr. Steven Chiverton investigates. VLF Receiver for Sensing Lightening and other […]
Make this EMF Pump Circuit and Go Ghost Hunting
EMF pump circuits are devices which are popularly used for the purpose of identifying paranormal activities or entities by generating rapidly rotating magnetic fluxes in the ether. The conventional devices use a spinning magnet fixed over a motor spindle, however these are mechanical types and are prone to wear and tear. Introduction The explained circuit […]
Deep Soil Metal Detector Circuit – Ground Scanner
In this post I have explained a simple deep under soil metal detector circuit for evaluating hidden metals such as gold, iron, tin, brass etc by detecting change in the resistance of the relevant soil layers. Bigger physical objects which might be buried within the topsoil could be unveiled through a modification in the electrical […]





