Security and Alarm

A Taser circuit also known as Stun Gun circuit is one non-lethal electric shock producing unit used to paralyze a person for a time being without causing any severe damage or injury. It is a very useful device, especially to immobilize an attacker. Using and making of stun gun is restricted in most of the […]

Pets and kids (under 4) have one thing in common, they are curious by nature and love venturing into unknown zones ending up in some sort of mess or trouble. Pet or kid tracker equipment which are quite similar to a key finder circuit were specifically designed for solving this issue, here I have explained […]

The shop shutter guard circuit discussed here guards your shop when its shutter is closed i.e., at night if an intruder tries to break the shutter, the piezo senses the vibration and the relay is fired to which a 230 volt bulb can be connected which makes the intruder think that someone’s inside…..but he doesn’t […]

A simple earth leakage indicator circuit discussed here can be used for getting some very useful results regarding current leakages from an appliance body into the earth pin. The idea was requested by Mr. SS kopparthy. The circuit of the proposed earth leakage indicator is shown in the figure below. Each such unit may be […]

In this post I have explained a simple ultrasonic weapon circuit also called USW, using very ordinary parts such as IC 555 and a few other passive components to generate the required ultrasonic ear piercing sound. Controlling Crime with USW With rising crime in today’s society, especially against woman, carrying some sort of effective weapon […]

The current controlled circuit of a laser pointer power supply explained in the following post was requested by Mr. Steven Chiverton (stevenchiverton@hotmail.com), who himself is an intense electronic hobbyist and researcher. Technical Specifications Dear swagatam, I’m emailing you to ask you for your expertise, and you being one of India’s finest electronics engineers I thought you be […]