Security Projects

A Transistor Based – Single Zone Alarm

This circuit features automatic Exit and Entry delays – timed Bell/Siren cut-off – and system reset. It has provision for normally-open and normally-closed switches – and will suit all of the usual input devices (Pressure Mats, Magnetic Reed Contacts, Foil Tape, PIRs and Inertia Sensors). [more]

Posted in : Alarm Projects | security projects

Light-sensitive Alarm Project

The circuit detects a sudden shadow falling on the light-sensor and sounds the bleeper when this happens. The circuit will not respond to gradual changes in brightness to avoid false alarms. The bleeper sounds for only a short time to prevent the battery running flat. Normal lighting can be used, but the circuit will work best if a beam of light is arranged to fall on the light-sensor. Breaking this beam will then cause the bleeper to sound. The light sensor is an LDR (light-dependant resistor), this has a low resistance in bright light and a high resistance in dim light.[more]

Posted in : Alarm Projects | security projects

Garage/Shed Alarm

This is a simple single-zone burglar alarm circuit. Its features include automatic Exit and Entry delays. It’s designed to be used with the usual types of normally-closed input devices such as – magnetic-reed contacts – micro switches – foil tape – and PIRs.It has an extremely small standby current – making it ideal for battery-powered operation.[more]

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Witness camera

The Witness Camera is an automated, self-recording surveillance camera, that uses a gigabyte-class flash card as recording media.It is designed by Alberto.He design the Witnesscam because available surveillance solutions were too expensive or impractical for home use. He built the system from a VGA CMOS colour camera, a passive-infrared (PIR) movement sensor, an ATmega32 processor, and a 1GB SD-card. The prototype looks like an ordinary alarm detector. But when it detects people moving around, it silently starts recording. [more]

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AVR tiny code lock

CodeLock is an AVR based electronic combination lock it is realised with Atmel AVR microcontroller AT90S2313 or ATtiny2313.This project used for access control. Program in hex code is 2 kB long. User code is consisted of 1 to 4 digits. If you buy the chip than user code is consisted of 1 to 8 digits. If the code is entered in the correct sequence, then after 1 second the relay and the electric striker (in the door) switch on for 1 second and then switch off again. User code can be changed via 3×4 matrix keypad.[more]

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