Organize and Share your Electronics the way you want. Sign-Up for a free account now. It takes only 30 seconds!

Loop Alarm

Loop Alarm

This alarm system was originally designed to protect the contents of a garden shed, although it would also be ideal for other outside buildings. In addition it would offer a good basic security system for small residential areas, such as flats and bedsits. It may be installed without drilling or attaching to the building, which could be an advantage in rented accommodation.
The unit features two separate protection arrangements. The entry/exit is protected using standard normally-open and/or normally-closed sensors such as magnetic switches and pressure mats. Entry and exit delays are independently adjustable, from 5 to 30 seconds, during which time a warning sounder operates and a status LED flashes.

Valuable items are protected by a wire loop system similar to that used in shops etc. This uses a two core cable which is threaded through the items to be protected, and the alarm will be triggered immediately if either core becomes open-circuit or if the two cores are shorted together. Suggestions are given later for making the system even more tamper-resistant.

The loop system can be used independently from the entry/exit system. This would be useful if a shed or garage needs to be left open when working in the garden, while still providing protection for valuable bicycles and power tools.

The unit is battery powered, and will give at least six months continuous operation from a PP9 battery. The alarm sounding period is limited to about sixteen minutes, to conserve battery life and reduce annoyance, but the status LED remains on after this period to indicate that the alarm has been triggered. An optional relay output can be connected to an extra sounder or household alarm system.

Visit Here for more.







 

More Articles to Read

App note: EPIC: Electro-Pyrotechnic Initiator Chip Resistor
App note: EPIC: Electro-Pyrotechnic Initiator Chip Resistor
App note: Noise analysis for high-speed op amps
App note: Noise analysis for high-speed op amps
Skill Sunday: Arrays
Skill Sunday: Arrays
App note: Infrared remote control implementation with MSP430FR4xx
App note: Infrared remote control implementation with MSP430FR4xx
Gesture Controlled Smart Home
Gesture Controlled Smart Home
Design for a Wideband, Differential Transimpedance DAC Output
Design for a Wideband, Differential Transimpedance DAC Output
Wrist thrusters let you fly through the water effortlessly
Wrist thrusters let you fly through the water effortlessly
Bertan/Spellman 225-20R HV power supply teardown
Bertan/Spellman 225-20R HV power supply teardown
Blinking Christmas Lights
Blinking Christmas Lights
Adjusting clock with alarm, hygrometer & thermometer on 1.8″ ST7735 display
Adjusting clock with alarm, hygrometer & thermometer on 1.8″ ST7735 display
Adding an “extra sense” with rangefinders
Adding an “extra sense” with rangefinders
This wireless game controller looks like a rug
This wireless game controller looks like a rug
How to run your ESP8266 for years on a battery
How to run your ESP8266 for years on a battery
Calibration of a 3-Phase Energy Meter Board on the ADE7754
Calibration of a 3-Phase Energy Meter Board on the ADE7754
Making beats on a tiny Arduino DJ controller
Making beats on a tiny Arduino DJ controller
Qinsi-QS5100 Sn63Pb37 solder profile
Qinsi-QS5100 Sn63Pb37 solder profile
Water Detection System
Water Detection System
Professional Hi-Fi 15W Tube Amplifier circuit
Professional Hi-Fi 15W Tube Amplifier circuit
This Arduino machine will judge how sick your ollies are
This Arduino machine will judge how sick your ollies are
Turn an old payphone into a boombox for ’90s hits
Turn an old payphone into a boombox for ’90s hits

Top


Shares