Search results for alarm

This circuit features exit and entry delays, an instant alarm zone, an intermittent siren output and automatic reset. By adding external relays you can immobilize... [read]

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... [read]

A simple thermistor triggered cold switch with adjustable threshold.... [read]

This is a complete alarm system with 5 independent zones suitable for a small office or home environment.... [read]

This circuit features automatic Exit/Entry delays, timed Bell Cut-off and System Reset. It has provision for normally open and normally closed switches and... [read]

This device monitors a fuses in your circuits. LED turns on when fuse is blown.... [read]

This circuit serves to silence the arming beep yet maintain the alarm by introducing a small delay into the signal. It sits between the alarm and horn relay.... [read]

Most of the power supply failure indicator circuits need a separate power supply for themselves. But the alarm circuit presented here needs no additional supply... [read]

This circuit utilizing a 555 timer IC can be used as an alarm system to prevent the theft of your luggage, burglars breaking into your house etc. The alarms... [read]

This circuit gives out an alarm when its sensor is wetted by water. A 555 astable multivibrator is used here which gives a tone of about 1kHz upon detecting... [read]

This circuit not only indicates the amount of water present in the overhead tank but also gives an alarm when the tank is full. The circuit uses the widely... [read]

In this circuit, the alarm will be switched on under the following four different conditions: 1. When light falls on LDR1 (at the entry to the premises). 2.... [read]

This FM radio-controlled anti- theft alarm can be used with any vehicle having 6- to 12-volt DC supply system.... [read]

This circuit warns the user against fire accidents. It relies on the smoke that is produced in the event of a fire. When this smoke passes between a bulb and... [read]

The circuit presented here wakes you up with a loud alarm at the break of the daylight. Once again the 555 timer is used here. It is working as an astable... [read]

This is a simple but effective alarm circuit which can reset its self after a time that you select. it has normally open and normally closed triggers which... [read]

Secure any electronic device using this electronic keypad. Circuit is relatively simple and it's built with 4081 CMOS quad 2 input "AND" gate... [read]

This preamplifier has a low output impedance, and is designed to drive long cables, allowing you to listen to a remote music source without having to buy expensive... [read]

This tiny circuit comprising of a single 3 terminal IC UM66 can be built small enough to be placed inside a greeting card and operated off a single 3V flat... [read]

When the circuit detects that a phone line has been cut, it activates a MOSFET which can be used to drive a relay, motor, etc. It can also be connected to... [read]

The 555 is proved to be the most versatile and ubiquitous IC all over the world.This is a possible use: simple inverting schmitt trigger.... [read]

This article is about a software controlled, parallel port-interfacing 8-channel Pulse-Width-Modulated fan controller.... [read]

This circuit is sensitive to low frequency electromagnetic radiation and will detect for example hidden wiring or the field that encompasses a transformer.... [read]

This circuit was designed on request, to remotely monitor when a couple of electric heaters have been left on.... [read]