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Theft preventer alarm - This circuit utilising 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 goes ON when a thin wire, usually as thin as a hair is
broken....(electronic design added 08/08/08) |
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Timed Burglar Alarm - 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 make this circuit very practical. This alarm has normally
open and normally closed triggers. It's on a 555 timer so the alarm will reset
it's self after a certain amount of time. The time is adjustable....(added 11/06) |
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TinyTwo Zone Alarm - (circuit / schematic added 2/03) |
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Touch Activated Alarm (Tony van Roon) - (circuit design added 8/03) |
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Transistor Based Single Zone Alarm - The circuit features automatic Exit and
Entry delays, timed Bell Cut-off and System Reset. It has provision for
normally-open and normally-closed switches and will suit the usual input devices
(Pressure Mats, Magnetic Reed contacts, Foil Tape, PIRs and Inertia Sensors).
(circuit design added 08/08/08) |
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Ultrasonic Remote Control & Alarm - (circuit design added 8/03) |
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Vehicle Anti-Theft Alarm - This car alarm circuit features Exit and Entry
delays, an instant alarm zone, an intermittent siren output and automatic Reset.
By adding external relays you can immobilize the vehicle and flash the lights.
(circuit design added 05/08) |
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Voltage Protection - Safety devices like fuses provide protection against
excess current, but do nothing for transients and short duration spikes of high
voltahe on the power supply lines.This circuit uses the "crowbar" method and
provides fast protection against transient voltage spikes, transients that could
cause damage to sensitive components. (added 08/08/08) |
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Water Level Indicator with alarm - 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 available CD4066, bilateral switch CMOS IC
to indicate the water level through LEDs. When the water is empty the wires in the
tank are open circuited and the 180K resistors pulls the switch.... (added
10/05) |
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Whistle Responder - Beeps when hears your whistle A gadget suitable for
key-holders, games etc. (added 9/04) |
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Wire Loop Alarm (Aaron Cake) - (circuit design added 8/03) |
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Wireless Home Security Implementing KEELOQ® & the PICmicro® MicroController -
Microchip Application Note Published 12-Oct-99 (app note added 2/06) |
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Wireless Monitoring System - Circuit Cellar June 2004, Issue 167 --
One of the things I have learned from my everyday engineering practice is that
there is always room for ingenuity and improvement. This is particularly true for
this project, which applies a couple of inexpensive microcontrollers to an unusual
device: a live-catch mousetrap. |
