•  
  •  

Timed Burglar Alarm

Contributed by, Richard Johnson

N/O – N/C 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 with the variable resistor in the circuit. The alarm has a reset switch which you can replace with a key switch to make it more secure, and you can change the triggers to other types of door or window switched too. The alarm uses a relay which is connected to a siren but you can replace the siren with whatever you want. The circuit is running off 9VOLTS but can range from 4V – 16V.

If there are any problems please contact webmaster@electronic-circuits-diagrams.com

Please share & like

3x Siemens 3NE4121 Sitor Hls-Sicherungseinsatz 3NE4 121 Semiconductor Fuse-Link
$95.11 3x Siemens 3NE4121 Sitor Hls-Sicherungseinsatz 3NE4 121 Semiconductor Fuse-Link picture
NEW SMC 3 DA 4803 SEMICONDUCTOR MOTOR CONTROLLER
$44.99 NEW SMC 3 DA 4803 SEMICONDUCTOR MOTOR CONTROLLER  picture
The Microelectronics Data Book 2nd Edition 1969 Motorola Semiconductor Products
$17.95 The Microelectronics Data Book 2nd Edition 1969 Motorola Semiconductor Products picture
The Semiconductor Data Book Fifth Edition 1970 Motorola Semiconductor Products
$21.95 The Semiconductor Data Book Fifth Edition 1970 Motorola Semiconductor Products picture
Brush SF 25X80 Semiconductor Fuse 80A
$11.96 Brush SF 25X80 Semiconductor Fuse 80A picture