•  
  •  

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

1Pcs New in box Mitsubishi PLC A1SCPU Processor Unit One year warranty
$102.99 1Pcs New in box Mitsubishi PLC A1SCPU Processor Unit One year warranty picture
New Mitsubishi Melsec A0J2CPU PLC Programmable Logic Controller Oneyear warranty
$255.0 New Mitsubishi Melsec A0J2CPU PLC Programmable Logic Controller Oneyear warranty picture
1PC Used NAIS Panasonic FP3 CPU AFP3220C-F Tested It In Good Condition
$171.0 1PC Used NAIS Panasonic FP3 CPU AFP3220C-F Tested It In Good Condition picture
1PC Siemens 6ES7 231-5QF32-0XB0 CPU Module 6ES7231-5QF32-0XB0 New In Box
$450.0 1PC Siemens 6ES7 231-5QF32-0XB0 CPU Module 6ES7231-5QF32-0XB0 New In Box picture
Schneider 140CPU53414A 586 Controller
$1100.0 Schneider 140CPU53414A 586 Controller  picture