•  
  •  

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

PHILIPS 21369A T6210 TEE ULTRASOUND TRANSDUCER/PROBE WITH CASE
$285.0 PHILIPS 21369A T6210 TEE ULTRASOUND TRANSDUCER/PROBE WITH CASE picture
Genuine HP Agilent 21292A Ultrasound U/S Adapter Transducer for Sonos 4500/5500
$34.99 Genuine HP Agilent 21292A Ultrasound U/S Adapter Transducer for Sonos 4500/5500 picture
Untested Siemens 08241113 Acuson 15L8W Linear Transducer Ultrasound Probe
$25.0 Untested Siemens 08241113 Acuson 15L8W Linear Transducer Ultrasound Probe picture
Philips Healthcare C10-3v Transducer ENDOVAGINAL TRANSDUCER
$500.0 Philips Healthcare C10-3v Transducer ENDOVAGINAL TRANSDUCER picture
Philips Healthcare L15-7io Broadband compact linear array transducer
$420.0 Philips Healthcare L15-7io Broadband compact linear array transducer picture