Auto Alarm


Posted on Jan 6, 2013

SI is external key switch. The alarm allows a 0- to 45-s delay after SI is operated before the circuit is armed. During this per


Auto Alarm
Click here to download the full size of the above Circuit.

iod, LED1 lights green. After this delay, LED1 lights red, which indicates that the circuit is armed. Then, sensors S2 through S4 -(NO) or S5 through S6 (NO) pull pin 2 of U2 low, which activates K1 and sounds the alarm. The alarm sounds for a duration determined by R4 and C2. After this time, K1 releases and the circuit is again ready. Manual reset is via the key switch, SI.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Windshield Wiper Interval Controller
DC Motor Controller Circuit with NE555
VU Meter using LM3915
Make the laser harp of the intention by oneself
Gentle Breeze
Step-Down Converter Controller
Analog IO Protection



Top