Burglar Alarm With Timed Shutoff

Posted on Mar 31, 2013

When SI (sensor) is closed, power is applied to U2, a dual timer. After a time determined by C2, CI is ene

Burglar Alarm With Timed Shutoff
Click here to download the full size of the above Circuit.

rgized after a predetermined time determined by the value of C5, pin 9 of U2 becomes low, switching off the transistor in the optoisolater, cutting anode current of SCR1 and de-energizing Kl. The system is now reset. Notice that (i6x C2) is less than (R7xC$). The ON time is approximately given by:(R7xC5)-(R6xC2) = Ton

Leave Comment

characters left:

New Circuits



Popular Circuits

Speech Recorder (ISD2560)
all about wiring diagram
how to build inexpensive frequency
40 m band direct conversion
Wien Bridge Oscillator
3W FM Transmitters
0-40V lab power supply circuit diagram electronic project using LM723 L146
Bachmann Sound Tips
Site news archive - PCB Heaven
ADA4858-3 used as a PIN diode driver circuit
Single-speed motor excitation power from a braking circuit