Self-arming alarm


Posted on Oct 10, 2012

The circuit has a built-in, self-arming feature. The driver turns off the ignition, presses the arm button on theComputalarm, and leaves the car. Within 20 seconds, the alarm arms itself—all automatically! The circuit will then detect the opening of any monitored door, the trunk lid, or the hood on the car. Once activated, the circuit remains dormant for 10 seconds. When the 10-second time delay has run out, the circuit will close the car`s horn relay and sound the horn in periodic blasts (approximately 1 to 2 seconds apart) for a period of one minute. Then the Computalarm automatically shuts itself off (to -save your battery) and rearms


Self-arming alarm
Click here to download the full size of the above Circuit.

If a door, the trunk lid, or the hood remains ajar, the alarm circuit retriggers and another period of horn blasts occurs. The Computalarm has a "key" switch by which the driver can disarm the alarm circuit within a 10-second period after he enters the door. The key switch consists of a closed circuit jack, Jl, and a mating miniature plug.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Guitar Effect Bypass Circuit
usb controlled rgb led
Infrared Cordless Headphone Amplifier
touch switch circuit diagram
Radio Circuits
amplifier audio small to use with 9v battery operated
Shadow Alarm Circuit
Antenna Tuning Unit
Multimedia RIAA Preamplifier
Basic Transistor Circuits
PIC12F629 based IR decoder
LED Dimmer Lighting
Level 555 a control circuit diagram



Top