Low Cost Burglar Alarm For Boats

Posted on Feb 5, 2014

This low-cost burglar alarm employs a 12V strobe light and a truck reversing horn as the visible and audible alarm outputs while the alarm itself is a 12V horn relay and some pressure mat switches. This simple approach has the benefit that the alarm continues to operate even if the entry point is immediately closed and it draws no current while in

Low Cost Burglar Alarm For Boats
Click here to download the full size of the above Circuit.

the armed condition. To make it independent of the boat supply it runs from a single 12V or two 6V alkaline lantern batteries connected in series. These should last well in excess of two years. An advantage of a lantern battery is that it will last less than an hour while powering the alarm in its active role. This means the alarm system will not seriously contravene noise pollution laws. If there are very strict noise regulations in your area, you can fit an alarm timer, available from some electronic shops, in the circuit between the battery positive and the key switch. The key switch can be installed in the cockpit bulkhead and connects to two normally open (NO) switches wired in parallel. One switch is a pressure mat placed on the cockpit floor near the entry, underneath a suitable piece of carpet or pliable cover. If a pressure mat is unsuitable, the main entry can be protected by a mechanical switch such as an automobile boot lid or door courtesy light switch. The second switch can be used to protect against entry through a forward hatch or second wheelhouse door. Any number of normally open (NO) switches can be installed in this system, all wired in parallel. If the alarm is tripped, the relay closes and latches on due to the wiring of its contacts and the horn and strobe light are powered. The suggested truck reversing horn is the Hella 6023 intermittent reversing buzzer which has an 85dB sound level and a current...

Leave Comment

characters left:

Related Circuits

  • New Circuits



    Popular Circuits

    White LED Stroboscope
    Motion-detection Digital Camera circuit
    Stereo PC Speaker Powered USB Speaker Schematic Diagram
    How to properly snub transient spikes from a transformer and prevent switch mode power supply burn out
    Q Meter
    FT0 frequency synthesizer circuit
    Rain Sound Generator Using NE555 PCB
    The uTracer V3 a miniature Tube Curve Tracer
    Electronic Locks Circuits
    Light Tracking Servo System
    Tube Tune-A-Lite ID37856
    Bad book is not binding circuit