The Fundamentals of a Burglar Alarm System
Summary: The most fundamental design of a burglar alarm system is just a simple electric circuit that sounds whenever a circuit is completed or broken. So fundamental that you can make one yourself.
Today’s burglar alarm systems have gone a long way from being a simplistic device with a solenoid gong that Edwin Holmes has made in 1852. Today’s burglar alarm system incorporates the internet and radio waves, making it really a difficult beat for burglars.
The most fundamental design of a burglar alarm system is just a simple electric circuit that sounds whenever a circuit is completed, or in some designs, broken. This action is called breaking the circuit, and other than your dog maybe the only alarm that guards your doors and windows. How do burglar alarm systems work?
In every electrical circuit, electricity flows on a completed path between two points of opposite charge, negative and positive or input and output. The circuit and the electricity is controlled by means of a switch, an on or off device where you can open or close, or reroute a part of the circuit.
So for example, in a standard circuit that consists of a power supply, a line, switch, bulb, and line back to power supply, every time the switch is turned on the bulb lights. Burglar alarm systems work that way: whenever the alarm is set on active, current passes through the doors and windows. Anyone attempting to open a door will educe the alarm.
One problem though with this design, to stop the alarm you only need to close back the door and the circuit in once again complete. That’s the function of the control box that accompanies most modern alarm system. This control box is connected to all system alarms. Once the alarm is triggered, this control box won’t cut it off until somebody manually cut’s off the circuit. Subsequently, the control boxes are usually hidden and equipped with a lock so the burglar won’t be able to find it.
Because this burglar alarm system is quite rudimentary, you can make one perfectly for your home. With proper knowledge of electricity you can homebrew the Break Circuit Burglar Alarm System (you may call it this way). For ideas relating to such circuits, study how refrigeration lighting comes to play.
Homebrew your Burglar Alarm System
Opening the refrigerator door emits a light. On some designs, the switch is embedded in such a way when you open the door the switch is released, completing the circuit and light goes on. Similarly, embed a press switch on a door frame. Work the circuit in such a way that the pressing will break the circuit and releasing will complete. Now attach the circuit to a buzzer.
Actually, you can imagine many uses with this circuit design. Why, try hooking it up on a disc player and invite your special someone over for dinner. Of course for the dramatic to take effect, you should let her open the door.