How Do Alarm Systems Work?

If you've ever wondered to yourself "How do alarm systems work?" then you've got the kind of curiosity that just needs to be satisfied. While the components of an alarm system can be very high-tech and complicated, when it comes to how alarm systems work, it's actually a pretty simple process.

How Do Alarm Systems Work? It's All about the Circuit

Remember middle school science class when you learned about how electricity travels in a circuit? Most alarm systems work on this exact same principle. Let's do a short review of how electricity works.

Electricity travels through the entire system in one direction. In order to start or stop the flow of electricity, we use a switch. This is obvious when turning on a light, for example. When the switch is in the "on" position, it means that electricity is traveling through the circuit. If the switch is in the "off" position, it means that there has been a break in the circuit, so the electricity is unable to make it from the beginning point to the end point.

How Your Windows and Doors Become Circuits

When answering the question: "How do alarm systems work?" it is helpful to realize that a burglar alarm utilizes your doors and window to create electrical circuits. Creating this kind of circuit is easy. Simply set up a sensor so that one half is on the door frame, and the other half is on the door. In many cases, there is a magnet in one side of the sensor, and a metal switch on the other. Run a small electrical current through the device, and you're ready to go.

When the door is closed, the magnet attracts the metal switch, and closes the circuit. Once the door is opened, however, the two pieces of the sensor become separated, and the circuit is broken. This sends a message, and the alarm is sounded. This same exact tool can be used on a window, where the circuit is broken when an intruder opens it and breaks the connection.

There are other variations on this idea, but most work along the same principle. Once the door or window has been opened, the circuit has been changed, and an alarm will sound. Amazingly enough, even a glass window can be turned into a circuit by attaching a small foil wire. If the glass is broken, the circuit will be, too. It's simply a matter of determining how someone might enter your home and turning it into a circuit.

Of course, there is much more to creating the entire system, but when someone asks, "How do alarm systems work?" the first place to start is with a discussion of the electrical circuit.