Everyone has seen a scene in a film where someone drives up to a huge, gated estate and presses the intercom button to be allowed in.

Yet, even much more modest homes may have long driveways, or ones out of sight from the house. Being able to know when someone – and who – arrives at your house can enhance home security.

Driveway alarms can provide those benefits.

Most work by placing infrared sensors at appropriate spots on the house, beside the driveway entrance, on the gates, or in the yard.

Those are connected to a transmitter that sends a signal to a receiver in the home. Other types emit a dark green light. In either case, a ‘light wire’ is tripped when a vehicle or person interrupts the beam.

Still others use a pressure-sensitive tube in the driveway surface. A magnetic probe type can signal the arrival of a large metal object, such as a car or truck.

But whatever the underlying technology, the purpose and function is the same: to alert on the arrival of someone at the home. That allows detection long before the visitor has reached the house. That can be useful for more than just intruder detection, since it can alert residents to innocent package deliveries or workmen.

Contemporary systems are often accompanied by a motion detector.

That enhances the system, adding the ability to detect human movement, even when someone may step over the driveway beam. The range varies from about 800-1200 feet from the transmitter, providing coverage for a wide area.

Systems come in a variety of levels of sophistication and features. It costs a bit more, but many have an intercom system. That makes them more useful for distinguishing between expected visitors and those who arrive unannounced.

Adding a video camera, a much less expensive option today than in the past, adds yet another useful layer. Seeing the person and their vehicle makes possible the safest level of discrimination between friend and (potential) foe. It can also provide identification in case an intruder is apprehended and tried in court.

Additional useful features can be added to some systems. When you arrive at home, tripping the alarm, it’s possible to have the garage door open, or house lights come on or even the front door unlock automatically.

Some systems come with a battery backup option that keeps the system functioning during a power outage. That’s beneficial when an intruder disables your power system before driving a vehicle past the alarm.

There are several other features one might look for, such as waterproof transmitters, sound volume control, do-it-yourself installation, connection to a home PC network and others. But the most important is the ability to discriminate objects well. False alarms, such as children riding bicycles, dogs running by could drive you crazy very quickly. That would make the system useless.

Check out the many available driveway alarm systems available today. You’ll wonder how you ever got along without one.

Tags: battery backup, Driveway Alarm Systems, driveway entrance, home PC network, infrared sensors, intruder detection, modest homes, pressure-sensitive tube, video camera