Driveway alarms are remote alarm systems that are triggered when
someone enters your driveway or garden. Driveway alarms are
relatively simple to install, and you can probably find one for
less than $100. They are battery-operated and use motion
detection technology to send a signal to the receiver, usually
located inside your home, when somebody walks onto your driveway
or the walkway leading up to your house. Inside, the alarm will
issue chimes or some sort of audible signal when someone is
approaching. The receiver is typically not battery-operated,
relying instead on a nearby outlet, but some models have a
battery backup in case of a power outage.
The range on driveway alarms will vary depending on which model
you buy. Expect at least 100 feet; more expensive alarms will be
able to send signals a greater distance. Before you go shopping,
you may want to measure the distance between the location where
you will place your alarm and the indoor location where your
receiver will be placed.
Simple driveway alarms typically only come with one transmitter
and one receiver. More complex models may come with multiple
transmitters so you can put alarms on multiple driveways or
walkways leading up to your house.
Sensors on driveway alarms are usually designed to withstand
different kinds of weather, but should still be placed in a
relatively protective area. Most driveway alarms will be
designed to be waterproof, able to withstand snow and rain, but
sunlight can sometimes disturb their effectiveness. Most
driveway alarms are programmed not to be triggered when small
animals (for example, under 40 pounds) fly or walk past.
However, blowing branches and shrubs may trigger the alarm, so
it is recommended that you place it where branches will not be
blown into the detection zone on a windy day (or night--you
don't want your alarm waking you up unless there's really an
intruder in your driveway).
Make sure you read the user's manual that accompanies the
driveway alarm you purchase; this will help you place your alarm
in an optimal position.